Pesticides analysis for

Roach JA, Andrzejewski D. 1987. Analysis for pesticide residues by collision-induced fragmentation. In Rosen JD, ed. Applications of new mass spectrometry techniques in pesticide chemistry. New York, NY Wiley Co., 187-210. 

Residues monographs, which contain information on pesticide use patterns, data on the chemistry and composition of pesticides, methods of analysis for pesticide residues, and information on MRLs, are published in the FAO Plant Production and Protection Paper series. 

Qualitative analysis for pesticides and PAHs - ecotoxicity tests... 

Figure 75. Multiple-wavelength scan in the analysis for pesticides in drinking water...

Since 1980, WHO activities concerned with the safety assessment of food chemicals have been incorporated into 1F CS. Members invited by WHO review toxicological and related data and e.stimatc, when possible, ADIs of the pesticides for humans. Members invited by FAO review pesticide use paiiems (GAPs), data on chemistry composition of pesticides and methods of analysis for pesticide residues, and estimate MRLs that may occur as a result of the use of the pesticides according to GAPs, These MRLs serve as the basis for international standards established by the Codex Alimentarius Commission, which is administered... 

Although GC/MS techniques remain the basic hallmark of analysis for pesticides and their derivatives, it is important to stress the need and the specific role of additional methodologies such as thermal energy analysis and electrochemical detectors. The former technique was discussed with particular emphasis on its utility of the determination of trace levels of nitrosamines and nitrosated pesticides in agricultural products and residues. 

Traditional methods (1-3) of analysis for pesticide residues in foods use a four-step approach ... 

Figure 5.37 Examples of LC-MS/MS multiresidue analysis for pesticides spiked into lemon at 0.1 mg.kg , using the ECHO technique. The first (black) peaks are the echo peaks corresponding to injection of calibration standards in solvent at 0.1 p,g.mL , and the second peaks correspond to the injection of the extract of spiked lemon. Reproduced from Alder, J. Chromatogr. A 1058, 67 (2004), copyright (2004), with permission from Elsevier.

Hartmann, H. et al.. Rapid target analysis for pesticides in water by online coated capillary microextraction combined with liquid chromatography and tandem mass spectrometry, ]. AOAC Int., 83, 762, 2000. 

Two examples from the analysis of water samples illustrate how a separation and preconcentration can be accomplished simultaneously. In the gas chromatographic analysis for organophosphorous pesticides in environmental waters, the analytes in a 1000-mL sample may be separated from their aqueous matrix by a solid-phase extraction using 15 mb of ethyl acetate. After the extraction, the analytes are present in the ethyl acetate at a concentration that is 67 times greater than that in... 

A chromatographic analysis for the chlorinated pesticide Dieldrin gives a peak with a retention time of 8.68 min and a baseline width of 0.29 min. How many theoretical plates are involved in this separation Given that the column used in this analysis is 2.0 meters long, what is the height of a theoretical plate ... 

Pesticides. Chlorinated hydrocarbon pesticides (qv) are often found in feed or water consumed by cows (19,20) subsequently, they may appear in the milk, where they are not permitted. Tests for pesticides are seldom carried out in the dairy plant, but are most often done in regulatory or private specialized laboratories. Examining milk for insecticide residues involves extraction of fat, because the insecticide is contained in the fat, partitioning with acetonitrile, cleanup (FlorisH [26686-77-1] column) and concentration, saponification if necessary, and determination by means of paper, thin-layer, microcoulometric gas, or electron capture gas chromatography (see Trace and residue analysis). 

T. Cairns and J. Sherma, eds.. Comprehensive Analytical Profiles of Important Pesticides, CRC Press, Boca Raton, Fla., 1992, 304 pp. From the series ModemMethods for Pesticide Analysis, provides detailed information on properties and analytical methodology for nine prominent pesticides, pyrethroids, and fumigants in food. Includes formulations and uses, chemical and physical properties, toxicity data, and tolerances on various foods and feeds. Analytical information may be given in enough detail for methods to be carried out without having to consult additional Hterature sources. 

ON-LINE COUPLING OF SPE-HPLC-MS/MS FOR FAST TRACE ANALYSIS OF PESTICIDES IN DRINKING AND SURFACE... 

A method which uses supercritical fluid/solid phase extraction/supercritical fluid chromatography (SE/SPE/SEC) has been developed for the analysis of trace constituents in complex matrices (67). By using this technique, extraction and clean-up are accomplished in one step using unmodified SC CO2. This step is monitored by a photodiode-array detector which allows fractionation. Eigure 10.14 shows a schematic representation of the SE/SPE/SEC set-up. This system allowed selective retention of the sample matrices while eluting and depositing the analytes of interest in the cryogenic trap. Application to the analysis of pesticides from lipid sample matrices have been reported. In this case, the lipids were completely separated from the pesticides. 

