Sampling Strategy and Direct Solid Sampling Electrothermal Atomization Atomic Absorption Spectrometric Analysis of Trace Elements in Animal Tissue

Abstract

The influence of analyte distribution on analytical results of direct solid sampling and electrothermal atomization atomic absorption spectrometry with direct Zeeman-effect background correction (SS-ZAAS) was studied with the use of nonhomogenized livers of mallards and fallow deer and hierarchic sampling schemes. Significant differences were observed by means of the analysis of variance in lead content of left and right lobes as well as of randomly distributed sampling sites of a deer liver. For the first time SS-ZAAS distribution analysis gave variances dominated by analyte distribution. The distribution analyses of mercury in livers of mallards gave significant effects of sampling sites in 6 out of 10 livers; however, in all cases variance as caused by analyte distribution was observed to be lower than residual variance. Allowing for heterogeneity, the minimal total variance is reached for a given number of replicates when each test sample is taken from a different site of the organ. Despite increased imprecision, the uncertainty of direct solid sampling is thus minimized effectively.