Sample Preparation - Mercury (Hg) analysis in dimethyl sulfoxide (DMSO)
I am working on developing a method to analyze trace amounts of Hg in DMSO. My proposed specification level is 100 µg/g. I have an ICP-OES, ICP-MS, or CVAAS available for instrumentation. I'm not sure what I should do for sample prep, do you have any ideas?
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admin
Total posts: 529
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If the specification level you mention (100 µg/g) is the concentration of Hg expected in the DMSO, then any of the instruments you have available would be suitable for measuring Hg. For simplicity and robustness, the ICP-OES is likely the best choice. As DMSO is miscible in water, we’d suggest diluting in water as much as possible to minimize matrix effects. If 100 µg/g is expected in pure DMSO, then diluting 100-1000x should be suitable for ICP-OES. The calibration standard for Hg will require some acid for stabilization, and either HNO3 or HCl is acceptable, though be aware that low concentrations of Hg (<100 ppm) can exhibit Hg loss when stored in plastic bottles in an HNO3 matrix (seehttp://inorganicventures.com/mercury-chemical-stability for more information). For this reason, it may be more advantageous to use HCl as the standard matrix, and you could spike HCl into your diluted DMSO samples to ensure matrix matching between calibration standards and samples.
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