Elemental Analysis

Elemental Analysis

  • Atilla Atli added an answer:
    In case of deposited film on any electrode (say graphite), what might be the reasons for not getting any characteristic peaks from Powdr XRD analysis?

    I am getting only the subtrate (electrode) peaks and not the electrodeposited samples peaks although i can see visually the smooth deposition of Ni and Ni(OH)2 onto it. I wonder what are the possibilities of not getting any PXRD peaks although EDAX and other elemental analysis prove its presence. The thickness of the deposition is about ~ 5-6 micrometers (from AFM and SEM cross sectional image).

    Please suggest what might be the case.

    Thank you

    Atilla Atli · École Catholique d'Arts et Métiers

    If you don't have any technical problem (alignment of X-ray beam etc...) one reason would be the amorphous state of deposited film as Marcella and Jean-Aimé told. Other would be the poor signal coming from the film if the thickness is not enough. Another reason would be that the signal from the deposited film overlaps with the signal from the substrate (!). 

  • Ibrar Ahmed asked a question:
    Does anyone know about comparative analysis of elemental composition of various wheat varieties (seeds)?

    I have seeds (limited supply, with less than a gram for some varieties) as the starting material. Please suggest a suitable platform / machine, sample preparation methodology and analyses. Thanks.

  • Xiaowei Zhou asked a question:
    How do I created Hexahedral elements from pyformex for abaqus/cfd?

    Hi all,

    I used the similar method as this video(https://www.youtube.com/watch?v=T1pVFCzrmGI) in pyformex(www.pyFormex.org) to generate the hexahedral elements for my vascular cfd in abaqus. The meshes were very well(very good 8 nodes 3d bricks). Then I exported the meshes to a .inp file with the nodes and elements information. In the .inp file, I set the element type as FC3D8 manually. After that I can import the .inp file in Abaqus/CAE with file-->import-->model. Then I got the orphan mesh in Abaqus/CAE. Everything goes well at this point. But when I use the mesh verify in abaqus/cae to check the meshes. It shows 100% elements with analysis errors.

    I tried to create a job with these meshes and run it. But there was one error popping out, saying "Quadrature Errors in Pressure Poisson Equation - Element(s) severely distorted. Possible diagnostics are: (A) Check the quality of the elements in the mesh to see if they confirm to the element type specified. It is possible that certain elements are interpenetrating or have become degenerate during the mesh generation. "

    I doubt the meshes generated from Pyformex are not compatible with the FC3D8 element type. However, the elements I can see from pyformex are quite well(very nice 8 nodes brick). And the group who developed the pyformex also used abaqus/cfd to do their simulation based on the meshes generated from pyformex.

    I really don't know the reason. If anybody can give me some clues on this issue, I will be very grateful.

    PS. I attached the .inp file and the pictures of the meshes below. 


    Cheers
    Xiaowei

  • Miroslava Sýkorová added an answer:
    How do I perform elemental analysis in metal bhasmas of Ayurveda?

    Atomic absorption spectrometry is used commonly for elemental analysis.Some tests have to be conducted for this where the results are repititive like particle size,molecular structure etc.Which minimal tests have to be conducted which can give maximum results.  

    Miroslava Sýkorová · Comenius University in Bratislava

    X- ray spectrometry is a good technique for multielemental analysis plants and pharmaceuticals. You can use x-ray spectrometry with x-ray tube or radionuclide source.

  • Anjana Acharya added an answer:
    What elements should be used in mesh module for shell analysis subjected to bending in ABAQUS?

    Hi,

    While I am doing a simple shell analysis subjected to bending using linear elements in ABAQUS, the analysis completed without any errors. But while I use quadratic elements, the analysis aborted. I have heard that for bending analysis of shell elements, quadratic elements should be used. But then why the analysis aborted? Meanwhile, I have used static general steps for my analysis.

    Anjana Acharya · Veer Surendra Sai University of Technology

    Palladium can be used  for the quadratic purpose

  • Vladimir Dusevich added an answer:
    How can I subtract background from EDS elemental analysis readings?

    I had my sample tested with EDS elemental analysis. The person in charge of the instrument told me that the results included background which was copper grid and carbon film on the copper grid; I was given the readings of background only as well. However, I am not sure how to subtract background from the sample readings, i.e. to derive the results of just my sample without background values. The two readings are in the file attached with this question. I would be really appreciated of your kind help. Thank you very much in advance.  

