Elemental Analysis - Science method

ICP elemental analysis can be used to determine the presence and concentration of metal analytes in a sample. From the concentrations obtained by ICP-AES, it is possible to calculate the chemical formula of a compound.

Mossbauer spectroscopy may be of assistance in determining the iron oxidation states.

Yes, it does.

See link:

For crystalline compound, XRD is the best, but you don't know this compound has crystallinity region or no

there for you need analysis with Elemental analysis and XRF

second time you know which instrument is the best

What fraction of values below BDL is acceptable.

Why are you making the measurements? The why determines what is acceptable.

If you are concerned about an upper limit, then BDLs are of no concern.

If you are concerned about a lower limit, it will depend upon the nature of your concern.

There is no recommendation. There is no rule of thumb.

You decide from the criteria associated with WHY if you have enough information.

Too many BDLs might mean you need a different technique, but it always returns to WHY.

If , say, a customer wants an answer at each location, use the actual result and note the uncertainty. The result is usually meaningless, because of the high uncertainty.

You should search for information in specialized journals. E.g.:

J. Plant Nutr. Soil Sci. 2020, 183, 705–717 DOI: 10.1002/jpln.201900590 "Bioavailability of macro- and micro-nutrients chemically extracted in acidic soils for wheat"

ZJ

One possibility is to spike both blank and test samples with certain amount of the same item/material which has to be measured and thereby increasing the concentration and detection limit.

Dear Jaliya Ranaweera ,

let me first summarize some facts:

i) 'thin' film containing sulfur (S) on top of gold (Au) layer

ii) S containing film:

S K-edge: 2,47keV

S fluorescence lines:

S K-alpha: 2,3keV

S K-beta: 2,46keV

iii) Au substrate:

among others;

Au M_IIIedge: 2,74keV

Au fluorescence lines:

Au M_IIIN_IV: 2,39keV

Au M_IIIN_V: 2,41keV

Data were taken from J. A. Bearden tables:

https://journals.aps.org/rmp/abstract/10.1103/RevModPhys.39.78

conclusions:

a) The energy position of the S K-beta line is about 50eV above the Au M_IIIN_V line; but due to the limited energy resolution of the detector (assumed to be about 120eV) S K-beta will not be seen in the presence Au M_IIIN_V.

b) The energy position of the S K-alpha line is about 90eV below the Au M_IIIN_IV line; but due to the limited energy resolution of the detector (assumed to be about 120eV) will not be clearly seen in the presence Au M_IIIN_V.

c) thus the Au lines have to be omitted or extremely minimized.

There are two ways to do this.

i) avoiding, that excitation radiation will reach the Au stubstrate

and/or

ii) reduce the excitation energy to below Au M_III-edge energy.

XRF scenario:

In the case of XRF, you have to have x-ray photon excitation energies of above the K-edge energy of sulfur, which is at about 2,47keV. For a significant fluorescence yield you have to go to x-ray tube voltages of well avove 2,47kV, at least some 100V above. However, for the maximum photon energies of such an x-ray spectrum you will have penetration depths in the very low µm regime; thus the x-rays will also hit the Au layer beneath your thin film and will be able to excite the Au M_III core level, when the energies are above 2,74 keV.

SEM-EDX scenario:

In the case of electron excitation one will have sub micron penetration depths for the whole electron scatter cascade, when you deal with quite low primary electron energies^*). The penetration depths of the primary electrons of such a beam is much smaller.

So there is a chance, that you will have only a small fraction of primary electrons, which will be able reach the Au substrate.

If one in addiiton restricts the electron beam voltage to below 2,74keV; there is no possibility to excite the Au M_III fluorescence.

Final conclusion:

a) XRF is, to my opinion, not suitable here, due to the strong S- and Au-peak overlap.

b) SEM-EDX may work, if the electron acceleration voltage is restricted to below 2.74kV (but well above 2,47kV).

*) https://www.globalsino.com/EM/page4795.html

Good luck an

best regards

G.M.

Dear Manpreet Kaur ,

I would not rely on EDS , EDX or EDAX or whatever abbriviation are used.

The reason is that the O-K-alpha has an photon energy of about 525eV.