Figure 10.14 Schematic representation of the SFSPE/SFC set-up developed by Murugaverl and Vooi hees (67). Reprinted from Journal of Microcolumn Separation, 3, B. Mumgaverl and K. J. Vooi hees, On-line supercritical fluid exti aaion/chromatography system for ti ace analysis of pesticides in soybean oil and rendered fats , pp. 11-16, 1991, with permission from John Wiley and Sons, Inc.

LC-GC, therefore, shows promise for forensic science applications, reducing sample handling and preparation steps by essentially using an on-line LC column in place of one or more extraction steps. This is followed by a traditional high resolution GC analysis. The methods described here for pesticides and hormones could be readily adapted to a variety of analyses, especially those involving fatty matrices. Such as tissues, food or blood. 

Comprehensive two-dimensional GC has also been employed for the analysis of pesticides from serum, which, although not strictly a forensic analytical problem , provides an example of the promise of this technique to forensic applications, such as the analysis of drugs of abuse (40). Two-dimensional gas chromatograms of a 17-pesticide standard and an extract from human serum are shown in Figure 15.13. The total analysis time of about 5 min, high peak capacity and the separation of all... 

For pesticide extraction procedures pertaining to food samples, refer to U.S. government manuals on pesticide residue analysis. 

Groundwater has also been surveyed for methyl parathion. In a study of well water in selected California communities, methyl parathion was not detected (detection limit of 5 ppb) in the 54 wells sampled (Maddy et al. 1982), even though the insecticide had been used in the areas studied for over 15 years. An analysis of 358 wells in Wisconsin produced the same negative results (Krill and Sonzogni 1986). In a sampling of California well water for pesticide residues, no methyl parathion was detected in any of the well water samples (California EPA 1995). In a study to determine the residue levels of pesticides in shallow groundwater of the United States, water samples from 1,012 wells and 22 springs were analyzed. Methyl parathion was not detected in any of the water samples (Kolpin et al. 1998). In a study of water from near-surface aquifers in the Midwest, methyl parathion was not detected in any of the water samples from 94 wells that were analyzed for pesticide levels (Kolpin et al. 1995). 

EPA. 1980d. Analysis of pesticide residues in human and environmental samples A compilation of methods selected for use in pesticide monitoring programs. Research Triangle Park, NC U.S. Environmental Protection Agency, Health Effects Research Laboratory. EPA-600/8-80-038. NTIS PB82-208752. 

Bennett DA, Chung AC, Lee SM. 1997. Multiresidue method for analysis of pesticides in liquid whole milk. JAOACInt 80(5) 1065-1077. 

Fukuhara K, Takeda M, Uchiyama M. 1977. [Studies on analysis of pesticide residues in foods (XXV) Analytical method for endosulfan in crops.] ShokuhinEiseigakuZasshi 18 149-153. (Japanese)... 

Zweig G, Sherma J. 1972. Thiodan (endosulfan). In Zweig G, Sherma J, eds. Analytical methods for pesticides and plant growth regulators. Vol. VI. Gas chromatographic analysis. New York, NY Academic Press, 511-513. 

Analytical laboratories need an area where incoming samples can be sorted and recorded. The size of this is hard to overestimate. In addition, some laboratories need an area where samples can be prepared for analysis. A pesticide laboratory, for instance, may want to set aside a complete room for such work, since it is often quite messy. 

Many pesticides are neurotoxicants poisoning the nervous system. A number of pesticides are acetyl cholinesterase inhibitors (Serat and Mengle 1973). Generally, pesticides determination has been performed by GC since the 1960 s (Morrison and Durham 1971 Fournier et al. 1978). There are no reference materials for pesticides in urine or serum, although as with PAHs there are a number biological matrices certified for the content of various pesticides available for environmental food and agriculture analysis and which may have some application in clinical chemistry. 

Established in 1894, AOAC International is an independent association of scientists and organizations in the public and private sectors devoted to promoting methods validation and quality measurements in the analytical sciences. AOAC has a mission to ensure the development, testing, validation, and publication of reliable chemical and biological methods of analysis for foods, drugs, feed-stuffs, fertilizers, pesticides, water, forensic materials and other substances affecting public health and safety and the environment. 

Several articles and books have been published dealing with this subject. In this article, some of the techniques which are relevant to methods for the analysis of foods for pesticide residues will be discussed. 

In summary, the procedure of the Nordic Committee describes a comprehensive validation protocol, but it is not specially designed for pesticide residue analysis and has no preferences with regard to single- or inter-laboratory validation. Therefore, if it is applied to pesticide residue methods, some specific validation requirements should be added. The procedure clearly lists all necessary steps of validation and adjusts its recommendations to the degree of previous external validation. 

---