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FTIR Analysis - Science method

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Hello, I have synthesized a powdery material that is highly sensitive to air and decomposes when exposed to air for a short period of time (a few seconds). Is there any way to prevent or delay sample decomposition for FTIR analysis? If I can't use this method to analyze my sample, what other method do you suggest?
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Thank you all for the guidance and putting me on the right way.
I wish you the bests.
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I study on some kind of infrared barrier and I don't know how to calculate normalized reflectance spectra weighted by human body radiation?
For example you can see results of this article but authors did not mention the calculation method:
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Hi everyone, i have work using paracetamol sample with electrochemical wastewater treatment under special conditions, then analyze with COD (Chemical Oxygen Demand) removal, UV and FTIR.
Analyze by the COD removal, the COD removal is high which were up to 70%. The UV spectra shows that the UV peak were reducing between control and treated. But, the FTIR spectra shows that the FTIR of control (untreated Paracetamol) in blue curve and that of treated in purple curve were same like there's no difference. Whereas, based on the COD removal and UV spectra there is a difference. Can anybody tell the reason why the FTIR curve like that? Is it okay if the curve of FTIR like that? "If the the absorbance of the uv peak were reduces, then the transmittance of the FTIR also reduces" is that statement true? The FTIR curve were confusing, so I need your help.
Thanks in advance...
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Does anyone have some good ref talking about how do the FTIR spectra of EDTA change with the formation of Calcium chelate ? Thanks a lot !
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Get your FTIR results analyzed just for $ 20. Check out the link bellow:
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I am using Spectragryph V1.2.15 to visualize FTIR Spectra. But it is showing values in "nm" on x-axis. When i chose the "wavenumber(1/cm)" instead of "nm", it changes the range to 16000-25000. Please suggest where can be the problem?
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What about directly asking the expert on this software (me), who developen it and answers a couple of requests every day? You could even use the Researchgate messaging tool...
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Hello friends,
I am working on RE doped Ferrite materials.
the results comes out for FTIR that there are so many peaks present below 500cm-1.
i know the peaks 600-500 cm-1 represents (M-O) bond. But in my FTIR there are more than 5 peaks are present below 500cm-1. What may be the reason behind this??
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In fact your results seem strange. The additional peaks could be due to impurities present in the sample. Do you have a single phase? Have you verified the phases with X-ray diffraction? Do you collect the spectrum with ATR? In this case the reliable region is up to about 650 cm-1. I think that you should provide more details about your measurement and maybe to show the spectrum
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How significant is the FTIR study of mixed metal oxide photocatalysts like WO3-TiO2 nanocomposites?
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Hi Aarif Shah , in gas phase catalysis FTIR can be quite useful to probe the chemistry of the surface. (In water phase, may be not much will be seen because of water interference, you can perhaps do it, who knows)
If you have a pure metal oxide powder. The FTIR spectra (ATR is preferred) of the powder will already give a few important information about the surface. First, the water molecules that may have from the atmosphere. H2O can adsorb both as molecules, but also in the dissociated form: H and OH. H2O will also be present in the condensed form due to capillary condensation. Now, the dissociated H2O is interesting! Because it denotes a catalytic process. In TiO2, the active sites dissociates the water and then the H and OH are sitting on the active sites. On FTIR a small shoulder at 3596 cm-1 denotes dissociated water for TiO2. Same is observed for ZnO. Around 1600 cm-1 adsorption of molecular water is denoted by a peak. Further absorption bands from the metal oxide itself are difficult to interpret. But things can still be improved because data science is developing as well.
Now if you are investigating the photocatalysis with WO3 and TiO2, then you can study degradation of a surface organic molecule with FTIR. The C-H stretches of long chain organic molecules show strong absorption in the 2800 cm-1 to 3000 cm-1 region. This absorption peak you can monitor during the degradation. During degradation, CO2 peaks will also evolve. In this work, we exploited the FTIR analysis for studying TiO2, WO3, ZnO and CuO. You may find this interesting:
What is also interesting is DRIFT (Diffuse reflectance FTIR). So this is FTIR where you probe the diffusely reflected signal from the sample after IR incidence. For catalysis it is particularly interesting because it gives only the surface chemistry due to reflection based probing. DRIFT cells are accessories that can bought along with normal FTIR set-ups. An in-situ DRIFT cells where vacuum can be created or gas phase reaction can be carried out is an inexpensive but powerful set-up!
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I have dyed jute-cotton blended fiber with onion peel and other tannin-containing mordants. But after FTIR analysis, we could not explain if there was an increase in bond formation due to the use of tannin than the non mordanted.Now is there a better spectroscopic method for better understanding bond formation in dyed sample and are there ways to determine the amount of bond formation in a particular sample?
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FTIR is a very good method of identifying these bonds. For this you need to normalize the two spectra (natural and treated) at the peak near 1500 - 1510 cm-1. Then you'll se the difference between the two samples
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I recently ran an FTIR analysis to identify two unknown microplastics. The result indicates a matching percentage of over 50% with polyethylene for both particles. However, I wonder if these matching percentages are sufficient to report the type of polymer.
what is the matching percentage generally accepted by journals?
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You should consider the correlation as mentioned above. However, libraries such as Perkin Elmer ATR-FTIR shows reliable identification material up to 85%. I'd recommend you to read this article http://www.pelagicos.net/Reprints/2018/Jung_et_al._2018_MarPollBull.pdf
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I performed FTIR analysis of 2 samples: unmodified cellulose nanocrystal (CNC) and carboxylated CNC that was oxidized by using the TEMPO/NaOCl/NaBr oxidation system. Both spectra are shown.
When comparing the unmodified CNC vs. carboxylated CNC, the carboxylated lacks the broad OH band around 3380 cm-1 and has new peaks (that are indicated in red). What could be the reason for the absence of the broad OH band?
I know that it's been reported in the literature that a C=O band close to 1740 cm-1 (which is applicable to my carboxylated sample) is typical for isolated carboxyl groups without hydrogen bonds. In addition, the spectra provide evidence of OH's presence in the sample due to the 1610 cm-1 band of OH scissoring bend.
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To me, the spectrum in the region of 3500-3000 cm-1 shows derivative like artefacts which sould be because of saturation effects or scattering.