This means that the escape depth and tghus the information depth of the O K-radiation in the presence of Ni and Co is quite small; only about a very few atomic layers.

The situation for the Ni and Co L-radiation is a bit better but not ideal as well.

So you are quite surface sensitive and thus you will get informations about the surface stoichometry of your sample. Any contamination of your sample surface by adsorption of O containing molecules ( e.g.by O₂ itself or water) will give huge errors in the O concentration estimation relative to Ni and Co.

Hi Wesley Machado You can try this:

Through a pilot scale testing, which you can customize as per your need

Nayad Abdallah

Reconcile elemental analysis for all methods. Determine the mass average. Write a formula, such as water or hydrogen peroxide. You have determined 12% hydrogen and 88% oxygen. Write the unknown formula HxOy. Find the ratio x: y and, resulting in an integer ratio

12/1: 88/16 = 12: 5.5 = 2: 1. Hence, you have identified water, not hydrogen peroxide.

Dear all, if NP's aggregation and/or the dielectric environment are behind such shift, it is good to have a look at the following document. My Regards

Dear Adnan Qadir thank you for this very interesting technical question. In my opinion single-crystals X-ray diffraction data cannot replace classical elemental analysis. Here is the main reason: The X-ray data will give you the exact chemical composition of the compound, but only for the crystal which has been measured. Quite often the bulk material contains only very few well-formed crystals, from which one of them is selected for the X-ray dffraction study. Thus the composition of this single crystal does not tell you anything about the chemical composition of the bulk material. In some cases only a by-product of the reaction crystallizes nicely, while the main product only forms a microcrystalline powder. In other cases the good crystals contain a different amount of solvent of crystallization. Thus when it come to publication of your work please keep in mind that the X-ray diffraction data are not a suitable replacement for elemental analysis.

Can you please reword your question as it does not make sense.

Also check https://pubs.rsc.org/en/content/articlelanding/2018/ja/c7ja00293a

Yes, it is possible, especially in estimating phosphorus and some growth regulators

Dear Muzammil Hussain, If you have the software ChemDraw Ultra , then you can write down the molecular formula or the structure of the compound and the go to analysis window and click it . You will get the elemental analyses well as exact Mass of the compound.sis data . If you don't have it then from standard books you can get the exact average atomic weight of an element up to 4th decimal. Then manually it can be calculated depending on number of each atom present. From it you can calculate the percentage. For your compound it showed the following elemental analyses data as shown by Chemdraw

C₈₀H₄₈N₁₃O₁₂

Exact Mass: 1382.3545

Mol. Wt.: 1383.317

m/e: 1382.3545 (100.0%), 1383.3579 (86.5%), 1384.3612 (37.0%), 1385.3646 (10.4%), 1383.3516 (4.8%), 1384.3549 (4.2%), 1384.3588 (2.5%), 1386.3680 (2.2%), 1385.3621 (2.1%), 1385.3583 (1.8%)

C, 69.46; H, 3.50; N, 13.16; O, 13.88 %

You can verify the purity / authenticity of your sample by comparison with the experimental results

Also check https://chem.libretexts.org/Bookshelves/General_Chemistry/Book%3A_Chemistry_(OpenSTAX)/19%3A_Transition_Metals_and_Coordination_Chemistry/19.1%3A_Properties_of_Transition_Metals_and_Their_Compounds

Also check https://www.hindawi.com/journals/jnm/2019/1703218/

Please look at the following below links which may help you in your analysis.

Thanks

You can use cellulose powder (10% wt/wt) as a binder to prepare pellets from soil samples for X ray fluorescence spectrometry (XRF).

I suggest you look up the archives of the Plasmachem-L ICP discussion board.

https://listserv.syr.edu/scripts/wa.exe?A0=PLASMACHEM-L

There is a search function that should help you out in the first instance, and you can always subscribe and post a question if that doesn't help.

There was a useful thread back in March 2020 about just such an issue.

In general, Iodine and nitric acid don't get on well. Digestions should be alkaline.

