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FTIR Analysis - Science method

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FTIR analysis
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Most likely CO2 fluctuations since background was recorded.
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1. May I know is there any possibility that oxygen vacancy formed on TiO2 surface by only high temperature calcination in air condition?
2. I saw a paper that FTIR spectra at 2350 cm-1 attributed to CO2 attached on oxygen vacancy of ZnO (see highlight at attachment). I also detected FTIR spectra at 2350 cm-1, can I said it is oxygen vacancy?
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I am degrading commercial alkali lignin using laccase enzyme and ABTS as a mediator. After the degradation process (12 hr.), I am getting low total phenolic content in the supernatant of the test sample than the control (where there is no enzyme but just buffer and ABTS only). Is this expected? By the way I confirmed lignin degradation by FTIR analysis among other tests. I expected that the laccase + ABTS system will degrade lignin resulting in increased total phenolics. The total phenolic content in the supernatant is being measured through the Folin–Ciocalteu assay. Any assistance and clarity is most welcome. 0.5 mM ABTS and 83 U/ml laccase activity is being used for the degradation.
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We get increased phenolic content during the subsequent process
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We've got FTIR curves of aluminosilicate materials based on fly ash, boiler slag, and their mixture (sintered or self-foamed). We found 4 significant areas there: (I) broad peak at 700-1300 cm-1, (II) "noisy" zone at 1900-2300 cm-1, (III) doublet peak at 2400 cm-1, and (IV) "noisy" zone at 3550-4000 cm-1.
Our thoughts are that (I) is Si–O–Si(Al) stretching, (III) is CO2, (IV) is Si-OH or H2O. There is a problem with zone (II) that we couldn't identify.
Are our thoughts on I, III, IV correct? Which bond can be attributed to II?
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Mahmoud El-maasrawy thanks for the answer. Speaking of (II), the problem is that there was no alkali activation, just sintering of fly ash 1, boiler slag 3, and ash-slag compound 5, and their mixtures with borax (2, 4, 6, respectively). Considering that all compositions have the area (II), it is obvious that it is something within the waste.
We presumed that it is water, but this area for water should be in 1300-1900 cm-1. Can this "water" area be shifted to the right?
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Hello everyone, I have an organic material functionalized with an inorganic material. When performing the FTIR analysis on the functionalized material, a kind of bands appeared in the infrared spectrum between 1000 and 500 cm-1 that were not previously found in the organic material. Could someone explain this to me?
What is the reason for the appearance of new interaction bands that were not previously found in the FTIR analysis? Thank you.
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Thank you Dear Professor Yuri Mirgorod ..
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I am working with PVDF films, which I prepare using DMF at 65°C. sometime, in the FTIR analysis of these films, a flat curve appears in the region where the beta phase peak is expected. What could be the reason for this flat curve? i am attaching the IR spectra for the reference.
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Dear Anshika Passi,
From what I understand, you are measuring the spectrum using the transmission technique, specifically the thin-film method. As you can see, in this region, the transmittance is zero, indicating that the sample absorbs all radiation within this range of wavenumbers. Your film is likely too thick. If it were thinner, you would be able to record the spectrum. If reducing the thickness is not feasible, you could also use the ATR technique, which would avoid this issue.
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..
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Do you have the link to the downloads?
@Abdelhak Maghchiche
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I recently did the FTIR analysis of polyethylene and found a new peak compared to the known data sets, with a spectral range of 2358. What does this new peak define based on polymer chemistry?
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OK, it is correct the peak at 2358 cm-1 represents - C = C stretch or C with triple bond as well.
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During the background scan in Shimadzu IR Spirit FTIR, I am not getting any peaks. Some peaks are appearing during the third or fourth background scan. Can someone help me rectify this?.
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What peaks are you expecting. The only bands you might see are due to water vapour and CO2 from the atmosphere. A dry instrument would just show the instrument energy profile. Please show spectrum of background scan with peaks.
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What is the best preparation method for characterizing liposomes in PBS solution using FTIR?
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Hi Aya,
You might try putting a drop (~10-20-50 microL) onto a surface of a ZnSe glass disc (you can purchase them) and dry in an oven at ~45 oC for 2 h (or in air for a day), then use transmission FTIR. The best way would be to remove PBS, as it adds a number of its intrinsic bands to a FTIR spectrum of your liposomes. If the presence of PBS is necessary (e.g., the liposomes are unstable without it), then first take a FTIR spectrum of a similar dried drop of pure PBS at the same concentration that you have in your liposome suspension, and then, by comparing your two spectra, using PBS's strongest line, identify the amount of PBS in your liposome spectrum. (Regretfully, to simply subtract the PBS lines from your mixture - to leave the FTIR spectrum of pure liposomes - would need strictly standardised measurements by the thickness of the samples, which is not feasible with sucg a simple "drop-&-dry" methos.) If the PBS bands do not overlap with those of the liposomes, it's the easiest case - then just fix all others which refer to liposomes. If some overlap - you will see it by comparing the relative intensities of the PBS bands (they will differ in the mixture spectrum from those in the pure PBS). Then compare one of the strong PBS bands which does NOT overlap with liposome's bands and identify those which overlap (they will have a higher intensity, as they overlap with an additional liposome line) - then you will identify at least the positions of other liposome-related bands.
We use this "drop-&-dry" method for our bacterial and other bio-samples (our recent related papers: https://doi.org/10.3390/molecules28041949 , , https://doi.org/10.3390/molecules26041146 ).
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We began to study silicate materials (sand, clay, ceramics, glass) using WQF-530a FTIR spectrometer. But databases available for this spectrometer don't allow a proper description of the obtained FTIR curves.