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I want to know how to make accurate peak analysis of FTIR results. As an example, I have an absorption band between 700-720 of wave-number, I mean the parabola which makes the peak's shape starts at 700 and ends at 720. Can I consider the results which in the literature report that for example a peak at 700 or 711 relates to the specific functional group? I want to know how much deviation is standard when you want to report that this peak is related to which functional group. What is the standard order of this kind of deviation? I want to know some standards regarding this issue since I found some peaks in my spectrum which have near values to the reported results in literature but they do not have exactly the same reported value. Can someone guide me please? If you can introduce me a quantitative amount for the deviation, I would be thankful.
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Shima Fasahat Accuracy is always assessed by comparison against a known, certified standard. You have to define how close you need/require/want to be near the 'truth'. You also need to look for materials (e.g. from NIST) that satisfy the accuracy parameter you're searching for.
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I want to analyse my protein sample that I have prepared in water (5mg per ml) but in FTIR due to presence the hydroxy and hydroxyl ion peak my protein peak is not visible. What should I do in such case? Is there any other way?
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Dear Navita!
1. Difference spectrum (protein sample minus solvent) may show protein related peaks
2. You can try to increase concentration by evaporating solvent on ATR (this method may not be suitable for some analysis tasks)
Good luck!
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I have synthesized copper oxide nanoparticles by immobilizing onto clay fibers but the in spectral scan UV vis characteristic peak diminishes. but FTIR and XRD showed the characteristic peaks of the metal nanoparticles. Should I rely on UV or FTIR and XRD are better than UV vis for characterization of metal oxide nanoparticles?
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Dear Noor Ul Ain . Yes FTIR and XRD are better than UV-Visible especially because you have salts (Copper Oxide).
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Do you think that a home microwave oven can be used to eliminate moisture from a soil sample for FTIR analysis or XPS? If so, how many minutes should be used for a complete elimination?
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Dear Javier Ernesto Vilaso Cadre,
For elimination of soil moisture, it must be careful about thermal decomposition of organic matter such as carboxylic and phenolic functional groups of the humic acids, fulvic acids and hydrocarbon compounds which are decomposed in 170-300˚C. Moreover, carbon oxidation of the organic matter is occurred in 360-460˚C. Therefore, it is better to het the soil in oven at 100 ˚C for 48 h.
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I have synthesized cerium oxide nanoparticles via hydrolysis method using NaOH. I obtained yellow precipitates at the end of reaction indicating synthesis of cerium oxide nanoparticles. But in UV vis spectral scan showing two small humps around 225 and at 350 nm. The FTIR spectra showed absorbance peak at 664 cm-1. In literature, FTIR peaks of cerium oxide nanoparticles are reported at 476 cm-1 (Ce-O stretching), 556 cm-1 (O-Ce-O) and 668 cm-1 (Ce-O) stretching mode. I also have peaks at 1055 and 1318 cm-1 for nitrate.
Does that indicate reduction wasn't complete?
Or Calcination is necessary for Ce oxide nanoparticles synthesis?
I have attached the UV vis spectrum.
Thanks in advance for your assistance and guidance.
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You write that you obtained cerium nanoparticles by hydrolysis. Then you ask the question the restoration was complete. Not restoration, but hydrolysis was complete? As a result of hydrolysis, you get cerium hydroxide. Therefore, calcination is necessary to remove water and obtain oxide from hydroxide. Hydroxide has no chromophores and therefore will not absorb in the visible spectrum. The best analysis is elemental analysis for cerium. It can be done on an energy dispersive attachment to a scanning microscope.
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I am doing research on natural fiber composites. For composite analysis the tests are as following
1. XRD
2.SEM
3.FTIR
4.DMA
5.DSC
6.TGDTA
7.UTM
8.UV Visible
Is that possible a sample can be use in more than one test?
Please help me
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Yes, you can use the same sample for more techniques, but those techniques should not modify the sample, meaning that those techniques should not be invasive. In your case, you can use the same sample for UV-Vis, XRD, SEM, and FTIR.
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Some data points are above 100 whereas most of them are between 95-99%. I have two questions.
1) How can transmittance percentage go above 100 ? either 0, between 0-100 or 100. How above 100 ?
2) Why in most cases it is just below 100. Why does the sample absorb that much. does it make sense. The samples here are in powder form in SHIMADZU ATR type. Is it okay ? If not how can I solve this problem ?
By the way the sample is epoxy based nanocomposite which was powdered before FTIR analysis.
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@Bongisiwe Zozo No.
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Hi everyone, i have work using electrochemical method. I tested before and after treatment my sample using FTIR and the spectra shown in the "FTIR-2" image, with the blue curve is untreated and the purple curve is treated. In the UV spectra (UV-FTIR2 image) shows that the peak in UV absorbance were reducing between control and treated.
My friend have a spectra that show as in the image "FTIR-1", but in that spectra there are differences before and after the treatment (the transmittance increases). I worked the steps the same as her, the concentration of samples we did was not much different, just different sample.
We can see that in the figures "FTIR-1" and "FTIR-2" shows the identification of the O-H and C=O groups. "If the absorbance of the UV peak were reduces, then the transmittance of the FTIR will increase" isn't it? So, what does the spectra "FTIR-2" mean? Why in "FTIR-2" there is no difference in transmittance while the peak in the UV were reduces? Why in "FTIR-2" the transmittance not increase too?
Thanks in advance...
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Dear Nabillach,
I can't see what detailed FTIR maxima positions are, but I suppose the band with max near 1600cm-1 together with one between 3100 cm-1 and 3700 cm-1 belongs to the H2O spectrum. In this case, the maximum near 1600cm-1 would be rather OH scissoring band of H2O than C=O (may be C=O is overlapping with OH vibrations but rather in the case of sample b in FTIR-1 figure). I don't know the chemical compositions of your samples any way are your samples liquid?
Also, to better compare the spectra (if you have the same concentrations of analyte in both samples), it would be helpful to perform a normalization procedure (using the strongest band maxima - or the one which we assume doesn't change from sample to sample). In the case of FTIR-1 results, the stretching vibrations of H2O perhaps would be appropriate to use - max of the range between 3100 - 3700 cm-1 ).
