Determination of mercury in hair: Comparison between gold amalgamation-atomic absorption spectrometry and mass spectrometry

After the washing procedure to minimize the external contamination, from each hair sample two aliquots were taken; the first was used for direct analysis of Hg by TDA-AAS and the second was digested for Hg determination by the ICP-MS. Results indicated that the two data sets were fully comparable (median; TDA-AAS, 475 ng g−1; ICP-MS, 437 ng g−1) and were not statistically different (Mann-Whitney test; p = 0.44). The two techniques presented results with a good coefficient of correlation (r = 0.94) despite different operative ranges and method limits. Both techniques satisfied internal performance requirements and the parameters for method validation resulting sensitive, precise and reliable. Finally, the use of the TDA-AAS can be considered instead of the ICP-MS in hair analysis in order to reduce sample manipulation with minor risk of contamination, less time consuming due to the absence of the digestion step and cheaper analyses.