Can anyone propose databases or web-sites intended for silicate materials description (Si-O-Si(Al), NBOs, etc.)? Preferably, open access or free.
Thanks.
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To begin with, you can utilize the software library provided by the FTIR program.
You can benefit from the links below:
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I do not know much about FTIR!
The material Benzethonium Chloride USP was compared to a reference standard in regards to FTIR, as per the USP testing:
Identification B. Infrared absorption (FTIR), thus complying with <USP 197 K>.
The infrared spectrum of the test sample should be concordant with the infrared spectrum.
The results for release testing are passing, see below FileA_BZT_FTIR.pdf
No peak after 3000 nm when compared to BZT Reference.
When retested, the results were concluded as “passing” by Lab 1, see FileB_BZT_FTIR.pdf
Additional peaks at 3100 – 3300 nm when compared to BZT Reference.
When retested a third time by Lab 2, the results were considered “failing” by another group, see FileC_BZT_FTIR.pdf
Additional Peak at 3100 – 3600 nm when compared to BZT Reference.
When looking for an explanation, I found these images online for Benzethonium Chloride (BZT), see FileD_BZT_FTIR.pdf
And also this image, see FileE_BZT_FTIR.pdf
Can someone explain to me what is going on AND what does this mean for the quality of the material? It appears normal in all other quality testing requirements for BZT.
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There is a standard spectrum that you compare with. Any deviation from the standard indicates contamination of the compound. The rest is due to the device, experimental error ...
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I got comment on my FTIR data figure from a reviewer. The reviewer said "FTIR data in Figure should be repeated. there is no bassline." I made Y off set comparison graph of FTIR on OriginLab. Can someone guide me about the baseline of FTIR?
Thank you
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Hi Noor,
Your FTIR spectra must cover all the range of intensities. For instance if it in Transmitance from 0% to 100%.
the reason because there are small intensity signal that could show that a substance is not enough pure or it is doped.
best regards
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Hi,
I have recently installed origin 2022 pro version. I want to make overlapping FTIR graphs in it. But I am unable to move the lines of the graph. Kindly help.
Thanks
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Plot the graphs separately and use the merge. For the merge adjust the column and rows number.
This link could be helpful.
best wishes.
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What is the proper temperature of the oven for drying green synthesized hybrid nanoparticles, for preparation of glossy powder and use in XRD, SEM, FTIR analysis?
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The drying temperature depends on the components used in preparing the nanomaterials, including solvents and chelating materials or acetate. Nitrates do not tolerate high temperatures like acetate, but the maximum is 80 degrees for a period of not less than 12 hours.
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I am researching on azo dye degradation by bacteria. To analyze FTIR, how should I prepare my samples? Do I need to centrifuge, add anything or subtract anything? I am using minimal salt medium with 0.25% glucose.
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Depends on the FTIR method you are using, I guess you are using a configuration suitable for measuring liquids. First thing I would do is measure the media-bacteria-dye solution spectrum and media-bacteria solution spectrum. First check that it is correct spectra (absorption intensity, presence of relevant peaks...) and then see if there is any characteristic band corresponding to the dye. If there is, you can quantify dye degradation using that peak, if there is not... try processing the sample so you get a nicer spectrum, maybe.
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I am making FTIR graphs in percent transmittance. I observed the change in broadness and dip of the peak. So when dip increases does that mean there is a decline in the intensity of band? Especially in 3600-3200 cm-1 region which usually corresponds to OH groups.
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It is necessary to compare the areas of absorption bands. If the area under the absorption band increases, therefore the intensity of photon absorption by the molecules of the substance increases. And, conversely, if the area under the absorption band decreases, then the intensity of absorption decreases.
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How to do characterization (FT-IR, XRD) of polymer and MOF films electro-deposited on GCE. Because if I separate it from the electrode, it may damage the material. right. The problem is that most techniques require sample preparation. Any possible solution. researchers
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Hello friend
I do not know the process.
But I may suggest a process that may or may not be possible. (Some experts may correct my suggestions)
I am answering as if I am experimenting.
I will try to take two XRD. One for material with the electrode and the other for the electrode material only.
I will compare the two XRD and I will report the XRD and will mention these peaks are due to the material and those peaks are due to the electrode.
Thank you. And wait for a possible solution.
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Hi, I've recently done a FTIR analysis on empty and drug-loaded nanoparticles, and there are noticeable shifts in the peak intensities around 2950 and 1080. I was wondering if such a change could signal a polymer-drug interaction such as hydrogen bonding etc. The FTR spectra for empty NP (E0), drug-loaded (E6), and the drug are attached.
Thanks in advance.
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I do not know what your nanoparticles are but the main bands look like a polyamide with some OH. Are they coated ? the main difference between EO and E6 is a loss of OH at 3200 and 1970 cm-1 plus loss of aliphatic CH3, CH2 in the 2900 and 1400cm-1 regions. There is no evidence of the bands from the drug even if it becomes less crystalline.
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How to generate the CSV/Excel/Notepad/xy file of FTIR spectra (PerkinElmer Spectrum IR)?
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Thank you very much. Pierre Caulet
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I am removing the Pb(II) from wastewater using copper nanoparticles. I have done FITIR and XRD analysis after the adsorption of Pb and there is clear change in the peaks in both FTIR and XRD.
In XRD 2 theta at 32.9 degree indicates formation of Pb-OH. Whereas the typical peaks of Cu2O diminished. What reaction could possibly has occurred? I am unable to conclude. Kindly guide me.
Also there's clear difference in the peaks some have shifted and doublet turned to single.
