I have solutions from an SFEIS test that I want to check for the dissolved elements. the solution used was Na2SO4 or H2SO4. How much should I dilute the sample before analysis? I am not sure what concentration is expected.
Hi! Explain what the SFEIS test is. Google search does not provide matching data. Do your solutions contain Na2SO4 or H2SO4 or both? In what concentrations? What objects (materials) does this test apply to? How is it performed? Which elements are you interested in and what are their highest concentrations that may appear in your solutions? Are there any specific requirements regarding the quantification limits (not detection limits!) of individual elements in relation to solutions and in relation to the tested objects (materials)? Is the definition of the limit of quantification used standard or some other one? Is it required to provide the estimated uncertainties of the measurement results of the measured concentrations and the uncertainty of the test results? What ICP-OES spectrometer do you have? With radial or axial observation? What are the instrumental detection limits of individual elements in relation to a matrix-free aqueous solution achieved by this spectrometer? Do you have an ultrasonic nebulizer?
Generally, each component of the measured solution, either the test solution or the calibration solution, affects the measurement sensitivity. Therefore, calibration solutions are used that are as similar in matrix as possible to the tested solutions. And also dilute the solutions fed to the spectrometer as much as possible. This means you need to know it in advance or test it yourself experimentally. In your case, it would be best to contact a laboratory that performs such tests on a daily basis and uses ICP-OES (ICP-AES) spectrometry for this purpose. Or maybe your requirements regarding the quality of measurement results could be met by another measurement technique, such as FAAS/FAES? Although this technique is not multi-element and has worse detection limits, it is simpler in implementation and more resistant to matrix effects.
Regards.
ZJ
If you don't know what concentration you have, it is better to go too dilute at first, then work back up until the concentration is within calibration range.
You won't damage anything by running a solution that is near the limit of detection, but you could overload the detector, saturate the system and contaminate the uptake tubing and so on with too much of your sample, particularly off-target elements that you aren't considering but the next user might regard as essential.
Go with dilution in factors of 10: 10-6, 10-5,10-4, 10-3, and see where you start to get a reliable signal. That takes four samples and should get you a good idea of whether you have successfully processed your samples.
Zbigniew Jońca SFEIS stands for single-frequency electrical impedance spectroscopy. it is essentially an electrochemical test that measures the growth of a thin protective oxide film on the exposed surface of a metal. I did these experiments in 0.1M Na2SO4 or H2SO4, not both. I am interested in the metal ions that have dissolved out from this process, namely Fe, Cr, and Al.
The spectrometer we have is a thermofisher icap 6200. I must admit I don't really know enough to know its technical specs without digging for the manual.
Hi! Have you already managed to take measurements without remote advice, or do you still have doubts?
ZJ
- Badges
- Science topic
- Similar topics
- Geoscience
- Atmospheric Sciences
- Climate Science
- Climate Change