The role of liquid phase microextraction in plant and animal food analysis

Abstract

Food samples require extensive sample preparations for instrumental analyses due to the complex matrices involved. Food safety regulatory agencies also require sample preparation procedures that are accurate, sensitive, robust, and, above all, fast, to handle the requirements for determining the safety of the massive amounts of foods and food products needed for human, pet and livestock consumption. There is also an inseparable interconnection between environmental, agricultural, forensic, cosmetic and industrial analytical chemistry involved in this requirement, and advances in analytical methodology are simultaneously applicable to all of these realms. As a response to these needs, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was developed to provide multiclass analysis of agricultural products, and remains the basis for regulatory procedures for large scale analyses of food samples containing a wide variety of possible contaminants. However, since QuEChERS does not enhance analyte concentrations during sample preparation of these complex samples, the methodology also requires very expensive, very sensitive final analytical instrumentation, requiring highly trained personnel and continual maintenance. Smaller regulatory and field laboratories may also need sample preparation procedures for only a limited number of specific pesticides, metals, polycyclic aromatic hydrocarbons (PAHs) or other contaminants, requiring much less expensive and labor-intensive preparations and instrumentation. This is the role of liquid phase microextraction (LPME) in food sample preparation and analysis. LPME, individually or in combination with other sample preparation procedures, such as QuEChERS or traditional techniques such as solid phase extraction (SPE), can meet the requirements for sensitive and accurate analyses of specific analytes found in complex matrices, providing not only cleanup, but concentration of sample extracts, allowing the use of greener, less expensive and low maintenance final determination analytical instrumentation. Crucial review and application publications are tabulated to allow analysts easier access to appropriate publications to use this information for developing new or improved and greener validated methods for plant and animal food analyses.