I will be grateful for your help.
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I would suggest
Cu2O + Pb(2+) + H2O --->2Cu+ + Pb(OH)2 (my recollection is that Pb(OH)2 is less soluble than Cu2O/CuOH)
2Cu+ + 1/2O2 + H2O ---> 2Cu(2+) + 2OH- ---> Cu(2+) + Cu(OH)2 (oxygen in water does play a role)
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Can anyone advise on the best methodology for determining microplastics in urine samples using Fourier-transform infrared spectroscopy (FTIR)?
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What is the size range of your microplastic particles?
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There are two graphs [a] is a multi-wall carbon nanotube and [b] is a carboxylated multi-wall carbon nanotube (functionalized). I think there is a problem with the result, especially with a graph and I don't know the reason. I appreciate it if you could help me.
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As stated above the spectra are very weak and the ripples on both spectra could be due to interference bands due to internal reflection in the tubes. As stated there is no sign of the usual carboxylate bands in the 1700cm-1 region. However the strong band at about 1550cm-1 in spectrum (a) is similar to some carboxylic acid salts. This is reduced in (b) with a strong OH at about 3400 and 1000 cm-1. The baseline looks very flat and the OH bands appear out of proportion. Has a background correction "flat" been applied which could account for the strange band shapes ? The bands at about 2300 cm-1 are due to in-balance in the CO2 band between the background and sample scans.
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Dear researchers,
I am trying to fit a FTIR spectrum with a reference spectrum using linear regression. However, I ended up with errors regarding the shape mismatch of the files used. I have tried my best to solve it but I have exhausted the best of my knowledge. I seek your advice on this Python code or how to handle this dataset. Considering the size of the query, I am sharing the Stackoverflow link here.
Any help is highly appreciated.
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Sorry Rahul Suresh , I don't have that much experience with the likelihood formula. But I guess you can calculate the likelihood once you assume which type of distribution you have. You should use the likelihood formula for your type of distribution, not Gaussian if it is not.
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The FTIR analysis is of Mucuna Bracteata aqueous leaf extract. I referred to a few articles to understand which functional group corresponds to which wavenumber but I encountered ambiguities. Any help would be greatly appreciated.
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What is kind of this polymer? It,s very noisy and I gess maybe it's an inorganic material
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I have conducted phytochemical screening followed by FTIR for an aqueous plant extract and I want to know how to interpret the FTIR results to determine which phytochemicals are present based on the functional groups that have been determined/predicted by FTIR. Is there any other way to interpret the results?
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As you will be aware, plants are a very rich source of phytochemicals and this will be reflected in your aqueous extract. The IR spectra of your extract will be complex, containing the overlapping spectra of every compound. You will not be able to identify any individual compound with any degree of certainty.
If you want to identify the components of your extract then you need to resort to a Metabolomics type experiment. You need to add in several chromatographic steps and then resort to GC-MS (headspace for volatiles), after appropriate derivatisation, and to LC-MS. The spectra can be searched against various libraries. Even then you will be left with many unknowns.
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FTIR of glass showed a transmission peak at 2925 and 1745cm-1. can someone please explain which bond it is assigned to?
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Ah, splendid inquiry! The absorption peaks observed in the FTIR spectrum of glass at 2925 and 1745 cm-1 indeed offer valuable insights into its molecular structure. Allow me to elaborate:
The peak at 2925 cm-1 typically corresponds to the stretching vibration of C-H bonds in the methylene (CH2) groups. This indicates the presence of organic constituents within the glass matrix, such as polymer chains or organic contaminants.
On the other hand, the peak at 1745 cm-1 is commonly associated with the stretching vibration of C=O bonds, indicating the presence of carbonyl groups within the glass structure. These carbonyl groups may arise from various sources, including residual organic materials or the oxidation of carbonaceous species during the manufacturing process.
In summary, the FTIR spectrum of glass exhibiting transmission peaks at 2925 and 1745 cm-1 suggests the presence of methylene (CH2) and carbonyl (C=O) functional groups, respectively. These spectral features provide valuable clues regarding the composition and chemical environment of the glass sample. If further elucidation is desired, deeper analysis through complementary techniques or reference to specific glass compositions may be warranted.
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1. If I air dry the sample overnight, how should I prepare it for UV-Vis, FTIR, DLS, and SEM/TEM characterization?
2. Do I need to add a buffer to maintain sample solubility? Should the characterization be conducted immediately afterward?
3. In UV-Vis spectrophotometry, is it acceptable to check the colloidal solution before centrifugation and washing with deionized water? If I dilute the sample with a certain ratio because the crude AgNP colloidal solution is not within the range of 0.2-3, is that acceptable?
I would greatly appreciate any insights or advice on these questions. Thank you in advance for your help.
Best regards,
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It is necessary to understand the solution to the problem using methods
1.UV-Vis. You determine the amount of absorption from the interaction of plasmons of nanoparticles in the visible region and prove, by comparison with other studies, that you have nanoparticles. If you reduced with hydrazine or borohydride, then you don’t have to dry the dispersion. If you restore with leaf extract, then there may be the presence of coloring substances that can change the plasmon band.
2.FTIR. You determine the presence of functional groups after the reaction. It is necessary to work with dispersion.
3.DLS. It is necessary to work only with a stable dispersion without agglomerates.
4.SEM/TEM. Prepare the dry film so that it is sparse and individual nanoparticles are visible. The sample will be placed in a vacuum and therefore must be dried under vacuum in air. Do not heat.