Also, did you perform the measurement using the same optical length - the same distances of the measuring cuvette- for spectrum A and B in the FTIR-1 case,
because this may be the reason for the different intensities of main bands.
I also suggest cutting out the part of the spectra below 700cm-1(it also looks like one from water absorption, and it's noisy too - which doesn't help in interpretation). And if you do so, it seems the most interesting part of the spectra to interpret is one between 700cm-1 and 1650 cm-1 assuming the CO vibrations are overlapping the OH vibrations.
Good luck!
Maja
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Hello everyone,
Here is my problem, I'm beginning a project where I will create a large database of soil spectra (more than 500 soils). The idea of creating such a database is to be able to describe the agronomic properties of a new soil sample based on this database. To produce this database I have access to an ATR-FTIR only.
Thus my concern is how to deal with the different soil granulometry that I will undoubtedly find between different soils samples.
Indeed because of the ATR technologies, the soil/diamond contact surface will have an impact on the result. Is someone already working on this kind of project, or know about some standardized protocols, or a way to take into account this variability?
Already thanking you about the input you can have about this subject, and I'm looking forward to some interesting discussion about this really interesting topic =).
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Hello everyone and thank you for your input.
Allan Philippe
I was already planning to grind and sieve and technical triplicate, hope this will help.
Thomas Mayerhöfer that's an interesting paper, I was not aware of this, will definitely take this into account when making my database.
Magdalena Król I do not have the possibility to use the transmission technique in my lab.
I think it would be interesting to do both transmission and ATR and see what are the differences and thus the limit of both techniques. Did some of you have already try to compare transmission and ATR spectra with soils samples?
Have a good day!
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Here is my CV. Could you please review it and mention my mistakes. Your effort makes my CV impressive. Please review it and suggest me some suggestions.
Please!
Thank you for your precious time and suggestions in advance.
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Change the format of the CV.
and your CV is suitable for academics not for the Industrial Job.
Since most of your articles are under review you have to wait for a little bit.
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I have the FTIR spectra of some OM samples. I am trying to calculate some peak relationships (1650/2920, 1650/1540 etc.) but I have some doubts. The relationship is the simple ratio between both peaks absorbance? Or something else (integralization)? I couldnt find this information in the most recent articles.
Thank you!
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I do agree with Paul Milham.
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Hi there!
I work with infrared spectroscopy (NIR & FTIR) in the field of food science/food chemistry. I'm looking for collaborators with experience in chemometrics (particularly PLS-R & PLS-DA, but other discriminant methods such as SVM or neural networks would also be great). In particular, I'm after people who would be interested in helping with data analysis & writing up some papers based on data I have collected.
If you are interested & have such experience, please contact me & I would love to discuss with you.
Joel
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you can contact me and Dr Silvio David Rodriguez for possible collaborations.
Regards,
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Transmission-FTIR spectroscopy can be used to analyze analytes in aqueous solutions e.g. Proteins in a formulation. Critical step: In order to correctly analyze the structure of proteins, the buffer solution's spectrum needs to be subtracted from the spectrum of the sample containing proteins. However, due to differences in the amount of water that is present in each sample, the difference spectrum cannot be simply calculated by: Difference Spectrum=Protein Spectrum-Buffer Spectrum.
What is a correct method to calculate the difference spectrum for e.g. algorithm based on least squares? I have looked into many papers and the most frequent answer is that a factor is used in calculating the difference spectrum to ensure that the resulting spectrum has a 0 baseline between 1750-2000 cm-1. But using a factor results in negative peaks in the difference spectrum.
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Sven Delbeck If you used Beer's approximation for calibration (or chemometrics based on Beer's approximation), then I hope you used molar concentrations.
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I have some samples of CuO nanoparticles, but I need to know the correct procedure to analyze the sample on the FTIR-ATR instrument. Also, what range should I expect my peaks to be visible in? 4000 cm−1 to 400 cm−1 or is it less than that?
I have read about KBr pelleting for the sample preparation, but can the analysis be done without it or is there any other way?
For the reference of my instrument, I have Perkin Elmer Spectrum Two.
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CuO absorbs between 150 - 600 cm-1
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What is the procedure to do the FTIR analysis of seeds?
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Dear Rajesh Prakash Guragain,
The seeds powder is usually used for FTIR-ATR analysis. I have attached one article. I hope it would be useful.
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I am a PhD student and am currently working on metabolite profiles of some marine invertebrates.
While analysing some raw data generated from LC-MS, HRMS, NMR and FTIR, I was told by some researchers that these raw data, once submitted to a journal as supporting files, cannot be used further for any other analysis. For each analysis I need to generate the raw data again, otherwise it will be treated as a case of self-plagiarism.
I can see that my raw data has a potential of producing three distinct publications. I can analyse different parts of my raw data differently to present distinct conclusions.
But generating all the raw data again from these analyses, and that too for each publication, does not look sustainable to me. And clubbing all three publications in one also does not seem to be a good option here.
So I would like to know your views on this matter as a researcher and also as an Editor/Reviewer. Also, please share your similar experiences and solutions to it.
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It depends. Much data, for example fisheries records, are published for a given purpose - for example to manage a fishery. Many years after that data was published, it may provide other researchers with other information - for example on understanding "shifting baselines". There are many very good pieces of research using historic datasets. My herbarium vouchers are a form of "data". They are lodged in public Herbaria across Australia. The Herbarium staff make the vouchers, and the associated environmental data, available to researchers around the world. They do not limit the number of times any particular voucher may be used to provide a datapoint in someone's research. Those of us who contribute these data rarely hear about their reuse unless we subscribe to platforms like Bionomia. Over a career collecting environmental data I have much that I may never explore fully. I use platforms like the Atlas of Living Australia's BioCollect platform to host my old datasets. It is possible that one day someone may use the hypersaline lake diatom and physico-chemical data from Australia to develop a "diatom metric" index of water quality for these understudied habitats... or for gnammas, or coastal lagoons...
IAs you know what analyses you plan to subject the dataset to, maybe you would be better served in clubbing a group of papers together that look at the different things you have extracted from the dataset, and then provide the entire group to one journal to publish as a "set".
But I would not like for you to have the opinion that data may only be used once then needs be discarded. What a waste of effort. Well conserved datasets, with excellent metadata relating to the methodologies and data collection, can be valuable into the future, in ways we have no current understandings about.
