You must have measured a control sample and performed a standard addition check to assure that no matrix interferences were present. A useful control sample for hair is the NIES (Japan) Hair SRM.

You next prepare the sample for mercury analysis using a flow-injection mercury vapor generator with a heated cell. You use an electrodeless discharge lamp as the radiation source, letting it warm up for about 10 minutes before beginning the analysis.

You prepare a set of standards, matching the nitric acid concentration in the standards to that of the samples. You note that the baseline is drifting significantly but you are still able to measure the samples and you find no mercury in the samples. You want to confirm these measurements, so you decide to do a quick standard addition measurement. How will you do this?

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