Introduction

Examining tissue residues of environmental contaminants in biota is basic to ecotoxicology, both for understanding the movement of contaminants within organisms and through food chains, and for understanding and quantifying injuries to organisms and their communities. Tissue concentrations have long been used both to identify the cause of toxicity in animals and as a measure of the severity of toxicity. Tissue concentrations of some contaminants are especially challenging to interpret. Concentrations of polycyclic aromatic hydrocarbons, for example, are difficult to interpret in higher animals because they tend to be rapidly metabolized and excreted. The study of tissue concentrations rests entirely on the validity of the chemical analyses supporting them. In general, the ability of today’s analytical chemists to provide reliable analyses of most important environmental contaminants surpasses the ability of ecotoxicologists to interpret those concentrations.