Review Of Contamination Problems In Measuring Trace Elements Revue Des Problemes De Contamination Dans Le Dosage Des Traces

Every sample analyzed must reflect the makeup of the environment in its natural state; contamination hazards, particularly in relation to trace measurements, range from the taking of the sample to the physical or chemical measurement of the content of the particular element being sought. The sources of contamination are many, sometimes built-in or accidental, but nevertheless frequently overlooked. The effects of this on trace measurements are analyzed one by one, and an effort is made to calculate the resulting error; insofar as possible, the best remedy for the situation is suggested. The following factors are studied: sampling, bagging, transport; physical treatment: parting, griding sifting; chemical treatment: acid or alkaline attack, solution; the influence of glassware, equipment, reagents, exposure to air, and handling by personnel. Ordinary practical examples are given to illustrate these sources of error. The main ways of measuring trace elements are reviewed, and the contamination hazards inherent in each are cited.