Multiclass pesticides

Since the analytical point of view most of current analytical methods are based on LC-MS/MS, but for some classes of pesticides GC-MS continues being the technique of choice. The use of quadrupole ion trap (QIT) to analyze multiple pesticide residues is limited to several multiclass pesticides in fruit [162], because of the limited number of ions that can be isolated at the same time. For this reason, the use of several time windows is required and this is indeed a strong limitation in practice. The use of hybrid triple quadrupole linear ion trap (QqLlT) mass spectrometer has provided significant contribution to the development of high-sensitive multiresidue analytical methods for pesticide control. An example of application is the method reported by Hernando et al. for the analysis of pesticide residues in olive oil [65]. 

Gonzalez-Rodriguez, J., Garrido-Frenich, A., Arrebola, F. J., and Martinez-Vidal, J. L., Evaluation of low pressure gas chromatography linked to ion-trap tandem mass spectrometry for the fast trace analysis of multiclass pesticide residues. Rapid Commun. Mass Spectrom., 16, 1216-1224, 2002. 

Elution patterns of multiclass pesticides from three types of anion exchange cartridges (K. lijima, Inst, of Environ. Tox., Japan)... 

Pesticides encompass a large assortment of organic compounds, several of which are positional, geometrical, and optical isomers, with differing degrees of ionization, polarity, and water solubility. Many exhibit spectrochemical, electrochemical, or other functional properties suitable for detection. Unless the pesticide class is explicitly charged, single- and multiclass pesticide analyses are usually assessed by EKC modes. Several excellent review articles have covered the literature on pesticide analysis by CE in the past 5 years. ... 

Amvrazi, E. Tsiropoulos, N. (2009). Chemometric Study and Optimization of Extraction Parameters in Single-Drop Microextraction for the Determination of Multiclass Pesticide Residues in Grapes and Apples by Gas Chromatography Mass Spectrometry. /, Chromatogr. A, Vol.1216, N°14, pp. 7630-7638, ISSN 00219673. 

Economou, A., Botitsi, H., Antoniou, S., and Tsipi, D. 2009. Determination of multiclass pesticides in wines by solid-phase extraction and liquid chromatography-tandem mass spectrometry. J. Chromatogr. A 1216 5856-5867. 

Anagnostopoulos, C. and MUiadis, G. E. 2013. Development and vahdation of an easy multiresidue method for the determination of multiclass pesticide residues using GC-MS/MS and LC-MS/MS in ohve oil and olives. Talanta 112 1-10. 

Cherta E, Portoles T, Beltran J, Pitarch E, Mol JG, Hernandez F. Application of gas chroma-tography-(triple quadrupole) mass spectrometry with atmospheric pressure chemical ionization for the determination of multiclass pesticides in fruits and vegetables. J Chromatogr A. 

There are a large number of literature references that refer the use of SPE cartridges for the extraction of pesticides from water. There are several comprehensive reviews of the use of SPE, including that by Soriano et al. who discussed the advantages and limitations of a number of sorbents for the analysis of carbamates. Hennion reviewed the properties and uses of carbon based materials for extraction of a wide multiclass range of pesticides. Thorstensen et al. described the use of a high-capacity cross-linked polystyrene-based polymer for the SPE of phenoxy acids and bentazone, and Tanabe et al reported the use of a styrene-divinylbenzene copolymer for the determination of 90 pesticides and related compounds in river water. SPE cartridges are also widely used for the cleanup of solvent extracts, as described below. 

For detection, MS is rapidly becoming the method of choice for multiclass, multiresidue analysis owing to its many advantages, recent improvements in technology, and availability of cost-effective commercial instrumentation. Detection systems in general are continually being improved, and in combination with the improvements in chromatographic instruments and techniques, an exceptionally low limit of detection (LOD) is possible for pesticide residues. 

Sancho J.V., Pozo O.J., and Hernandez F., 2004. Liquid chromatography and tandem mass spectrometry A powerful approach for the sensitive and rapid multiclass determination of pesticides and transformation products in water. Analyst 129 38. 

OP compounds and carbamate are widely used as insecticides, pesticides, and warfare agents [20,21], Detection of pesticides is usually carried out by multiresidue methods (MRMs) of analysis, which are able to detect simultaneously more than one residue and have been developed mainly based on chromatographic techniques. Two groups of MRMs are used (i) multiclass MRMs that involve coverage of residues of various classes of pesticides, and (ii) selective MRMs, which concern multiple residues of chemically related pesticides (e.g., IV-methyl carbamate pesticides (NMCs), carboxylic acids, phenols, etc.). As foods are usually complex matrices all of the pre-analytical steps (matrix modification, extraction, and clean-up) are often necessary. 

Sherma, J. Shafik, T.M. A multiclass, multiresidue analytical method for determining pesticide residues in air. Arch. Environ. Contamin. Toxicol., 1975, 3, 55. 

Liquid chromatography-mass spectrometry The initial attempts to couple LC with MS lacked important attributes for trace analysis sensitivity, robustness, and reliable quantitation. Moreover, the cost of the early LC-MS instruments was prohibitive for most laboratories. The revolutionary introduction of atmospheric pressure ionization (API) techniques, mainly electrospray (ESI) and atmospheric pressure chemical ionization (APCI), resulted in greater applicability of LC-MS and manufacture of more reliable, affordable, and user-friendly instruments. Thus, LC-MS is now becoming an indispensable part of the analytical strategy in many routine laboratories, enabling direct, selective, and sensitive multiclass, multiresidue analysis of more polar, low volatile, and/or thermolabile pesticides, such as carbamates, phenylureas, sulfonylureas, imidazoles, triazoles, imidazolinones, chlorophenoxy acids, and many others. 

Lehotay SJ (2000) Multiclass, multiresidue analysis of pesticides, strategies for. In Meyers RA (ed.) Encyclopedia of Analytical Chemistryp, pp. 6344-6384. Chichester Wiley. 

On the other hand, the QuEChERS (quick, easy, cheap, effective, rugged, and safe) method, originally developed for pesticide analysis [23], has been also applied to the determination of multiclass veterinary drugs in different food commodities [24—27], The conventional QuEChERS strategy applies acetonitrile extraction, followed by removal of water and proteins by salting out with sodium chloride and magnesium sulphate. Afterwards, dispersive SPE (d—SPE) is usually applied. The QuEChERS approach has many advantages, as it is simple and quick, reduces the... 

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