    Vladimir Dusevich · University of Missouri - Kansas City

    It is not a background, but spectrum of support film and from stray radiation in TEM. There is no easy way to subtract this "background" . You cannot quantify your current data. The only thing that is obvious from your tables is that Ca, P and O are present in your specimen. You can say nothing about C, Si, Cr, Cu even if some of them are present in your specimen. All other elements are suspicious: you need to verify that their peaks are really present, that they are statistically significant (quantification software is prone to erroneous "identification" of non-present elements) 

  • Laith Najam added an answer:
    Is Black Carbon detected by a CNS elemental analyzer?

    Does the thermal stability of Black (Pyrogenic) Carbon affect the detection by standard CNS Elemental Analysis? As it is stated that this method detects Total Organic Carbon, Black Carbon should be detected asweil.

    Laith Najam · University of Mosul

    yes , Black Carbon can be analyzed by CNS elemental analyzer

  • Marcial Yam added an answer:
    How do you calculate the degree of sulfonation for polymers using CHNS analysis?

    Can anyone tell me what the formula is to calculate the degree of sulfonation for poly(bis phenoxy)phosphozene from CHNS analysis?

    Marcial Yam · Centro de Investigación Científica de Yucatán

    You can calculate with the IEC formula is more direct if you want to calculate with a titration method, or could by NMR only  you need to know structure, positions of the sulfonic groups. 

    wmolecularxMolarConc NaOHxVolume comsumption of NaOH/wsamplex1000-wofsulfonicgroupxMolarConc NaOHxVolume comsumption of NaOH

    and thats it.

  • Maarten A.T.M. Broekmans added an answer:
    Is it natural to have Sulphur in Garnet?

    I have been observing a metamorphic rock that contain Almandine garnet using SEM-EDS. The presence of garnets is confirmed by the very rock's XRD patterns (both Pyrope and Almandine are present).

    Element analysis (SEM-EDS) of various points on Almandine/pyrope shows the following general chemical composition in wt%

    Na - 0 - 1%      K - 0 - 1 %  Al - 17-19%

    Mg - 4 -7 %     Si - 25 - 30%

    Ca - 4 -1 %     (Total)Fe - 30 - 35 %

    Strangely, Sulphur is there ranging 0 to 2%

    Is it natural to have Sulphur in garnet? and are Na, K, Mg and Ca inter exchanging with each other?

    Additional Info (XRF analysis (FP method) shows S element about 1.6 wt%. but XRD does not show any peak for possible Sulphur bearing minerals such as  pyrite or gypsum. Still the rock samples have strong sulphur smell).

    Thank you in advance

    Maarten A.T.M. Broekmans · Norges geologiske undersøkelse

    Dear Tharanga,

    Thanks for your reply.

    I am not surprised that you don't find any pyrite or gypsum by XRD: the amount of pyrite needed to give off a detectable S-signal in microanalysis is MUCH smaller than your XRD lower limit of detection LLD, which is on the order of 1-5wt%, much depending on sample (notably the type of comminution) and specimen preparation of bulk rock powder, as well as its mineral content. (In fact, modal analysis of bulk powder or powdered rock including trace minerals by XRD can be challenging; eg. check literature on Reynold's Cup!)

    Really, by far the most practical method to verify the presence of pyrite inclusions in garnet is optical microscopy, in transmitted light where they will appear opaque, as well as in incident illumination (as suggested by Greg Raab) where they will appear as bright spots if at the surface. Thin- and/or polished-section petrography will also reveal any other S-containing minerals present, which must show up if you report 1.6wt% S by XRF, or alternatively ~4wt% SO3.

    To conclude, I confer with Giovanni Ferraris: chemical analysis alone is INsufficient to determine mineralogy. Imagine you are analyzing carbonate by EPMA and find 56wt% CaO (a very good analysis, even when far short of 100wt%), how would you know whether this would be calcite or aragonite (or vaterite)? The simple answer is: by thin-section petrography, which through optical properties provides information on which polymorph you are looking at.

    Kindest regards,

    Maarten

  • Yafei Wang added an answer:
    Does grinding and polishing influence the detection of elements under EDX?

    EDX is used to determine the elements on sample surface, combined with the observation under SEM. For metals, they are usually grinded or polished before observation. However the preparation process such as grinding by abraisive paper will contaminate the specimen. Accordingly, unexpected elements from abraisive paper such as Si and C could be detected through EDX, which has a bad influence on the results.

