3.40 - Sample Preparation for Food Contaminant Analysis

Abstract

Food samples cover a wide range of physical matrix types, including dry solid samples, biological matrices, such as meat and fats, and liquids or solutions. Food contamination can occur at any stage during production, processing, packaging, transportation, or storage. The term contaminants covers a diverse range of compounds including: residues of pesticides or veterinary drugs; contaminants found in the environment, such as dioxins and brominated flame retardants; compounds formed from molds, such as mycotoxins; compounds formed during heat treatment or processing, such as furan and acrylamide; or compounds transferred from packaging, such as phthalates, or the deliberate or accidental use of banned additives. The levels of such contaminants can vary greatly and for banned substances, such as some dyes or additives, the method of analysis must be capable of measuring as low as is reasonably practicable, to demonstrate their absence. Therefore sample preparation for the determination of contaminants in foods must be selective enough to separate the low levels of analyte from the complex matrix and also provide sufficient sensitivity (e.g., microextraction approaches to enable determination and unequivocal confirmation of compounds at trace and ultratrace levels). This chapter provides a general overview of the suitability of extraction methods for the determination of contaminants in foods at trace and ultratrace levels. The move toward microextraction methods that are more environmentally sustainable and have less environmental impact using less solvent and smaller sample sizes is explored.