Monitoring of pesticides

C. Aguilar, I. Feirer, R Bonnll, R. M. Marce and D. Barcelo, Monitoring of pesticides in river water based on samples previously stored in polymeric cartridges followed by on-line solid-phase extraction-liquid cliromatography-diode array detection and confirmation by atmospheric pressure chemical ionization mass spectrometry . Anal. Chim. Acta 386 237-248 (1999). 

S. Lacorte, J. J. Vreuls, J. S. Salau, R Ventura and D. Barcelo, Monitoring of pesticides in river water using fully automated on-line solid-phase extraction and liquid cliro-matography with diode array detection with a novel filrtation device , J. Chromatogr. 795 71-82(1998). 

Yess N, Gunderson E, Roy R. 1993. U.S. Food and Drug Administration monitoring of pesticide residues in infant foods and adult foods eaten by infants/children. J Assoc Off Anal Chem 76(3) 492-507. 

In this article, an analytical method is defined as series of procedures from receipt of a sample to final determination of the residue. Validation is the process of verifying that a method is fit for purpose. Typically, validation follows completion of the development of a method. Validated analytical data are essential for monitoring of pesticide residues and control of legal residue limits. Analysts must provide information to demonstrate that a method intended for these purposes is capable of providing adequate specificity, accuracy and precision, at relevant analyte concentrations and in all matrices analyzed. 

In the UK, most official monitoring of pesticide residues is concentrated in the Central Science Laboratory (CSL) of the Ministry of Agriculture, Fisheries and Food. Additionally, this laboratory is responsible for the data which have to be collected in... 

A 100-mL volume of benzene is added to the 20 g of air-dried soil and the mixture is shaken vigorously for 2h. After extraction twice with 100 mL of benzene, the combined extract is filtered through filter paper and the filter cake is washed with an additional 20 mL of benzene. The benzene extracts are dried over anhydrous Na2S04 and concentrated to dryness using a vacuum rotary evaporator. The residue is dissolved in an appropriate volume followed by GC/ECD analysis. For the monitoring of pesticide residues in soil, methanol for bifenox and oxyfluorfen and acetonitrile for nitrofen were recommended as the solvents for efficient extraction. ... 

European Commission, (2004). Monitoring of Pesticide Residues in Products of Plant Origin in the European Union, Norway, Iceland and Liechtenstein, 2001 Report, Sanco/17/04—Final/EC. 

Quintana J, Marti I, Ventura F (2001) Monitoring of pesticides in drinking and related waters in NE Spain with a multiresidue SPE-GC-MS method including an estimation of the uncertainty of the analytical results. J Chromatogr A 938 3-13... 

C. Aprea, C. Colosio, T. Mammone, C. Minoia and M. Maroni, Biological monitoring of pesticide exposure a review of analytical methods, J. Chromatogr. B. Anal. Tech. Biomed. Life Sci., 769 (2002) 191-219. 

J. Pritchard, L.A. Law, A. Vakurov, P. Millner and S.P.J. Higson, Sonochemically fabricated enzyme microelectrode arrays for the environmental monitoring of pesticides, Biosens. Bioelectron, 20 (2004) 765-772. 

Regarding the sampling in food residues, a representative sample consists of a large number of randomly collected units. Monitoring of pesticide residues for MRL compliance involves analysis of a composite sample, made up of a number of individual units [1]. The storage of a laboratory sample of homogenated or intact tissue may influence the final determined residue content dramatically. Samples should be analyzed without any delay, as some pesticide residues may degrade rapidly. 

The monitoring of pesticides other than cholinesterase inhibitors is done by measuring the concentrations of the compound or its metabolites in blood and urine. 

Conducted by the University of Minnesota, the FFES is a study of pesticide workers that includes limited biomonitoring. About 95 farm families in Minnesota and South Carolina are involved in regular monitoring of pesticide exposure (Farm Family Exposure Study 2005). After pesticide exposure at the farms, urine samples are collected for 24 hours/day for 4 days. A baseline 24-hour sample is collected before pesticide application. The study is expected to improve exposure assessment in epidemiologic studies of agricultural populations (Baker et al. 2005). 

Monitoring of pesticide residues in the US also occurs at the state level. California is the largest state in the US in terms of both agricultural production and population and also possesses, by far, the most comprehensive state regulatory program for pesticides. In 1997, California s Marketplace Surveillance Program analyzed 5660 samples (62.2 percent from California, 6.7 percent from other states, 31.1 percent from other countries) for pesticide residues. The results from this program are shown in Fig. 14.3 and demonstrate that the majority of samples (62.1 percent) contained no detectable residues... 

Studies on water pollution by POPs can be categorized according to the water bodies studied, such as rivers, seas, and oceans harbors, lakes, and reservoirs and groundwater. They can also be categorized according to sample types, e.g., surface water, deepwater, surface micro-layer, and pore water in sediments. In China, extensive monitoring of pesticide POPs has been carried out in rivers, bays and harbors, and lakes. The results show that the spatial differences of pesticide concentrations in water are larger than that in air, but smaller than that in soil. 

Fernandez-Alba, A.R., A. Aguera, M. Contreras, et al. 1998. Comparison of various sample handling and analytical procedures for the monitoring of pesticides and metabolites in ground waters. J. Chromatogr. A 823 35-47. 

Lee, N.A. and I.R. Kennedy. 2001. Environmental monitoring of pesticides by immunoanalytical techniques Validation, current status, and future perspectives. J. AOAC Int. 84 1393-1406. 

Both the automatic coulometric titration of petroleum streams and the continuous monitoring of pesticides and sulfur-halogen compounds indicate that the coulometric titrator method is amenable to the automatic maintenance of the concentration of a component in a solution system. A manual version of this approach has been used to study the kinetics of hydrogenation of olefins as well as to determine the rate of hydrolysis of esters.12 The latter system is a pH-stat that is based on the principles of coulometric titrations. Equations (4.9)-(4.11) indicate how this approach is applied to the evaluation of the rate constants for ester hydrolysis. A similar approach could be used to develop procedures for kinetic studies that involve most of the electrochemical intermediates summarized in Table 4.1. The coulometric titration method provides a convenient means to extend the range of systems that can be subjected to kinetic study in solution. 

Mansour, S.A., Belal, M.H., Abou-Arab, A.A.K., Gad, M.F. Monitoring of pesticides and heavy metals in cucumber fruits produced from different farming systems. Chemosphere 75, 601-609 (2009)... 

The FBI has been widely apphed for identification, confirmation of identity as well as quantitative analysis in a variety of apphcation areas, especially in the analysis of pesticides. The interest of the US Envirornnental Protection Agency (US-EPA) in the use of the PBI for envirornnental monitoring of pesticides obviously contributed significantly to the proliferation of the system. 

In spite of the worldwide controversy which has surrounded the use of pesticides for many years, there can be little doubt that they provide one of the most effective contributions to increasing crop production and they have helped the farmer to improve the quality and variety of our foodstuffs. However, even when used correctly, these compounds can cause ecological consequences, public health problems, and the occurrence of toxic residues in foodstuffs. These problems make necessary the development of analytical methodologies that allow the appropriate monitoring of pesticides residues. 

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