Multidimensional Chromatography in Pesticides Analysis

Abstract

The agricultural production of food and feed on an economically competitive basis needs an ever-increasing application of pesticides. Pesticide is a general term that includes variety of chemical and biological products to kill or control pests such as fungi, insects, rodents and weeds. In the European Union (EU) approximately 320,000 tonnes of active substances are sold every year, which accounts for one quarter of the world market (The Pesticides Safety Directorate, York, United Kingdom). Residues in fruit and vegetables, cereals, processed baby food and foodstuffs of animal origin are controlled through a system of statutory maximum residue limits (MRLs). The maximum residue limits (MRLs) are defined as: ‘The maximum concentration of pesticide residue (expressed as milligrams of residue per kilogram of commodity (mg/kg)) likely to occur in or on food commodities and animal feeds after the use of pesticides according to good agricultural practice (GAP)’ (Proposed PAHO/WHO Plan of Action for Technical Cooperation in Food Safety, 2006–2007). MRLs vary ordinarily within the interval 0.0008–50 mg/kg (The Applicant Guide: Maximum Residue Levels, The Pesticides Safety Directorate, York, United Kingdom), typically between 0.01 and 10 mg/kg for adult population. The lower values of MRLs are set for baby food—EC specified the MRL of 0.010 mg/kg (Pesticides and the Environment, A Strategy for the Sustainable Use of Plant Protection Products and Strategy Action Plans, London, United Kingdom), the lowest levels are set for particular special residues (Status of active substances under EU review (doc. 3010); Commission Directive 2003/13 and 14/; Council Directive 98/83/). The most efficient approach to pesticide analysis involves the use of chromatographic methods. Sometimes, the resolving power attainable with a single chromatographic system is still insufficient for the analysis of complex mixtures. The coupling of chromatographic techniques is clearly attractive for the analysis of multicomponent mixtures of pesticides. Truly comprehensive two-dimensional (2D) hyphenation is generally achieved by frequent sampling from the first column into the second, which is a very rapid analysis. In this study are presented different modes of multidimensional chromatographic separation techniques including multidimensional gas chromatography (MDGC), multidimensional liquid chromatography (MDLC) and multidimensional planar chromatography (MDPC) applied to analysis of pesticides.