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Hello dear friends,
I am trying to add our own optical components in the sample compartment region of our Nicolet 380 FTIR. Also, our sample is small, so we need to shrink the size of the beam spot with an iris to avoid signals from the substrate.
Therefore, we want to use a mid IR sensor card to help me find where and how large the light beam is. However, the IR sensor card does not show any color change when I put it in the light path (of course, when the light source is on). The mid IR sensor card we use can detect light in the wavelength range of 5-20 um, the min detectable power density is 0.2 W/cm2.
Did I miss anything here? And do you have any suggestions how I shall detect the beam spot, its position and size?
Any suggestions will be highly appreciated! Thank you in advance!
Best regards,
Ziwei
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In general those cards are designed to work with a continuous beam. Don't forget that the IR beam from an FTIR is modulated and in my experience those cards don't work in an interferometer.
The Al foil approach mentioned above will work well but if this is an ongoing problem why not use a beam condenser? Those optics are designed to condense the beam and put the sample exactly where you get the maximum energy. Both Pike Technologies (https://www.piketech.com/product/ms-beam-condensers/) and Specac (https://www.specac.com/en/products/ftir-acc/transmission/solid/microfocus-beam-condenser) provide them and the 380 is a very common instrument so that there should be no concerns about unusual spectrometer configurations.
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It is worldwide discussed that we are eating and consuming microplastics from differents sources like food, water, and many others products that are affecting our health, but how can we:
1) Find comercial products that contains microplastics in order to evaluate if they are in the product itself or not?
Is it something that I should give a blind shot on many products focusing of course on one kind of product (i.e, bottled water)?
and
2) How can I prepare samples from them in order to compare the microplastics composition between differents brands? (i.e, to be evaluated through FTIR analysis, 13C NMR and TGA/DTG)
I would like to know from your expertise about this subject, and if possible recommend papers to be read.
Thank you in advance,
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Hi,
I am planning to perform FTIR microscopy of brain tissues. I want to know that how slides can be prepared for this purpose. Can H and E stained slides be used or separate slides should be prepared on similar basis as for histology without staining. Later that slides can be stained with H and E stain after getting the peaks.
Please explain is it how we perform the FTIR microscopy and also that FTIR spectroscopy is better option to go for?
Best
Humna
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There is a lot of literature on this subject- but maybe you can start here:
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Hello! I have FTIR data of PVDF films with different treatment. I need to calculate value of beta phase and I have some problems with it. There are wave numbers for different phases: http://pubs.rsc.org/en/content/articlepdf/2017/ra/c7ra01267e
There are peaks of gamma and beta phases at 830 and 840 cm^(-1)In my FTIR data and I want to use other peak to determinate beta. But if in one sample I have good peak of beta 473 cm^(-1), in other sample this peak is very weak but peak at 1275 is very strong. What I need to do?
Thank you
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The paper you cited suggests to use the peak-to-valley height ratio to mesure beta to gamma proportion using the bands at 1275 (beta) and 1234 (gamma).
The peak at 473 cm-1 can be misleading since both phases show a peak in that region (482 gamma, 473 beta), but still should be present. Would you post your spectrum for evaluation?
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I regularly doing ATR-FTIR analysis from several mineral oil and surfactant, lately i discover a strange and unknown peak appear (1000-1300 cm-1) which is not belong to the material absorbance (i'm pretty sure because I have previous measured spectra from the same sample).
In the attachment, I put Fig 1 as the comparison of previous measurement and the current spectra.
I did a background scan and follow with scanning empty sample, and I can get straight line without any obvious noises. (fig 2)
Is there anyone having the same issue or know what happen with the spectra result?
In the other hand, i found this file (Fig 3) appear in my storage folder which I don't know where its coming from.
Is there any relation between this file and the issue in my FTIR spectra?
Kindly advice, thanks!
nb: I use Perkin Elmer FTIR
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The logical thing is to think that the sample has changed (it has reacted, degraded, etc ...) Knowing what sample it is would help to see what may be the cause of this spectrum change ...
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Hello everyone,
I have a problem with FTIR analysis.
I synthesize a solution with a polymer, metal particles, a protein, and DI water. Then, I make particles from this above solution.
I take some FTIR spectra with two type of samples (solid and liquid). The solid results are very good as my expectation (significantly different), but the liquid results are not. The FTIR spectra from the solution sample are quite same.
I do not know why two results is so different. Is there anyone have experience about this problem? Please give me your opinion, comment, or advice.
Thanks a lot.
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Suyash Kumar For opaque samples, usually external or internal reflection specctroscopy (the latter is usually termed attenuated total reflection spectroscopy) is employed. The former spectra seem to be more complex to evaluate, but recently we devised a simplified method: I hope this helps!
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I am planning to use ATR-FTIR to find polymer type of microplastic sample.
it is hard to place sample that is very small (1 mm) in the red spot.
Therefore, I am planning to place the sample while it is in the glass filter paper.
But what should be the background reading for the ATR-FTIR to calibrate the sample?
Should it while nothing is there, or with clean glass filter?
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Dear Hamza Shaikh , dealing with tiny microplastic samples can make handling complicated, specially for ATR, however, this is possible with the help of some optical magnification and appropriate handling tools (micro-tweezers, micro-manipulators, etc). Remember how an ATR works. ATR means Attenuated Total Reflection, so if you are using your filter paper as a holder for your samples and to help you to place the microsample it means you will have the filter paper in close contact with the ATR diamond prism, and the microplastic on top of it, so far from the laser beam (separated by the paper thickness). Depending on this thickness and the laser wavelength some light could reach your microplastic sample, but clearly a lot less than placing the microplastic sample directly on top of the prism. Furthermore, you will get a lot more background from the filter paper.
It is true that you could place the filter paper with the microplastic samples upside down, so that the microplastic particles touch the prism. In this way you could enhance the signal from your sample, but still some background from the paper would appear (because your particle is smaller than the prism slit or because the microplastic leaves some light to reach the paper). Of course you can substract the paper´s background as Guzmán Carissimi pointed, but I think that the original recomendation by Thomas Mayerhöfer is the best option.
