ABSTRACT
No analytical result regardless of the accuracy and precision of the procedure can be any better than the quality of the sample submitted for analysis. Therefore, the primary concern of the investigator must be directed to the collection of representative samples and the homogeneity of the air mixtures employed to calibrate both the collection and analytical systems. Human sensory perceptions cannot guide the uninitiated with respect to variations of contaminant concentrations in either space or time. Almost without exception gaseous components are either colorless or are present at such low concentrations as to be effectively colorless. The human sense of smell is notoriously deceptive with respect to concentrations of even highly odoriferous components, and therefore cannot be relied upon for estimating relative quality or uniformity of the ambient atmosphere (2,4-Part 3,7,43,44).