With respect to Mass spectra, the mass error should be within 5 ppm (for ESI-HRMS). You can use the following website to calculate or you can do the calculations on your own. Those are simple enough.

https://warwick.ac.uk/fac/sci/chemistry/research/barrow/barrowgroup/calculators/mass_errors Sebastian Oloo

There are many epidemiological studies that confirm the relationship between the contamination of toxic metals in human body and cancerous disease.

If the CHNS analyzer doesn't work properly, you can verify the results by the TOC analyzer or you can check it by EDX analysis.

For otolith, you will probably want to analyse variation of some trace elements (ie. Sr, Ba), which appear to be non-detected or qualitatively detected by EDS ( ). On the other hand, ICPMS will provide your more accurate and consistent results for those elements. Remember that such technique give values for the whole sample, not particular region.

As stated by Esteban, LA-ICPMS stay the gold standard in otolith chemistry analyses, especially for its precise sampling of otolith material (by laser ablation), that provide accurate quantification of trace element in a given region (laser ablation radius is generally around 5-10 um). Hence, you could analyse fine variation along the growth axis, looking for fish ecology, migration or origin.

if i'm right, your structure before calcination contain hydroxyl functions as other function.

since you activated it, you will systematiclly remove oxygen or organic function formed by oxygen atom.

My question for you, is you skeletal stucture contain oxygen also, if you said 'yes' then what you have lost in TGA at 900 °C is attributed to decomposition phenomenon (i don't know the thermal stability of your adsorbant, however 30% it's not decomposition). So i would go with this presumption that the TGA carried out is on the carbone before activation process evenhere i could say it's related to more than just Oxygen. to conclude, 30% and 36% seem to close for me than 11%.

I hope i didn't say somthing wrong.

and i guess you should use Tga coupled to FTIR if you have this technique

Non-conducting specimens for SEM should be coated with conductive material, gold is one of the most common coatings. Looks like operator of your SEM coated specimens with too thick layer of gold and forgot to tell you about it. If possible, coat specimens with carbon. Do not pay attention to amounts of C, O and other light elements in your "quantitative" analysis, they are wrong.

Proper quantification of light elements (such as N) by EDS is a tough task. It requires use of standards and good understanding of the technique. I believe that your results (as well as results from the paper you mentioned) were obtained by means of standarless analysis, which produces huge errors in light elements analysis. If you need bulk analysis of light elements (not a microanalysis, where EDS excels), use other methods, discard EDS results.

There will be data for as many elements as were calibrated. But you need associated QC if you are to rely on the data.

sample is very small to carry out all these analyzes

best regards

https://www.materials-talks.com/blog/2020/01/07/the-basics-of-elemental-analysis-with-xrf-qa/

P.S. Don't tell you boss that I suggested to you to skip the sulfur values... 😂

Please look at the following below attached file which may help you in your issue.

Thanks

First, etch the Al foil surface with suitable solutions.

http://www.freepatentsonline.com/5405493.html

Thank you Hurst and Virgilio for your suggestion, i have tried with 5% HCl with 2% Nitric acid now the recoveries consistent withn in limits.

Is your activated sludge wet or dry? Having said that, even air-dry materials can have a fair proportion of moisture that can alter your results, so drying at low temperature (60-80degC) for 24-48 h might be beneficial for between experiment consistency. If it is wet, then drying might lose a lot of volatile nitrogen compounds which may or may not be part of your analytical interests. (I assume you are not as interested in the fertilizer as much as the residues as nitric acid digests will add plenty of N to your sample).

There are many recipes for digestion procedures out there, but fertilizers might be need particular care as they are relatively concentrated and might react explosively compared to "typical" plant or soil digests.

Clear colourless digest is not as important as completely digested for your purposes: eg silicates will not normally dissolve unless using HF acid which requires specialized fume cupboards and full safety plans in case of spills. If you don't need to analyse for it, don't try to do a complete digest; filter out the lumpy bits and go ahead with the yellowish liquid most digests end up as.

Dear Md.jahirul islam via, the problem has been resolved by following commands

1. convert first sim file to pdb using yasara, then convert the pdb to .gro file in VMD

2. convert trajectories using MD_convert.mcr to xtc file

3. Run the following commands in gromacs (coupled with dssp program)

gmx do_dssp -f egfr.xtc -s egfr.gro -n egfr.ndx -o egfr.xpm - tu ns

(for details of commands visit gromacs manual)

e.g I have used trajectory of P-gp file ,and produced ths figure.