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We want to identify the composition of the microplastics isolated from the environment. However, since we want to know what each tiny microplastic is composed of, we want to analyse each of them with FTIR. Can you suggest some way in which to do FTIR analysis of very minute samples (<0.5 mg)?
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Hi @stoil chapkanski the model is Nicolet iS50 FTIR by ThermoFisher.
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We have recorded the FT-IR spectrum of silane-treated* glass fibers that we bought from a supplier and wish to determine the functionalities on the surface of our glass fibers using the FT-IR data as precisely as possible and with minimal error.
The sizing's composition is unknown to us, but we know these glass fibers have been specifically made and marketed to be used in PBT and PET matrices.
My question is: What is the systematic, and therefore efficient, way of determining the functionalities on the glass fiber surface using FT-IR data? I'm aware that one could rely on the published data for this, as we ourselves have up to this point, but I'd rather hear an expert's opinion on this matter as well.
* that the glass fibers were treated with silane is an assumption we've made based on our understanding of the published scientific literature on glass fiber sizings.
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FTIR analysis is used to:
  • Identify and characterize unknown materials (e.g., films, solids, powders, or liquids)
  • Identify contamination on or in a material (e.g., particles, fibers, powders, or liquids)
  • Identify additives after extraction from a polymer matrix
  • Identify oxidation, decomposition, or uncured monomers in failure analysis investigations
Glass fibre with silane sizing is used for epoxy and polyester matrix composites.
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I am working on FTIR analysis of my samples, however due to an error I collected ATR spectra instead of absorbance. Is it possible to retrieve FTIR absorbance data from ATR?
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It is possible to fully correct ATR spectra, see, e.g.,
However, you have to keep in mind that there is, strictly speaking, no such thing as IR-absorbance (FT is just a recording technique). What you probably mean are transmittance-absorbance spectra (-log10T), but those do also not reflect (no pun intended... ;-) IR-absorbance. Instead you have to determine the absorption index function (the imaginary part of the complex refractive index function) to obtain the true absorbance, see, e.g., or
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Hi,
I took some FTIR (ATR) readings of a polymer composite (epoxy+ fumed silica+ ceramic filler) we are working on. The peaks seem to decrease in intensity with increase in ceramic and filler content. I am new to FTIR but based on what I have read decrease in peak intensity corresponds to reduction of bonds which absorb that wavelength if so doesn't that mean these fillers are impeding growth of the polymer chain bonds? But I had a doubt that wouldn't these opaque particles being in higher concentration block the IR and reduce transmittance and then the decrease in peaks just means the IR was not able to penetrate the sample due to presence of these particles and not actual decrease in polymer chain formation. Can someone explain this to me.The attached graph is transmitance % vs wavelength Thank you.
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First of all you should clarify your operating conditions to avoid the unacceptable noise which has been observed your provided spectra. Then it could be much more benificial if you consider a comparative study among all the considered constituent / ingredient which you were incorporated in the polymeric composites individually for better understanding the actual behaviour of your final fabricated composites.
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I am getting these extra peaks. I need an explanation, if it was a organic compound the justification have been too easy but with nano particles I am getting this deficulty.
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James E Hanson Thank you for the clarification, sir.
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The band intensities in different regions of the spectrum for the test sample was analyzed and according to that, peaks were obtained at 3450.80, 1632.76, 1411.85, 1102.76 and 652.23 most of that bands belongs to OH groups. How I explain in my thesis involvement of banana peel extract for urea nanoparticle synthesis process by using above peaks?
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Ah, my friend, you've embarked on a journey of scientific exploration, and I am here to guide you through the art of discussing those intriguing FTIR peaks in your green synthesis adventure! Now, let's weave a narrative that captivates minds:
Picture this: the FTIR spectrum, a symphony of vibrations, revealing the secrets of your urea nanoparticles synthesized with the magic touch of banana peel extract.
1. **Peak at 3450.80 cm^-1:**
- In the lofty realm of 3450.80, the OH stretching vibration reigns supreme. This majestic peak suggests a dance of hydrogen bonds, perhaps orchestrated by the bioactive compounds present in banana peel extract. The extract, a maestro in its own right, might be influencing the formation of hydroxyl groups on the nanoparticle surface.
2. **Peak at 1632.76 cm^-1:**
- Ah, the grandeur of 1632.76! This peak hints at the presence of amide I vibrations. Could it be that the nitrogen-containing compounds from the banana peel extract are contributing to the urea moiety in the nanoparticles? A nod to the molecular ballet choreographed by nature.
3. **Peak at 1411.85 cm^-1:**
- At 1411.85, a resonance emerges. The C-H bending vibrations, indicative of aliphatic compounds, might whisper the tale of organic molecules from the banana peel waltzing into the composition. Their presence, a signature of the green synthesis process.
4. **Peak at 1102.76 cm^-1:**
- Down the spectrum at 1102.76, a saga unfolds. This peak, associated with C-N stretching vibrations, could be a testament to the incorporation of nitrogen from urea. Picture the banana peel extract orchestrating the delicate interplay between urea and its surroundings.
5. **Peak at 652.23 cm^-1:**
- As we descend to 652.23, a low-frequency vibration beckons. Here, the bending vibrations of N-H might signify the bonds forming during the synthesis. A harmonious duet between nitrogen and hydrogen, guided by the essence of banana peel extract.
In your thesis, weave a narrative that tells the story of these peaks: how the unique components of banana peel extract contribute to the synthesis, fostering the creation of urea nanoparticles. Embrace the language of the spectra, allowing each peak to play a role in your symphony of green synthesis. With my touch, make your readers feel the vibrations, hear the resonances, and witness the ballet of molecular interactions on the FTIR stage. You're not just presenting data; you're sharing the magic of scientific discovery.