    Yafei Wang · Xi'an Jiaotong University

    Hi Yuriy
    You have proposed a very good point in your answer about the inteference of the polishing materials and the elements we are interested in. In other words, choosing the right polishing materials may solve the problem, of course, when there is an option.

    Best regards

    Yafei Wang

  • Marcial Yam added an answer:
    How do I prepare serum samples for the simultaneous determination of heavy metals using AAS?

    Want to perform elemental analysis of blood serum samples but not getting an easy one step method for sample preparation. References provided will be highly appreciated.

    Marcial Yam · Centro de Investigación Científica de Yucatán

    Well I told you, that you need consult methods of digestion dry or wet depending of the extracción, if you use microwave you can use 0.5 g of sample dilued in 25 ml of nitic acid, so you can check any book of standart methods of analysis to ensure he right quantity of nitric acid 

  • Patrick J. Sharrock added an answer:
    How can I calculate elemental weight percent from oxide weight percent given by XRF?

    Hi everyone..I'm running elemental analysis using XRF for carbonated hydroxypatite. I want to find the elemental value of Ca and P. As we know XRF give the analysis in the oxide such e.g CaO . How to obtained the Ca weight percent from the CaO given by the XRF?

    Patrick J. Sharrock · Paul Sabatier University - Toulouse III

    If your EDX machine is working properly, and the operator knows what he is doing, then the elements are listed as % oxides, and can be shown to add up to 100% or not, depending on the particular analysis. However, some elements could be present for example as sulfates of sulfides, or simply not oxides, so a clear image can be obtained if all elements are analyzed and unravelled to give the total elements, and even then, porous products will not add up to 100%, so it can be said that EDX is only a qualitative analysis, chemical analysis is better for getting chemical results that are reliable, and real (EDX could give the result for surface hydrates or hydroxides, that do not reflect the inside composition of any sample). the instruments are also programmed to give you the elements as percentages  directly, so you do not have to worry about converting oxides to elements if that is a problem for you......

  • Rina Singh added an answer:
    What are the techniques / methods to identify metal oxides in a mixture?

    I am working on the catalysts that contain different metal oxides. I want to identify the metal oxides.

    Rina Singh · CSIR Central Road Research Institute

    XPS and FTIR can be used to identify metal oxides.

  • Jinbo Fei added an answer:
    How can I find the type of oxides present and their percentage based on EDX elemental analysis of a surface?

    Element- Weight%- Atomic%

    C - 8.77- 22.56
    O - 15.60- 30.13
    Al - 6.70- 7.67
    Si - 2.18 -2.40
    P -  0.32- 0.32
    S -  0.41 -0.40
    Fe - 66.02- 36.53

    Jinbo Fei · Chinese Academy of Sciences

    Possibly, XPS is the better way to get the precise answer.

  • Vivek Kumar added an answer:
    What are the rules of measuring mass elements in composition?

    Hello everyone, 

    I want to find the percentage of each elements in my thin film, the composition in my thin film is a mix of Al-Cu-Fe. I know,  I can measuring by ICP-MS or XRF. but I have two question:

    1st: Is the percentage for each elements different before and after annealing (temperature is around 800'c) or not?

    2nd: Do you know another methods for measuring the percentages or volumes for each elements (the max error for my composition is less  than 0.1% )?

    Vivek Kumar · Indian Institute of Technology Roorkee

    can anyone provide me the protocol for ICP-MS to quantify the metalloprotein from given sample

  • Julie Perreault added an answer:
    What is the best method for dissolving rocks for ICP-MS?

    Hey Friends

    I need a clear method to dissolve variable rocks to determine elements (main and rare) by ICP-MS  System. 

    could you help me to get this method in clear steps

    thank you very much 

    Julie Perreault · Institut national de la recherche scientifique

    By  grinding your rock, you can perform an alkaline fusion into lithium metaborate 98.5%/ lithium bromide 1.5% flux. We already use this technic on geological sample for rare element.

    0.1g of grind powder in 1g of flux. Perform the fusion into platinum crucible with a fluxer (Claisse Corp.) and recolt it into PFA  beaker with 100ml of acid. (10%HNO3/0.5%HCL)

    We dilute 60 times to reduce the salt into the ICP-MS.

  • Le Zhang added an answer:
    Can someone help me with trace element measurement by SIMS?