Alternatively you might find useful to rely on a FTIR microscope, where sample positioning is not so dependent of the particle size.
Another interesting technique could be the use of a Raman microscope, where once more you could focus the laser spot on any particle of interest.
Those microscopic techniques can be applied to "large" areas by means of a scanning option available in modern equipment. In this way you could discriminate different microplastic particles by their chemical composition.
Hope this helps. Good luck with your research work. Best!
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I have had FTIR done on my sample of mesoporous silica nanoparticles coated with chitosan. When I received the data I noticed that all the %transmittance values corresponding to the wavenumber (cm-1) are greater than 100. But how can %tranmittance be greater than 100? Logically the maximum value can be 100 whereas the maximum value in my data is around 125. Can someone kindly explain the reason?
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Unfortunately, instruments may show some drift which means that the reference spectrum should be recorded newly every once in a while. A baseline correction is certainly possible, but the drift is not necessarily constant with regard to wavenumber. What are you actually using as a reference? Note that in infrared spectrophotometry it is generally not a good idea to measure either an empty or a cuvette filled with the pure solvent as reference...
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From a Bruker spectrometer I get OPUS files (.0 extensions). The files normally would be fed into the OPUS software and a Macro transforms them into .DPT. The transformed files then get uploaded into a database where the data is stored to be analyzed further. My goal is to automate the upload from the spectrometer to the database. Therefore, I won't be able to use the OPUS software anymore.
The idea was to analyze the macro (.mtb) and recreate the logic, but I can't seem to open the macro file in a useful manner, neither can I find useful information on how to convert the OPUS files into .dpt or .txt.
I would be thankful for any help.
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You can read and convert a large variety of the binary Bruker*.0 files with optical spectroscopy software http://Spectragryph.com. It is free for academic use.
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I face a difficulties to identify Paraffinic Mineral oil and PAO base oil, from both of the FTIR spectra shows similar peak and absorbances intensity.
Is there any convenient way to distinguish it?
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Thanks Rolf Wolthuis ! That would be something new for me to learn.
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For date palm leaves, FTIR analysis revealed peaks ranging from 4000 to 2800, one of which is extremely close to 4000. (3982) and transmitted more than 80%. Which of the functional groups represents these peaks?
with a note when plants are exposed to salt stress, some of these peaks disappear.
Thank you to everyone who can help.
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3600 peak is due to O-H bonding (non H bonded)
3000 to 3500 peak is due to O-H bonding (H bonded)
3300 peak is due to N-H bonding and also alkynes
3000 peak is due to C-H bonding
Usually, the Single bond region especially Hydrogen bonds lies between the wavenumbers 2500 to 4000.
The peaks will be sharp with strong intensity (Alkyne based)
The peaks will be broad with strong intensity (Alcohol based)
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Hello, if I perform an FTIR analysis of a polymer mixture in brine? I can still determine whether there is an interaction between polymers? For instance, an ftir analysis for HPAM and Xanthan gum in brine. Can you still determine if a hydrogen bond exists between the polymers in brine? thank you
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Yes, one can.
For films or melts I would prefer IR spectroscopy, for solutions (solvent and solute) I would try Raman spectroscopy, if the solvent absorbs to much of the IR signal.
Of course, you might also see interactions between your polymers and the solvent.
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The figure shows the FTIR analysis for Plastic bag sample after three months of incubation with a fungal strain under special conditions. As demonstrated all T% at wave lengths in orange labels refer to standard FTIR polyolefins specifically LDPE as stated by Wiley Spectra Base (2020) in http://spectrabase.com/spectrum/IWxs9GBuNp. The other minor dips appearing in the carbonyl and double bond region blue labeled, and those in the finger-print region labeled in green were confusing, so please I need your help. FTIR of control (untreated Plastic bag) in red curve and that of treated in blue curve.
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Dear Ahmed,
The treated sample FTIR peak and control sample FTIT seem to be the same and the only differences between them is the amount of transmitance%. In this situation there would be no change in chemical structure of the main sample or if there is, it might be negligible. To be sure about it, it is necessary to make a comparision between the ratio of all FTIR peaks of control and treated samples. For example, the ratio of %T of control sample to the treated sample at 2915, 2848, 1467, 876, and 717 must be calculated. If the difference between all of them is meaningful, so it is acceptable to consider change in chemical structure during treating. Otherwise, it is not possible to consider that its chemical structure was changed.
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hello every one.
how i read the FTIR curves to check if there is any reaction occurs between liquid- liquid two phase extraction if i have polymer-salt system (PEG-K2HPO4-water) and small amount of antibiotics ?
if there is any paper related to this topics please upload it here.
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The attached paper may help you.
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This preprint compares the most advanced automated commercial analysis approaches for vibrational spectroscopy including Bruker Lumos II in combination with Purency Microplastics Finder R2021a (FPA-FTIR), Agilent 8700 LDIR (QCL) in combination with Clarity, and WITec alpha300 R in combination with Particle Scout.
Its really worth reading.
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Thanks for sharing
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Dear more experienced colleagues,
I do external reflection FTIR measurement of waxes on a polyethylene substrate (ski waxes on UHMWPE ski base). I'm wondering why peaks associated with for example C-F stretching peaks in case of fluorinated wax, or Si-O-Si and Si-C peaks in case of silicone-based wax do not have the derivative-like shape (as clearly seen for C-H peaks in the spectra), which is associated with the surface reflection. The shape has rather transmission/absorbtion-like shape, but is pointing up towards higher reflectance and not down, as would be the case if the IR light would be reflected from the PE substrate (which is not expected due to the similar refractive indexes of the waxes and the PE substrate). What is the physical explanation of such behaviour?
Thank you for any help!
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Hi Daniel,
the shape of the peaks in a specular reflectance spectrum depends on the oscillator strength. For peaks with comparably weak strengths, like those in organic and biologic matter, the absorption index function is also comparably weak, therefore reflection is dominantly influenced by the real refractive index function and the peaks have a derivative-like shape. For inorganic materials the oscillator strengths can be much higher and the same is true for the absorption index function, which increasingly influences the reflection spectrum until it dominates. Therefore the bands of oscillators with high strength are absorption index-like. If you want to learn more, check out my lecture notes:
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I had synthesized MIL-101(Cr) and performed batch kinetics study with dyes. After the kinetics study, I had dried the samples and performed FTIR studies and got a new peak at 2360 cm-1. I couldn't find a group which had a peak at this wavenumber. Could you please help me in understanding what does this peak corresponds to?
