PREVENTION OF CONTAMINATION AND OTHER ACCURACY RISKS IN VOLTAMMETRIC TRACE-METAL ANALYSIS OF NATURAL-WATERS .1. PREPARATORY STEPS, FILTRATION AND STORAGE OF WATER SAMPLES

General and specific contamination factors affecting accuracy of results in heavy metal analysis at the trace level, with particular reference to the determination of Zn, Cd, Pb, Bi and Cu, are evaluated. Precautions are described to achieve a contamination controlled laboratory in general and manipulation places in particular. Pretreatment and cleaning procedures for sampling bottles and other labware, contamination-free filtration of samples and their long-term storage are dealt with. The recommended procedures ensure a satisfactory elimination of contamination and emphasize the significance of the described preparatory steps and precautions during sample handling, to achieve accurate and consequently relevant analytical results, points which have been frequently underestimated in the past. © 1979 Springer-Verlag.