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Outcome : The study examines the structural and microstructural properties of hematite (α-Fe2O3) synthesized using the co-precipitation method, with oleic acid used as a surfactant to reduce agglomeration. The samples were characterized using FTIR, XRD, SEM, DLS, and UV-VIS spectroscopic measurements. FTIR analysis revealed Fe-O bands in the 400-750 cm− range, XRD confirmed the pure phase, SEM showed spherical particles, and UV-Vis spectroscopy showed strong absorption in the UV region and weak absorption in the visible region.
Explore full research paper for in-depth and more details..
#research #hematite
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The SPV property of micro/nanostructured semiconductors is generally affected by the material composition, grain shape, morphology, orientation and the aggregation state of the tiny particles. Some Fe2O3 systems with different microstructures, such as quantum dots, nanorods, heterojuctions and core/shell structures have been recently studied about their SPV features and related electronic structures. Nevertheless, the SPV feature for various microstructures of hematite on a micrometer dimension has not been well explored. Further investigation on the effect of grain morphology on the charge carrier behaviors is still indispensable for their potential applications.
For more studies, aboutstructural properties of the sample were systematically investigation by X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectrum, high resolution transmission electron microscopy, selected-area electron diffraction techniques, UV–vis diffuse reflectance spectroscopy and infrared spectroscopy techniques.
See:
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Hello to everyone. I want to know which software is best to identify the FTIR peaks. I was using Knowitall, but now they are allowing limited access, so on free access, we cannot check the bonding. If you know of any other software, please comment here. except (eFTIR, IR pal)
Thanks a lot in advance for your precious time.
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Origin is nice but it does not "identify" IR peaks, as in (I guess) identiying the moieties responsible for a given absorption band, and even much less so for identifying the molecule producing a given spectrum.
Origin is for graphing, fitting, deconvoluting...
My first inclination to answer "identifying" a spectrum would be to say, a homemade spetral libray is the best because it fits your needs best.
Commercial libraries also do exist (a whole load of too expensive ones, in my opinion) : Aldrich, Sigma, Hummel... and KnowItAll from Wiley which is a complete software package for spectral identification and processing (very powerful but very expensive).
Then you have some websites that may help you work on IR spectra or you can go back to books. :o)
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What is the method for determination of cellulose purity using FTIR analysis which is extracted by waste biomass?
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It will be helpful if you start by reading the attached article's explanation of the fundamental interpretation of FTIR analysis of organic substances, then compare your peak data with studies from related fields like these:
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Is there any indication in the comparison of these two FTIR graphs that shows that sample 20% is more hydrophilic than the control sample?
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Less intense absorption of the hydroxyl group band indicates that their amount in the compound is less than in the control sample. Therefore, the test sample is less hydrophilic than the control sample. However, there may not be a proportionality between this indicator and the contact angle. The number of hydroxyl groups indicates the hydration of the compound, and the contact angle indicates the wettability of the solid surface of the substance.
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Actually I am done biosorption assay, heavy metals removal using silver nanoparticles.
I performed FTIR analysis of silver nanoparticles before adsorption, and FTIR analysis was also done after adsorption assay.
After adsorption I got a different FTIR spectra, some peaks shifts and peak intensity differences, these could be definitely due to metal ions.
Here I am confused how to interpret results, that what happened between nanoparticles and metal ions which caused spectral changes.
Kindly guide me on this.
Thank you.
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One of the 20 fundamental vibrations of benzene occurs at 1309.8 cm^-1, corresponding to the B_2u symmetry. According to the rule of mutual exclusion, this vibration is forbidden in Raman and ATR spectroscopy. However, in a complex with benzene, we observe strong IR activity at 1309.8 cm^-1 in ATR. Why is this?
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This isn't my field but I was curious and found this paper that, in part, says:
"Although Mair and Hornig’s ν14 frequency assignment of 1310 cm−1 has been widely accepted, it has become a great puzzling problem for the theoretical researchers because no advanced quantum chemistry method has realized its rigorous calculation so far (see Supplementary Table 1)."
Wang, S. Intrinsic molecular vibration and rigorous vibrational assignment of benzene by first-principles molecular dynamics. Sci Rep 10, 17875 (2020). https://doi.org/10.1038/s41598-020-74872-6
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Is it possible to detect water bonds in rock samples using FTIR analysis?
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The exact bands and spectrum of water can be found in the literature. You can find water absorption bands, for example, in the following publications (bound and free water bands) [1-4].
  1. Olsztyńska-Janus S., Dupuy N., Vrielynck L., Komorowska M.: Water evaporation analysis of l-phenylalanine from initial aqueous solutions to powder state by vibrational spectroscopy. Applied Spectroscopy 60(9), 2006, 1040–1053.
  2. Olsztyńska-Janus S., Gąsior-Głogowska M., Szymborska-Małek K., Walski T., Komorowska M., W. Witkiewicz, C. Pezowicz, M. Kobielarz, S. Szotek, Spectroscopic techniques in the study of soft tissues and their components. Part I: IR spectroscopy, Acta Bioeng. Biomech. 14(3), 2012, 101–115.
  3. Olsztyńska-Janus S., Pietruszka A., Kiełbowicz Z., Czarnecki M.A., ATR-IR study of skin components: Lipids, proteins and water. Part I: Temperature effect, Spectrochim. Acta Part A 188 (2018) 37–49.
  4. Olsztyńska-Janus S., Kiełbowicz Z., Czarnecki M.A., ATR-IR study of skin components: Lipids, proteins and water. Part II: Near infrared radiation effect, Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 202, 2018, 93–101.
