Method development for the pre-concentration of mercury in human hair, dogfish liver and dogfish muscle samples using cloud-point extraction and cold vapor atomic absorption spectrometry is demonstrated. Before the extraction, the samples were submitted to microwave-assisted digestion in a mixture of H(2)O(2) and HNO(3). Cloud point extraction was carried out using 0.5% (m/v) ammonium O,O-diethyldithiophosphate (DDTP) as the chelating agent and 0.3% (m/v) Triton X-114 as the non-ionic surfactant. Phase separation was induced after the addition of Na(2)SO(4) to a final concentration of 0.2 mol L(-1). Aliquots of the final extract were transferred to PTFE tubes and NaBH(4) and HCl were added. The mercury vapor was driven to a non-heated quartz tube for measuring the absorbance. The results obtained with salt-induced phase separation were in good agreement with the certified values at a 95% confidence level. An enrichment factor of 10 allowed a detection limit of 0.4 ng g(-1) to be obtained, which demonstrates the high sensitivity of the proposed procedure for the determination of mercury at trace levels.
No takes yet. Share an insight, caveat, or question.
Dittert et al. (2007) studied this question.