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Hi Saif, the most appropriate answer is Thoma's answer. This peak is assigned to CO2.
Best regards
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Hello everyone,
FTIR analysis of proteins is possible in both solution and in dried microbial cells. I am interested in the effect of concentrated salt solutions (> 1M NaCl/KCl) on the stability of proteome and usually work with cell lysates. Since FTIR allows monitoring of secondary structure (and comparison between various conditions), I wonder if it could be used with cell lysates (hence, complex solutions of proteins).
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May be possible by advanced scientific method.
Name of sample..?
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I'm trying to synthesize a Fe-based metal organic framework but I got something that i guess is Fe3O4, with comparison through pxrd, ftir, and being magnetic of course,
has anyone similar experience??
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Dear Naime, thank you again for your very interesting technical question. Just in case thatcthis is still of interest to you: There are also some more recent reports showing that Fe3O4 can be incorporated into metal-organic frameworks (MOFs) to give some kind of magnetic nanocomposites. For more information about this please have a look at the following very interesting articles:
Fe3O4@MOF Magnetic Nanocomposites: Synthesis and Applications
Facile synthesis of Fe3O4@MIL-100(Fe) towards enhancing photo-Fenton like degradation of levofloxacin via a synergistic effect between Fe3O4and MIL-100(Fe)
Development of a magnetic core-shell Fe3O4@TA@UiO-66 microsphere for removal of arsenic(III) and antimony(III) from aqueous solution
(see attached pdf file)
Electronic structure modulation with ultrafine Fe3O4 nanoparticles on 2D Ni-based metal-organic framework layers for enhanced oxygen evolution reaction
This article is freely available as public full text on RG.
Good luck with your research and best wishes, Frank Edelmann
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I have coated emulsion through layer bi layer coating technique. after FTIR analysis there is no shift of peak occur in coated and un-coated textile. I want its description or reason behind, there might be no chemical interaction between emulsion and textile , only physical attraction that causes no shift of peak, or what else?
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You used a cotton fabric and coated the surface of the fiber with your L-b-L material and tried to see the interaction via FTIR analysis. However, the diameter of cotton fiber is usually 11-22 micrometers and its surface area is on the order of a fraction of M2/g. With such a low surface area, the information from the interfacial interaction between the fiber and the first monomolecular layer equivalent of the L-b-L material is nearly impossible to observe via FTIR analysis. You need the substrate with the surface area of minimum of several tens, if not hundreds of M2/g surface area to comfortably study the interfacial interaction. Thus, the information you are seeking is at least a few orders if not several orders of magnitude weaker than feasible sample. The majority of the information comes from the bulk cotton fabric and bulk L-b-L layers.
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Dear all,
I encountered some peaks (right above 2000 cm-1 as seen in the picture attached) that I can't explain while analysing my multiwalled carbon nanotubes (MWCNTs) using FTIR, Perkins Elmer via the ATR method. I have conducted the readings on 4 separate occasions with similar results. According to some of the papers I've come across, none of them seem to have observed these peaks (I have attached one of the papers as an example). I've tried diluting the MWCNTs to 1% in water but it didn't appear to help either. Would anyone be able to explain how or why these peaks could be there? I would appreciate any words of advice you may have for me as this is fairly new to me.
Kindly find some of the other details as stated. My MWCNTs were purchased from Sigma Aldrich (Cat. no: 698849) with >98% carbon basis with an O.D. × L 6-13 nm × 2.5-20 μm early last year (Jan 2020). The MWCNTs viewed in the picture was used directly as purchased without any treatment (to serve as a control) and directly loaded onto the designated surface. A scanning range of 4000-400 cm-1 was used with a scan number of 16.
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You must have used a single reflection ATR using diamond as the reflection element. Diamond has three characteristic absorption bands in the 2100-1900 cm-1 range. These bands are mostly compensated when you use usual samples, such as polystyrene, though usually not compensated completel. Because the absorption by your usual sample is so strong, these uncompensated diamond peaks are usually not visible. However, since your sample, MWCNT, has almost no IR absorptions, such uncompensated, weak bands from the ATR element becomes visible. Therefore, you might call those bands as an instrumental artifact.
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Can anyone please share or refer any good video links/notes/ppt/website related to the details of various composition analysis (e.g., XPS, XRF, EDAX etc.) carried out in nano-science & nano-technology? It'll certainly provide knowledge about why and when to use such tools or techniques & for which type of samples (e.g., thin films, powder, liquid etc.).
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If you are new to nano-based analyses. I would recommend you to start with online courses and get an idea about various characterizations. here is the link:
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I have a polypropylene-based polymer in which FTIR analysis showed the presence of peaks attributable to PE. How can I determine if it is a PP/PE blend or a propylene-ethylene copolymer? I can perform TG, DSC, XRD and SEM analysis.
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DSC shows 2 Tg for blend  of homopolymers and generally one in random copolymers.
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A heterogeneous catalyst was synthesized by depositing phosphine capped Au on support.
A fraction of phosphine ligands were removed but it appears that Au-P remains. We wanted to study Au-Au and Au-P bond and what technique is best for the determination of this?
Please suggest to me the methodology
I was wondering,
Can one use X-ray photoelectron spectroscopy, Raman spectroscopy, infrared spectroscopy etc. techniques to probe Au-Au bond Au-P bond?
Thanking you,
Yours,
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Dear Shailendra K. Sharma many thanks for your interesting technical question. Compounds comprising Au-Au bonding interactions are of significant theoretical and practical interest. So-called relativistic effects are particularly prominent in gold chemistry, and especially binuclear gold(I) compounds have been found to exhibit Au-Au "aurophilic" bonding interactions. As described in the useful research article cited below, good methods to study such Au-Au bonds are e.g. Raman and UV-vis spectroscopy. Please have a look at the paper entitled
Au–Au chemical bonding induced by UV irradiation of dinuclear gold(i) complexes: a computational study with experimental evidence
This article has been posted as public full text on RG and can be freely downloaded as pdf file.