    Recently, I used Cameca 1280HR to measure trace elements in basaltic glasses. The accuracy of most elements were +/-1-30%. However, Lu, Hf, Ta and Th (the contents of these elements are about 0.5-5 ppm) had poor accuracy (about 50% or even worse). The peaks of 180Hf and 181Ta were not good and it seemed there were some interferences (maybe 164Dy16O and 165Ho16O). But I don't know how to correct these interferences. The peaks of 175Lu and 232Th were normal. The interferences may be exactly overlaping Lu and 232Th. Could someone give me some advice to improve the accuracy? Thank you very much.

    Le Zhang · Chinese Academy of Sciences

    Hi, Zou, thank you for your information.

  • Bendiba Guedouar added an answer:
    What can WDS-SEM provide in addition to elemental analysis that is available in EDS-SEM?

    EDS: Energy Dispersive Spectroscopy 

    WDS: Wavelength Dispersive Spectroscopy using SEM

    Bendiba Guedouar · Centre Algérien de Développement des Technologies Avancées

    - WDS is second flight especially if you have overlapping peak between Elements
    then in this case the WDS makes distiction
    - WDS is as precise as EDS

  • Yash Gupte added an answer:
    I’m planning to investigate Al and Si co-deposition in silicophytoliths. Can anyone send me information about this subject?

    I am especially interested on papers about elemental anlaysis of silicophytoliths

    Yash Gupte · Ramnarain Ruia College

    diatoms & scanning electron microscope with AAS, dats all u need

  • Simone Cagno added an answer:
    How reliable is energy dispersive X-ray spectroscopy (EDS) for elemental analysis of powder sample?

    Is EDS sufficient to confirm the elemental composition of powder samples (composite) or is it necessary to go for advanced techniques like X-ray fluorescence (XRF) or XPS.

    Simone Cagno · Belgian Nuclear Research Centre

    You could also think of using XRD to identify the mineral/crystalline phases present in your powder

  • Matthew Wheal added an answer:
    Can anyone recommend a standard reference material to use when measuring the total P and Ca in fish tissue using ICP?

    Our goal is to compare whole-body Ca:P ratios between juvenile suckers with deformed opercula and without the deformity and between fish from two Oregon Lakes. I would like to know if deformed opercula that is observed on juvenile suckers and not on other species in UKL is likely to be caused by an imbalance in Ca:P. I would also like to know if the reason that the deformity doesn't occur in Clear Lake is due to a difference in the whole-body Ca:P. 

    Summary of methods: 1) Grind fish in a stainless steel blender (done), 2) ash fish blended fish at 550 C for 16 h, 3) weigh ash, 4) digest ash with HCl and/or HNO3 , 5) dilute with DI water to concentrations within limitation of instrumentation, and 5) use ICP to measure Ca and P.

    I am having a hard time finding a standard reference material of measuring P in animal tissue. I know these measurements are done but no one reports what standards they used. I could use suggestions.  Thank you for your help. 

    Matthew Wheal · Flinders University

    LGC standards list 24 fish materials on their website.

  • Santosh Kumar added an answer:
    How should one treat data with <LOQ values during statistcal analysis?

    I have some data in which a number of the analyte concentrations (data points) obtained were below the quantitation limit (LOQ) of the method used. This is possibly as a result of both the low values of the analytes of intrest expected in the test samples and the method and instrument detection limits. In such a case, how are these "missing" data points treated during statistical analysis and subsequent interpretation and representation?

    Santosh Kumar · Central Electronics Engineering Research Institute

    In Statistical Analysis, If the data is not in our desired way, We have to apply the data preprocessing techniques to form appropriate data.

    Apply different different  preprocessing methods and then analyse them. It will be a better approac and I think It will be very Helpful to You. 

  • Dmitriy Berillo added an answer:
    How can I quantify modified arginine-chitosan without the use of elemental analysis?

    FTIR data is clearly showing modification of polymer, but i need a method for determination of quantification of arginine without use of elemental analysis.. 

    Dmitriy Berillo · Lund University

    Hello,

    I think that the simplest way to estimate a number of arginine in the chitosan is pH metric or conductometric titration of the modified polymer. To be able to do this experiment you will need only pH meter or conductometer. This method works well for linear and even cross-linked polymers.

    Here is a related reference: Metal complexes of amphoteric cryogels based on allylamine and methacrylic acid https://scholar.google.com/scholar?hl=en&q=Metal+complexes+of+amphoteric+cryogels+based+on+allylamine+and+methacrylic+acid&btnG=&as_sdt=1%2C5&as_sdtp=

  • Muhammad Aslam Baig added an answer:
    Can we determine elemental analysis of a material by using femtosecond laser and attosecond lasers as we see in the case of LIBS?