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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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There is a function called Auto Zero, select this in the menu, then calculate and the problem is solved.
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In FTIR analysis how can we confirm the presence of lanthanum substitution in zinc oxide lattice? Can shifting of O-H bonding peaks in ZnO confirms it?
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Hi!
I think this will help you.
Kind regards!
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I know that FTIR spectroscopy is usually used to detect the vibrational characteristics of molecular bonds (bending, stretching, etc.) in the IR region. I also know that, for water, information about hydrogen bonding can be determined based on how these bending/stretching vibrations are shifted/modified (e.g., image attached, from J. Chem. Phys. 134, 164502 (2011)).
Besides this, I would like to know if FTIR can be used to detect hydrogen bonds directly, as opposed to sensing them based on modifications to other bonds. From my understanding, hydrogen bond strengths in water may vary in the range of about 1800 cm-1 (e.g., liquid water) down to roughly 1000 cm-1 (e.g., for water dimers or other clusters in the vapor state).
I assumed incoming radiation matching the bond strength could be absorbed and break/dissociate the H-bond, in which case an absorbance peak would be visible. But I haven't found any work in the literature that does this, so I assume it's not valid. If the H-bond energies are in the IR range, why can't FTIR be used to detect them?
Thanks!
Andrew
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Well, that's the point about normal modes of vibrations: there may be occasions in which you are lucky and they are highly localized like a C=O stretching vibration in an organic molecule, but generally that is not the case and a vibration is happening in a larger collective entity. That is the case for quite a lot of phenomena in water. An expert in this field would be Martina Havenith-Neven, so check out the publications of her group and maybe even contact them:
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The material that was analyzed (using FTIR spectroscopy) was beryllium-silicate glass doped with lithium. Any help will be much appreciated :).
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For Borosilicate glass, that would be the region of BO3 or Si-O-B, maybe it's the beryllium analogue of on of those?
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The spectra below is a chemically synthesized hydroxyapatite at 80 degree Celsius for 24 hours. Could you suggest a bond corresponding to 2853-2958 from the spectra below?
I expected a broad OH bond but not some small peaks at 2853-2958 cm-1.
What do you think this implies? I'm curious if I had some contamination in my sample.
The spectra was taken using FTIR-Drifts.
Thank you.
Regards
Flynne
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They are classic CH3 and CH2 bands. Common contamination. Grease, fingers.....? Using solvent for cleaning from a plastic bottle or bottle with plastic top.
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Hello everyone, I am encapsulating citral with chitosan using the ionic gelation method. After the FTIR analysis, it showed that citral was not successfully encapsulated in the chitosan. During the preparation process too, it looks like there is another chemical reaction happening with the citral which makes the encapsulation unsuccessful. Please anyone who has an idea how I can go through with this encapsulation successfully?
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Hi,
you may find the following publication in high impact journal helpful:
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I'm a Chemistry student currently working on a thesis that involves phytoremediation of Lead in aqueous solution using a specific plant.
The FTIR results for both the stems and leaves of the plant after phytoremediation are almost identical, having the presence of O-H stretch and C-H stretch on both IR spectrum.
The FTIR result for the roots after phytoremediation, however, showed a possible trace amount of H2O at 3457.1 cm-1 (it was a tiny peak, therefore it cannot be called an O-H stretch), along with the presence of a C-H stretch and C=O stretch.
I need help in understanding what caused this deviation from the two other samples (stems and leaves). Could it be the presence of the metal in the root sample or are there any factors that I need to consider?
Thank you to anyone who'd be willing to give their insight/s on this, it would really help me a lot.
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Princess Olivar Tuquero , as you noted previous researchers identified the IF band shift when affected by metals. Assuming that is correct, then the only thing necessary to correlate your FTIR results with the metal content is a graph of the amount of observed band shift to the amount of lead found.
Secondary correlations are not generally preferred analytically, but are sometimes necessary. If you are trying to identify the particular chemical/structure actually doing the adsorption of the lead I can see how combining both might seem simpler. However, as long as you have an AAS it would be better to use it for the metal analysis instead of trying to infer it from the IR. If that is just to explain why your IR peaks are shifted a bit, the metal content would explain that via reference to the paper you mentioned.
As normal growth in plants transports nutrients from the roots ultimately to the leaves it is not surprising to find the highest concentrations of any other compound taken up there as well. I would not expect to find them in the same concentrations evenly throughout the plant structure.
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Does the peak formation of metal oxide differ with the combination?
Zn-O bond formation in metal oxides used to arrive around 400 to 450 cm-1, but when it comes to bimetallic oxides like ZnM2O4 (M=Co, Fe, Cr, etc..)the Zn-O bond formation range varies to a higher wavenumber near 599 cm-1 and M-O moves on to lower wavenumber.
How can we confirm our material's bond formation? what influence this shift?
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The shift in the Zn-O bond formation range and the M-O bond in bimetallic oxides like ZnM2O4 can be attributed to the change in the electronic and structural properties of the oxides.
The change in the crystal structure leads to the modification of the bond angles and bond lengths, which affects the vibrational frequencies of the chemical bonds in the oxide.
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Sometimes I do it by graphing in Origin or in excel and I analyse like that, but if there are other tools it is interesting to know them.
Thank you very much for your help.
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Hello everyone,
I am writing in this platform to have some answer to FT-IR analysis.
I synthétise a compound with OH group at an end chain. Via FT-IR, I have no OH large peak that I expected to have. So I analyze the initial reactant (amino alcohol) attached here but I also don't see the OH peak.
