ASSESSMENT OF THE SAMPLE HANDLING PROCEDURES IN A LABOR-SAVING METHODFOR THE ANALYSIS OF ORGANOCHLORINE COMPOUNDS IN A LARGE NUMBER OF FISH SAMPLES

A rapid single step clean-up procedure with sulphuric acid oxidation f or lipid removal has been assessed by a step-by-step recovery approach for its performance in the analysis of organochlorinated compounds in large numbers of fish samples (muscle). Recovery decreases are essent ially due to losses by evaporation but their effect is compensated by correction of the recovery factor of tetrabromobenzene that is used as surrogate. Sample grounding with sodium sulphate provides significant higher concentrations than freeze-drying. Soxhlet extraction for 18 h is sufficient to draw most organochlorine compounds from the samples. Repeatability and reproducibility is smaller than the dispersion betw een fish of similar length and age from the same lake for all compound s except alpha-hexachlorocyclohexane. (C) 1998 Elsevier Science B.V. A ll rights reserved.