CO2 from limestone (or other carbonates) is included in the loss on ignition, which is usually performed before XRF. However, LOI contains also bound water, e.g. from gypsum or hemihydrate. From XRF alone, determination of limestone is not possible.

You can do a thermogravimetric analysis to quantify CO2. CO2 can also be determined by combustion analysis or by a volumetric method measuring the volume of CO2 released when HCl is added to the cement. The limestone content can then be calculated from the amount of CO2, assuming that dolomite (or other carbonates) is absent, which is often not the case. Calcite can of cause be determined directly by quantitative X-ray diffraction (Rietveld analysis).

Wrong. Carbon tape is a secondary source of C contamination, not really important one.

Hi both of them has their own properties but in our country most of the engineers and researches use finite element method bcz it has been used in mostf of the softwarss and even has been studied more about it.

For example 3 friends of mine in our university are working on subjects that should be used by FEM. But it depends on the subject that you want to study and your guides opinion.

Sure... The segmental molecular weight (Mc) of a crosslinked polymer is conneted to its shear or elastic modulus. In principle, if you can evaluate G' or E' in the rubbery plateau, then the Mc value can be calculated following the formulae:

1) G' = dRT/Mc; and 2) E' = G'/[2(1+nu)], where G' is the shear modulus, E' the elastic modulus, d is the density of your material, R is the gas constant, T is temperature and nu is the poisson ratio.

You will not obtain a a value for the corsslinking density, but an averaged molecular weight between crosslinked segments. Please, remember: when highly crosslinked, smaller Mc values and higher G' and E' values...

SALUT!

Tony (sanchez@hfm.tum.de)

Of course you cannot " choose the elements you expect in your sample to be detected", you'll detect everything (comments above are wrong). If you use carbon or polymer support film, you cannot get rid of C peak. You can decrease/eliminate Cu peak generated by a grid:

- Remove objective aperture during EDS analysis.

- Use top hat aperture

- Use Be (instead of Cu) grid, but it is rather expensive.

XRD and ICP-MS instrumentals are very common. Such Lab facility available in most of the countries.

Your point is valid Bemgba B. Nyakuma for lab analysis of fuel.

I asked for this correlation, because I am trying to make the conversion (proximate-elemental), for a sensor installed on-site in power plant, and I have a simulation model which requires elemental composition, to calculate the required parameters.

I'd suggest to contact Kentgen's group at Radboud University, The Netherlands, or Takegoshi's group at Kyoto University, Japan.

Take a look at:

Umair Riaz thanks

To determine H content you need to perform a HCNS analysis (by elementary analyzer) or H-NMR.

Regards

G

Dear Rodrigo Papai

I am not sure, where your "theory" originates from but as such it is not true that higher mass/charge isotope needs to have a higher sensitivity.

In fact, if you consider that a solution having the same mass concentration (e.g. ug/L) of U with atomic mass of 238 and In with atomic mass of 115 contains more than twice as many In atoms would contratict such a general statement.

As a second fact, quadrupole-based ICPMS usually operate in a way that mass resolving power is increased with mass/charge (leading to similar peak width across the mass/charge range), which theoretically would also favor lower mass/charge sensitivities.

It is a fact that sensitivity in ICPMS generally increases with mass/charge if the heaver ion has similar ionization energy. A significant factor is the so-called space charge effect, which attenuates stronger the transmission lighter ions. A second factor is higher mobility of the lighter ions in the ICP and vacuum interface, causing greater loss by diffusion. The actual sensitivities however depend on a large number of factors like ion optics settings, ICP operating conditions etc. Your data seem to indicata a substantial preferences for lower mass/charge isotopes (Li is twice the limit value) so probably your instrument settings are just not comparable to those used in your "theory".

Dear Sir Zakaria Solaiman

Sorry for late answer. That right ash content should not be avoided and molar ratios should be calculated like say if value of carbon content is 67% then its should be divided with atomic weight of carbon which is 12. In similar way for N, H and O all the % calculated values should be divided with their respective atomic weight and then with theses calculated values ratios should be calculated.