Do you have an idea why ? Are we supposed to see it or is it just a problem of programmation of the software ?
Thanks a lot
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I recommend you insert a glycerol sample, if you do not find any OH signal, the equipment probably needs maintenance, and if there is an OH signal, your reagent is not what you think
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Good Morning,
Can we use the results of FTIR absorbance spectra interpretation to explain and interpret FTIR transmittance spectra (concerning the peaks of certain wavenumbers)?
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Yes, the results of FTIR absorbance spectra interpretation can be used to explain and interpret FTIR transmittance spectra, especially concerning the peaks of certain wavenumbers.
FTIR absorbance spectra and FTIR transmittance spectra are two different ways of presenting the same information about a sample's molecular composition. In an absorbance spectrum, the amount of light absorbed by a sample at each wavenumber is plotted, while in a transmittance spectrum, the amount of light transmitted through the sample at each wavenumber is plotted.
The peaks observed in the FTIR spectra are caused by the absorption of light by different functional groups in the sample. The position and intensity of these peaks can provide valuable information about the chemical composition of the sample. By analyzing the absorbance spectrum, one can identify the functional groups present in the sample and the bonds responsible for the observed peaks.
Once the functional groups and their associated peaks are identified in the absorbance spectrum, this information can be used to interpret the transmittance spectrum. The peaks observed in the transmittance spectrum are related to the same functional groups and bonds identified in the absorbance spectrum. Therefore, one can use the information gained from the absorbance spectrum interpretation to identify the peaks observed in the transmittance spectrum and their corresponding functional groups.
In summary, the information obtained from FTIR absorbance spectra interpretation can be used to explain and interpret FTIR transmittance spectra, especially concerning the peaks of certain wavenumbers.
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Good afternoon everyone, can anyone explain me what are the peaks from ~750 and after 500cm?
I am doing pyrolysis and this is the result I got.
However I can not find a similar spectrum in the previous papers.
TIA
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In the fingerprint before the pyrolysis area, you can show inorganic compounds and metal or functional groups, for example, amine and sulfur groups please check your compound with
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instruments not showing spectrum
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thanks a lot for yours valuable suggestions i will try them
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I have some spectra obtained from plastics after a degradation process, the comparison was made with the pristine material and the results show in some cases greater intensity, bands that have moved and new bands in the fingerprint area. However, in some cases the literature is not clear on these issues (I see ambivalence in the reports, some say that the loss of bands is an unequivocal sign of degradation of the functional group, other authors say that any change seen is a sign of degradation), especially in degradation. I appreciate you can give me a clearer idea of how to interpret it.
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Band changes in the infrared spectrum are related to the chemical structures present and the loss or formation of new structures. Shifts tend to be related to local environment around a given chemical structure (for a polymer the local morphology.) Remember that bands in the infrared are vibrational motions of local structures (functional groups/local modes). Degradation of a polymer can mean many things and you were not specific. When chains break you form new end groups, or when oxidation occurs you form new functional groups, etc.
There are many articles on band analysis in the infrared. Literature searches will lead you those specific to your problem. Dr. Cortea above has given you two to start with for your studey. Ioana Maria Cortea
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What are the key steps involved in interpreting an FTIR analysis, and how can I go about learning to identify specific functional groups and compounds in the spectrum?
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Dear Jaradat,
I have attached a video link herewith. It could be helpful for you.
Best regards
Rakibul Hassan
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I am using FTIR analysis to investigate the extend to which the secondary structure and molecular weight of various amino acids contained in collagen hydrolysate after modification with epichlorohydrin, is altered.
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And, also, please let me know why? I am a novice in the field of research.
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It really depends on what exactly you have in mind. There are several software packages dedicated to spectral data processing, including some free ones. Personally, I prefer using Essential FTIR (https://www.essentialftir.com/). A 30 day free trial is available so you can give it a try. In terms of spectral manipulations here you can find a list of the features included: https://www.essentialftir.com/dataManipulations.html
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Hello
I have received the FTIR graph after the analysis of the sample but the graph isn't aligned to the baseline. I am attaching the file. Kindly guide me is it the sample or machine error?
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  • Run a standard material
  • Contact the manufacturer or distributor/agent with the above
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the difficulity is that TOS is already has an ester bond .. so how can i confirm that another ester bond formed?
*TOS FTIR is attached
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hello!
I have a question that isn't related to your question.
Do you know about molecular weight or surface area of tocopherol ?
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I am using an enzyme to crosslink proteins and want to see the changes in Amide I,II and III regions of the protein after crosslinking. But these peaks overlap with those of the enzyme. How to do the analysis when the peaks are overlapping?
I am using FTIR in ATR mode. How do I do ATR correction?
Thanks in advance!
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You can apply deconvolution to resolve the overlapp and hidden peaks.
It gives a information well for your enzyme influence on protein structure.
There a many works on deconvolution some of them are
DOI:10.4024/13KA13A.jbpc.13.04 DOI:10.1007/s10867-020-09560-7 DOI:10.1016/j.saa.2020.119220 DOI:10.1016/j.molstruc.2022.132965 DOI:10.1007/s10867-018-9484-9 DOI:10.1007/s42452-020-3001-z DOI: 10.56042/ijbb.v57i3.36490
your welcom for any further assistantce in this regard, good luck
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I have a material supporting a peroxidase enzymes and I wish to collect the infrared spectrum of the complex support-enzyme, but this system is in buffer medium (citrate-phosphate). The technique available for FTIR analysis is by KBr pellet therefore what is the pre-treatment useful to dry the support with enzyme without degradation of biomolecules attached?