Also please see:
Real-Time Observation of Tight Au–Au Bond Formation and Relevant Coherent Motion upon Photoexcitation of [Au(CN)2–] Oligomers
Other useful articles related to this topic can be easily found and accessed using the "Search" function of RG. For example, search for the term "Au-Au bond":
This will provide you with a long list of relevant papers in this area.
Good luck with your research! 👍
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The reason I ask is that we have a sample of pure C and I would like to compare.
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you cannot see C-C in FTIR
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Hi
An plant extract was separated into individual compounds by hplc and uv-vis spectra can be extracted for each individual peak(I'm using DAD) . Furthermore, each peak (fraction) can be collected and another FT-IR ATR spectra could be provided.
How can I identify some of the compounds in my plant extract using this techniques?
Does solvent influence FT-IR spectra (eg. Methanol and 0.1%formic acid)?
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Solvent does influence and peaks will be observed, as Dr. Michael said, you need a solvent blank to identify/separate out your peaks for identification.
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I have some P(VDF-co-TrFE) thin films filled with Barium Titanate nanoparticles. The films were prepared by spin-coating techniques and deposited on ITO substrates. The thickness of the films were around 200-300 nm so it is not possible to detach them. I wonder if I can directly measure them using ATR-FTIR?
I am looking forward to your reply.
Best regards.
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At this layer thickness you might see some interference effects caused by the substrate. Check out this recent question: https://www.researchgate.net/post/What_causes_baselines_in_ATR_spectra
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I have done synthesis of ferric oxide by precipitation method and I have done a FTIR analysis. a peak appeared in ~525 cm-1 while another peak appeared in ~434cm-1 only. what is the meaning of them?
and, why is the peaks are only in foot print region?
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The 525 cm-1 band is due to the Fe-O stretching and 434 cm-1 band is caused by the O-Fe-O bending mode. Since both Fe and O are rather heavy atoms, in particular Fe, the vibrational frequencies of harmonic oscillators that are connected by a single bond is rather small. When you have a light element, the frequency increases dramatically, such as CH stretching mode around 2900 cm-1. The number of the expected absorption modes for any molecules is 3N-6, provided that the molecular symmetry does not prohibit appearance in the spectrum. Thus, the molecule with no symmetry will follow this rule. Those groups that are missing in FTIR spectrum by the molecular symmetry can be observed by Raman spectroscopy.
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And how much does it increase after IR absorption? What is the change in bond length at a natural frequency of vibration and at a given IR energy, for the C=O bond for example?
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In addition to all the interesting answers, your question has a simple explanation in terms of the spring constant from an HO model, Dr. Purvi Kikani
I unquote from the link I provide:
"The spring constant for a single bond is typically around 6.5 eV / Angstrom2, while for a double bond it is twice that" (Kenneth R. Koehler, 2013) CC commons licence.
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I have seen in some articles regarding quantification of spectral data using spectra deconvolution. How can I deconvolute the spectral data using Origin or any specialized program? Can somebody please suggest any relevant reading or tutorial, etc. 
Thanks in advance. 
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Pallab Kumar Borah Deconvolution of a composite peak into its individual peaks plays an important role in the interpretation of many types of graphs including XRD, XPS, FTIR, and PL etc. In this video, I have discussed how to deconvolute simple combined peaks, composite peaks and how to correct missing data in a given peak with the help of deconvolution. In the case you want to further ask about it, please do comment on the specific video, I'll respond to it shortly. I have provided the practice filee (OriginLab) here. Thanks
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Dear all,
During FTIR spectroscopy for pure milk sample and 2000 ppm urea adulterated milk sample, what might be the reason for not getting a significant difference in the absorbance peak in the range of 1500- 2000 cm-1 wavenumber?
Please suggest necessary steps to be undertaken and related papers.
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Because urea has no IR absorption bands in that region that you mentioned. When you spike milk with urea, the two main absorption bands are at ~ 1457 and 1156 cm-1. One more thing, do those spectra belong to the same milk sample, one spiked with urea another not? Try comparing these two spectra after taking the second derivative that will eliminate differences in baseline.
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From FTIR peaks, we can generally calculate the elastic property and the Debye temperature from the Waldron model of a composition.
What else we can calculate aside these calculations?
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Dear Rakibul Hassan , the peaks or bands of a FTIR spectrum provide information about the vibrational modes of chemical groups present on your sample. FTIR is useful to identify new or unknown materials based on their spectra and also to detect contaminants, additives or to detect decomposition products of your material caused by material use or exposure to environmental conditions or working conditions.
The technique is also useful to study structural variations of semicrystalline polymers and to identify polymorphic materials among many other applications.
Hope it helps.
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I want to write a paper on FTIR to describe the Elastic property or (and) something that pertains to the FTIR . Generally, we see the authors introduce XRD in their papers to describe the structure of the compositions. XRD pattern can easily represent the structure of the composition. However, the FTIR peaks also represent the structure of the composition.
So, can I use FTIR instead of XRD in such case?
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Dear Hassan, considering your doubt I believe that FTIR data gives information about the chemical nature of the materials and also some details about interaction. These interactions may offer support to discuss some mechanical properties; however, FTIR is not a quantitative technique, and the analysis history matters. Also, different from XRD, FTIR does not give information about the structure (amorphous, crystallinity, crystal size, etc.). It is common to make an associative discussion correlating FTIR and XRD data. Usually, these techniques give complementary data. Regards, André.
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Using FTIR (Fourier-transform infrared spectroscopy), we analyze composition of our samples containing microplastics ! This technique could give us separated peaks (different absorptions) or we have to purify samples under microscope in order to avoid overlapping ?
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When the total number of different polymers are less than several, observing all at once may be feasible, though not easy. However, if you have IR microscope, it would be lot easier to use IR microscope as the spectrum is more easily identifiable. But, be careful, the industrially produced polymers are not pure. There are a large amount of additives mixed into it. Therefore, even a single polymer microspastic particle, the spectrum does not necessarily agree completely with the pure standard spectrum. Therefore, IR microscope is highly recommended. The advantage of IR microscope is, in addition to simplification of the spectrum observed by limiting the number of polymers to see, you can also observe the color and shape of the micro plastics. Each polymer has its own characteristics and combined with those information, your certainly to identifying the material improves.