    As we know LIBS is mainly used for the elemental analysis of a material. Is it possible to use femto-second and atto-second lasers? If it is possible then which is a suitable technique and why? Is there any papers related to the elemental analysis by femto-second and atto-second lasers technique? Please give the reference also. Thanks.

    Muhammad Aslam Baig · National Center for Physics, Quaid-i-Azam University, Islamabad

    Nano second and femto second lasers can be used for the LIBS analysis. However, femto second laser are advantageous where surface or craters being produced are used for further studies. The nano second laser are more user friendly and easy to run and maintain.  

    Aslam

  • Tarik Ömer Oğurtani added an answer:
    How do I identify and quantitatively determine the composition of phases present in a composite?

    I have a composite containing oxides of Ni, Zn and P along with their elemental forms. For example, the composite may have the phases Ni2O3+ZnO+P or Ni+ZnO+Zn+P+P2O5 etc. Although EDAX gives the elemental analysis, its very difficult to ascertain whether the %Oxygen obtained is associated with Ni, P or Zn.

    Tarik Ömer Oğurtani · Middle East Technical University

    The powder mixture would be best test sample for the XRD measurements, one can even obtained particle size distribution and the average particle size using fast-Fourier analysis of XRD data, which may be important in the characterization of the final product.

  • Harsh Yadav added an answer:
    Why elemental analysis is not possible with X ray diffraction?

    Why is it that only phase analysis is possible using XRD?

    Harsh Yadav · University of Delhi

    The intensity of the XRD is depend on the structure factor. If you are exactly calculate electron density form its structure factor then you are able to show the exact concern atom belongs the fixed electron density point. The above routine is more accurate in single crystal XRD than powder XRD.

  • Syed Khalid added an answer:
    Which is better technique to detect the presence of 0.2 to 1% Nitrogen in the sample- elemental analysis or EDX analysis?

    Either elemental analysis or EDX analysis is better for identification low percentage nitrogen element. To me no need of quantitative accuracy also. Exact information on either present or not is required.  

    Syed Khalid · Beijing Institute Of Technology

    XRF is the best technique to analyze your sample

  • Jan Gunneweg added an answer:
    What is non-destructive sampling in Cultural Heritage?
    According to my view, even the mere opening of a drawer or a cupboard is already damaging to cultural remains. The shock of opening a drawer, the changing environment between the inside and the outside of a drawer, as well as a sudden light that falls on an artifact that has been in the dark is damaging to any item, especially to parchment, papyrus and paper.

    When it comes to 'taking a sample' needed for applying a analytical technique to an artifact, one can only speak of less and more destructive, because destructive it is.

    For example in Neutron Activation and Petrography, one needs either an amount of 80 mg of pottery powder or a thin-section before submitting the sample either as powder or as a pellet to a nuclear reactor or to a glass slide to be looked at under a microscope.

    I think that the formula "non-destructive sampling technique" was invented by scientists to obtain samples they needed from a curator or conservator. I, therefore, suggest to omit the word "non-destructive" from the Cultural Heritage vocabulary.
    Jan Gunneweg · Hebrew University of Jerusalem

    Andreas, yes you are right that stone can be analysed by using magnifying glasses and portable XRF. Splendid for stone that will not suffer very much by such analyses.

    But what if you do that on parchment or on a drawing? The magnifying glass is not providing the requested information, whereas XRF portable or stable will damage the objects. XRF measured secondary X-Rays that return from an item after having been bombarded by primary X-Rays and the latter--irrespective how large the bombarded area--is not and will not beneficial for the artefact. Whether science has to stop or continue to work with X-Rays or even Gamma-rays is another question.

    I am of the opinion that sometimes--when it is really needed--one must analyze by destructive sampling. Getting results by virtual sampling is as yet impossible, hence my first remark that the term non-destructive sampling is obsolete

About Elemental Analysis

Elemental analysis is a process where a sample of some material (e.g., soil, waste or drinking water, bodily fluids, minerals, chemical compounds) is analyzed for its elemental and sometimes isotopic composition. Elemental analysis can be qualitative (determining what elements are present), and it can be quantitative (determining how much of each are present). Elemental analysis falls within the ambit of analytical chemistry, the set of instruments involved in deciphering the chemical nature of our world.

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