MINIMIZING THE RISK OF SOME SYSTEMATIC-ERRORS BY THE USE OF THE SINGLE-VESSEL PRINCIPLE FOR COLD VAPOR ATOMIC-ABSORPTION SPECTROMETRIC DETERMINATION OF MERCURY IN BIOLOGICAL SOLIDS

The suitability of the single vessel principle (performing all steps o f an analytical procedure in one vessel) for cold vapour atomic absorp tion spectrometric determination of mercury in biological solids was e valuated. The single vessel method gave a lower mean blank. level with better precision, hence lower detection limits, as compared to the co nventional method. The determination of total mercury in biological st andard reference materials by the single vessel method also produced s ignificantly higher mercury values and better precision than the conve ntional method. However, the mercury concentrations obtained in certif ied reference materials by the use of both methods were close to the m ean certified values. Moreover, the use of the single vessel method is cost effective, rapid and environment friendly. The use of the single vessel technique is therefore recommended for accurate and reliable d etermination of mercury in biological solids.