Regards

Amita

Hello Savy Panamkuttiyiel Minal,

The raised topic is interesting. In order to have better visibility, it is necessary to apply a coating with metal nano particles. Most often, the metal coating is made of gold due to its good conductivity and does not react with the biomaterials. Problem remains the size of particles that can change surface roughness because they are not the same size. may even block some openings. That's why the share of metal particles could be best. for analysis. This joints in special conditions with pre-fitted vacuum installations.

Wishing for success in scientific work.

Regards Emil Yankov

If I am understanding your question correctly, then the question doesn't really have an answer. In geopolymer concrete, Si and Al oxides are extensively linked and therefore the Si/Al ratio has a significance in terms of the polymer structure. But in OPC products, the primary structural backbone is C-S-H, wherein SiO2 is the primary counter-cation to CaO and only a small fraction of Si sites are Al-substituted. Other phases not found in geopolymer concrete, notably ettringite and monosulphate, contain a large fraction of the Al.

In OPC chemistry, the Si/Al ratio reflects the ratio of alite and (to a lesser extent) belite to tricalcium aluminate and calcium aluminoferite. Since the alite and (to a lesser extent) belite are the binding phases that are primarily responsible for forming C-S-H and giving OPC products their mechanical and durability properties, increasing the Si/Al ratio will improve all important properties of the OPC. From a perspective of concrete properties, there is no drawback to increasing the Si/Al ratio and, in fact, an "optimal" OPC would have Al content of zero. However, it is not possible to manufacture such OPC for a number of reasons (e.g., raw material availability and the need to form liquid phases of C3A and C4AF in the cement kiln).

Hope this helps!

Dear Agnishwar Girigoswami

That depends a lot on the samples. If the size- (or rather mass-) distribution of metallic particles is well known and there is no significant contribution from dissolved metals of the same type in solution you can estimate the number concentration from the mass concentration of the element(s) determined in the suspension or digestion of the NPs. I would assume that determining the accurate mass distribution is the major challenge for most NP samples/suspensions, because most methods determine a (hydrodynamic) diameter, which is then used to calculate the volume and mass by assuming a sphere. Differences in NP shapes (and/or composition) will thus lead to additional uncertainty in the mass distribution.

You may check the publications for technical details on how the number concentrations were derived. I agree that many publications do not seem to realize how important it is to supply these data.

As opposed to what has been mentioned previously though, particles < 100 nm diameter will usually not differ substantially in their response in ICPOES (or even in ICPMS) when compared to dissolved ions. Using ions in solutions will thus allow for an adequate calibration for such metal-NP suspensions too.

There are numbers of way to solve the problem of values below detection limits, I list some of them:

1- Substitute LOD/2 for all of them.

2- If you want to use the substitution, it is better to substitute LOD/sqrt(2) (to consider for the variance as well).

3- Impute the values below detection limits using multiple imputation.

4- More advance statistical approach is to use the mixture model. A binomial model for below detection limit and a log-normal model for above detection model data.

Hope it helps.

Please look at the following below links which may help you in your analysis:

Thanks

You can use radial view in ICP-OES

Thank you for information, will check these databases! Well, at this stage, the main focus is on Zn, Cu, Pb, Cd, Cr, Mn and macro-elements.

Hi Maria Isabel Varas , here a reference that could help you to do that, But if you need other advice message me and I will send you the protocol we used in our department for low trace elements concentration it usually work for Spinel dissolution. You could also use the Alkali Fusion method with acid digestion (AFAD) method of Senda et al. (2014).

Note with using matrix modifier the furnace temperature program must be changed ashing and atomization temperatures must be increased

Tyler E. Curtis

The elements that would be involved in examples I mentioned would copper, Iron and the compound silica.

Do you think this method could work in some of these cases?

Please look at the following below links which may help you in your analysis:

https://www.collectionscanada.gc.ca/obj/s4/f2/dsk2/ftp01/MQ46005.pdf

Thanks

XPS should serve your purpose with proper sample preparation.