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First of all, whether it is possible to identify the presence of water and its amount on the Silicon substrate by using only FT-IR spectroscopy.
Can ATR-FTIR spectroscopy find out the wettability of a corrugated Silicon surface?
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I have conducted an FTIR analysis for my extracted asphaltene but I noticed that the absorbance level in the sample is starting from 40% not 0% which means that every single wavelength was absorbed by the sample for at least 40% , do anyone has any explanation for this ?
Note: the FTIR result is attached
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The homogeneous sample is very important in the absorption ratio
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Hi all,
I am working on mid-IR spectroscopy of donor bound excitons in the Si host. I am using an FTIR spectrometer with InSb detector and + KBr or CaF2 beamsplitter. I apply above-bandgap excitation at 671 nm with power levels up to 40 mW. The donors are ion-implanted and consequently drive-in diffused. I need to observe a PL emission at the vicinity of 3 um, while the next highest transition is at 2.2 um, while donor ionization energy is 2.1 um. I observe a broad emission from 2.3-2.4 um to 3.2 um. This emission possesses multiple peaks but overlapping with each other. The emission at 3 um is barely recognized. There is a temperature and power dependency of emission intensity but not much change for the shape. I want to identify the originating factor for this emission. What should I do? How can I isolate and amplify the desired emission>
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@ Mурат Джан Сарихан, вы имете широкий выброс от 2,3-2,4 мкм до 3,2 мкм. Это излучение имеет несколько пиков, но перекрывает друг друга. Эмиссия на уровне 3 мкм практически не распознается. Интенсивность излучения зависит от температуры и мощности, но форма не сильно меняется. источник этого выброса Что делать? Как я могу выделить и усилить желаемое излучение?
Возможно, источник накачки должен иметь длину волны большую, чем 671 нм. На мой взгляд Вы получите смещение в желаемую область спектра.
Пики должны также переместится. С уважением, Оглуздин В.Е.
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Dear Colleagues
Melanins are heterogeneous polymeric natural pigments and these pigments are widely distributed in nature from bacteria to humans. Today, although the structure of other organic polymers has been enlightened in detail, the structure of melanin polymers has not been elucidated in detail, and these natural biopolymers still remain a mystery. While melanin pigment polymerizes in acidic solutions, it dissolves in alkaline environments, separating into oligomers and monomers. These organic macromolecules are insoluble in organic solvents such as ethanol and methanol, but dissolved by ultrasonic extraction with DMSO (Dimethyl Sulfoxide). Today, melanins are grouped under different subheadings such as eumelanin, pheomelanin, pyomelanin, allomelanin and neuromelanins. As a researcher, I have focused on the production of this pigments for the last four years and I want to illuminate the structure of these mysterious macromolecular pigments with different techniques. Since this organic polymer can be produced very little and is very expensive, its use in industrial areas is not widespread. I have achieved very successful results in melanin pigment production with my new methods and I have managed to increase the yield hundreds of times.
I wonder can we use cryo-electron microscopy techniques to illuminate the structure of these pigments? I want to benefit from the knowledge and experience of expert researchers in this field. I can send melanin pigment to researchers who are interested in the subject. Thank you for your interest and contribution.
Best regards.
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Dear Bayram,
Whether it is possible to solve the structure of your pigment depends on the question whether it polymerizes into a regular pattern or whether the polimerization is in fact a type of aggregation. Cryo-EM needs repetition in order to solve a structure. For example if solving a protein structure it takes 100s of images of the dissolved proteins and because each protein is a copy of the other we can calculate an average map of those images and only after seeing the average we can solve the structure. Therefor it is only possible if your polymerization is regular (e.g. crystaline, nanotube, fiber), but not possible if this is not the case. Stil, it could be worth a try to at least have a look at it with cryo-EM to see if this is the case.
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I have conjugated glycol chitosan with bolton hunters reagent, the FTIR spectra of glycol chitosan and glycol chitosan plus bolton hunters reagent look exactly the same. I need xy data to look into detail any slight difference between the two
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Analysis by origin software
FTIR analysis
Absorption
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I'm characterizing Polymer and Elastomer, Now I need to evaluate the data for the FTIR mapping with software. Is there any open source FTIR data analyzer
Kindly please add link for the FTIR free software
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Free software available for FTIR analysis.
  1. Protea: https://www.protea.ltd.uk/free-ftir-software.html
  2. IRPal: https://irpal.soft112.com/
  3. OriginLab (The trial version is fully functional): https://www.originlab.com/demodownload.aspx
  4. irAnalyze (30-day trial version): https://www.labcognition.com/en/irAnalyze.html
  5. VibSpec: Within VibSpec the program IRIS (Infrared and Raman Interpretation Support) is developed. (After installing the software and registering via email the program can be used 10 days for free):https://www.vibspec.com/html/software_eng.html
  6. ir-spectra (Free demo): http://www.ir-spectra.com/
  7. gnuplotting: http://www.gnuplotti
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I need a Paper for FTIR analysis.
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Dear Ashmal Fatima,
I have attached two articles. I hope they would be useful.
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I'm analysing co-crystal using FTIR. Between the pure drug with no change in wave numbers of samples. Do I still continue to test the other?
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Dear All,
I've been synthesizing Ge nanoparticles using OAm as a solvent/capping agent.
Now I'm in the process of assigning the FTIR peaks of my samples.
I've assigned almost every peak in the original solvent, and the same with the NPs.
While comparing them it appears that the features related to N-H disappear, while a new peak forms at 908 cm-1. Please find a screenshot of the comparison in the attachments.
Now the amine can attach at the same time the Ge NPs from the nitrogen side as well as the double bond, assuming the condition are not right for an hydrogermilation reaction, meaning the only possibility is the attachment from the nitrogen side, this new peak should be related to some H-Cn-N-Ge. Sadly, such a system is not really represented in literature or textbooks, my colleagues couldn't help, and running a DFT calculation is quite outside my capacity. So i have no way to clearly identify the origin of this peak. This is getting a bit frustrating, so, I'm trying to ask the scientific community for collective knowledge. Does any of you have experience or the meaning to unveil the nature of that damn peak?
Thanks in advance for your time
Bruno