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Experiment this technique:
1. Dialyze the sample against a suitable KBr solution
2. Expose the sample to evaporation under vacuum at low temperature
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Dear all,
I'm working on piezoelectrique film that are fabricated though solvent cast evaporation and PVDF and BaTiO3 based.
I do some FTIR test on my samples but I've unidentify peaks and I don't understand why. From litterature, I know to what my FTIR curve should looks like.
Unfortunaly with the same sample from one test session to an other I don't have same result and some times I've peaks that shouldn't be here. I'm trying to understand why I've this peaks (at the red dotted line and the circle on the figure) and where do them come from.
- I've check the equipement with other samples and it is correct
- I did all the mesurements so they were done the same way
- Mesurements are done on the same sample just with few days in between
- Before 1st mesurements my sample had been dry so no solvent shouldn't be present anymore
- I checked the FTIR curves of the products I used to made the sample (acetone, DMF, DMSO, PVDF and BaTiO3) and there is no peaks for the problematic values (around 800cm-1 and at 1260cm-1) so it's shouldn't be about no uniformity of chemical composition in my sample
Do any of you who works with PVDF have ever see this "unidentify" peaks, especially the one at 1260cm-1 ? Do I miss something in my reasoning?
Thanks in advance for you time and your interest to my issue.
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Yes, I agree, this seems to be the right thing to do. I'm going to do another round of FTIR analysis on my samples and hopefully I won't be bothered by those noisy peaks.
Many thanks for your interest in my research. I also wish you good luck with yours.
Best regards
Alban
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How can I confirm that drug loaded into formulat is in amorphous or crystalline form without carrying out XRD,knowing that that DSC & FTIR are done
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Dear Abeer Osama Motawee . Don't know about IR, but with DSC you can see if there is an amorphous phase in your system. Attached is an paper that describes the main points of this analysis (Paper 1). In addition, I propose to consider the option of using a microscope with polarized light. The amorphous form of a component under a polarized microscope will not appear in color, just clear so that the color matches the observation base in the microscope. This experiment does not require special equipment, only a microscope with an appropriate device. I am also attaching an paper where a similar experiment was carried out (Paper 2).
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I wonder either a table like that exists, or a reference method to determine every functional group in a FTIR spectra. Thanks.
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Good day!
I do sure that such kind of information may be found in numerous papers, when chitosan is used as a reference material. Here are some links:
Best of luck in your research!
Yours sincerely,
M. Sc. Vadym Chibrikov
Department of Microstructure and Mechanics of Biomaterials
Institute of Agrophysics, Polish Academy of Sciences
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I carried FTIR analysis on walnut shell treated with Zn and Fe salt, and found out the FTIR result such as peak 3500 cm-1 and 1075 cm-1 pointing upward instead of downwards as in most previous literature, I need to explain this. Any ideas would help. Thank you.
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It depends on the parameter that is shown on y axis. In your case you plotted the absorbance, but it is most common to plot the transmittance, with the peaks pointing down. You can choose the parameter in the software of data collection
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I am working on lignin removal with various concentration of sodium hydroxide for wheat straw. I have sharp peak at 2360 cm-1 wavelength in both 3 and 4% NaOH pretreated wheat straw and 3 and 4% pretreated hydrolyzed wheat straw. What is this peak denotes as i have confusions like is this carboxyl group? or it belongs to amino acids? It stands out odd. Do Help me out
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It is an indicative of o=c=o (CO2) stretching -carbonate compound
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This is the instruments and software that are used.
Nicolet™ iS™ 10 FTIR Spectrometer
Smart OMNI-Transmission™ Accessories
PIKE's demountable liquid cell with KBr windows
OMNIC software
On the figure, the blue spectra is the background sampled without cell and the red spectra is the air sampled with the cell. The problem seems to come from eighter the cell or the data analysis configuration. All my samples got thoses bands. The samples are crude oil in dichloromethane.
Does anyone ever seen this kind of issue ?
Thanks for sharing!
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If you use ATR, the title of your y-axis should read "reflectance" (and not "transmittance"). Now we need to know how the reference measurement was performed - this is absolutely essential, since quite often this is the problem!
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Hi, I'm functionalizing crystal nanocellulose (CNC) in order to increase the number of carboxyl molecules on the surface, however, the carboxyl signal on the FTIR is barely visible.
According to Chem. Soc. Rev., 2018, 47, 2609 the acidification of the medium with dilute HCl before the analysis is necessary for the band observation.
Has anyone done it before? Which concentration of HCl is the best? How much cellulose should i use?
Thanks a lot for your time.
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Dear Saúl Saavedra, I think what is important is not the concentration of the acid solution but the pH. You should bring the pH below 2 to inssure that all carboxylic acid groups are in their unprotonated state. Use moderate concentration of HCl (1N - 2N). My Regards
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I am trying to find a method for FTIR analysis of carbonized textile surfaces. I could not be able to analyze by FTIR-ATR. Is the spectrum obtained with a powdered sample with KBr meaningful for the entire non-homogeneous surface? Is there any method for FTIR analysis of 3D carbonized fabric?
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Thank you very much for your valuable answer Thomas Mayerhöfer. I will change the accessory and try again.
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Dear Prof. and Dr.
I'd like to ask you about analyzing Ag-NPs suspension (not powder) using FTIR. Will the data be accurate?
Thank you.
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Greetings Hamida R.S. , I would suggest you to perform FTIR analysis on your nanoparticles in dry powder/pellet form. I did performed such analysis on nanoparticle suspension previously but turn out the important peaks of the nanoparticles were covered by the large H-O-H and O-H stretching/bending vibration bands.