Hello, all depends which exact elements are you interested to analyse and which accuracy you need.

Also remember ICP/MS is destructive.

Here some advantages of all equipments.

The strengths of INAA are:

a. Can analyze a large number of elements simultaneously

b. Very low detection limits for many elements

c. Small sample sizes (1—200 mg)

d. No chemical preparation

e. Non-destructive. The material is available for other analytical techniques.

There are very few limitations. The major limitation is the number of elements that can be analyzed by this technique. Several elements of geological interest, such as Nb, Y and some transition metals, are better determined by other analytical methods. For example, more precise Rb, Sr, Y, Nb, and Zr concentrations can be obtained by x-ray fluorescence (XRF). In fact, INAA and XRF are complimentary techniques and rock and mineral chemistries are often determined using both INAA and XRF. Also, because there is no chemical pre-separation, the sensitivity of the method is dependent upon the sample matrix. For example, detection limits for all elements are lower in tree ring samples than in rock samples.

For ICP/MS all advantages already listed in previous answer.

Only points d,e sometimes point c not available at ICP/MS technique.

Also I am disagree with commercial point - Multi-element method for concurrent determination of virtually all elements of the periodic table.

Practically environmental samples contain all elements in very different concentrations and detection of all elements of periodic system by one analysis In pg/L range impossible, also a lot of problems with detection of some elements with major isotope.

Hope this info will help you.

Good luck!

UV-visible give you info at the time of synthesis. You can differentiate the two using XRD also.

Hi Jorge

I agree it's certainly possible. However, since XRF only detects the Fe content not the O content, the meaured Fe content will not change as a result of its oxidation state: this was the point I was aiming to make.

Kindest Regards

Paul.

Yes, it is possible. Depending on your setup, you can have the TCD of the EA do the measurement before the gas stream passes to the IRMS. That requires the EA software to be synced, so you are running both the EA software and the isotope acquisition software (our setup: Costech + Delta V). If that doesn't work, you can quantify using the peak areas on the IRMS and collect both d13C and TOC simultaneously. Ideally, you want to run all samples at the same dilution setting, but if not, you can adjust for varying dilution settings.

thank you for the answer

1. In the case of substrates, solid means solid state which may contain >15% SS

2. Sludge with the above consistency can be volumetrically measured.

3. 100% solids (i.e. dried) are not used for seeding anaerobic digesters.

4. The fundamental use of substrate is to provide sufficient seeding/microbes to accelerate the anaerobic digestion, process.

As for calculation, if Al was reported on a ww basis,

1 L of measured substrate = Y g

Therefore, the volume of 84 g substrate in L = 1 L x 84 g/Y g

Al mass in mg in 84 g substrate = 145 mg x 84 g/1000 g

Therefore Al concentration in mg/L = Al mass in mg in 84 g substrate ÷ volume of 84 g substrate in L

= 145 mg x 84 g/1000g ÷ 1 L x 84 g/Y g =145 mg x Y/1000/L

In my original answer I provided Al mass in 84 g substrate in mg/L which was wrong because the Al mass in 84 g is 12.18 mg (145 mg x 84 g/1000 g).

Maybe just a platitude: The more similar a standard is to your sample, the more accurate are your results.

Dear Sir

I think the links below will benefit you in your search

Best Regards

Dear Sir. Concerning your issue about the method for multi element analysis of Pb,Sn,Fe,Zn in pure copper on ICP-AES . I think the following below links may help you in your analysis:

https://www.ecn.nl/docs/society/horizontal/hor_desk_19_icp.pdf

http://www.ingentaconnect.com/content/scs/chimia/1994/00000048/00000006/art00010?crawler=true

http://pubs.rsc.org/-/content/articlelanding/1994/ja/ja9940900737#!divAbstract

Thanks

Elementa analysers determine total carbon according to the European Standard 15104:2011.

Therefore you must subtract fixed C to calculate carbon in volatile matter. Fixed C is non volatile.

Check out this site that carries out elemental analysis and describes how the analyser works

You can use BS EN 15104:2011 Standard by CHN instrument.

Also, refer to scientific articles about biomass analysis.

Best Regards