Pesticides In Biological Samples Research Articles

Detection reagents used for on-plate identification of organic pesticides in biological samples with preliminary separation by TLC/HPTLC

Many specific and non-specific chromogenic spray reagents have been used to detect organic pesticides (organophosphorus, organochlorine, carbamates, and pyrethroids) on thin-layer chromatographic (TLC)/high-performance thin-layer chromatographic (HPTLC) plates. To realize high sensitivity and improved selectivity, several chromogenic reagents have been introduced. The physical properties of organic pesticides reported so far are also presented in tabular form. The colors produced on TLC plates due to reactions taking place between pesticides and spray reagents are illustrated in the form of chromatograms, and reaction mechanism is also presented.

A simple solvothermal process for fabrication of a metal-organic framework with an iron oxide enclosure for the determination of organophosphorus pesticides in biological samples

An active magnetic metal-organic framework (MOF) hybrid material was prepared using a novel in situ solvothermal method in the presence of magnetite (Fe3O4) particles, that holds much promise for large-scale synthesis. MIL-101(Fe), an iron terephthalate with pore structure and high resistance to water and common solvents, was functionalized as a model with superparamagnetic qualities, using Fe3O4. The electrostatic interaction between Fe3O4 and metal ions was thereby used to chemically stabilize magnetic nanoparticles, and thus MOF crystals were uniformly enclosed by Fe3O4 to form a homogeneous magnetic product identified as a Fe3O4/MIL-101 composite. This hybrid material with magnetic susceptibility but with the lowest possible loading amount of Fe3O4 was examined, and its potential application for magnetic solid-phase extraction of six organophosphorus pesticides (OPPs) from human hair and urine samples, followed by gas chromatography analysis, was assessed. The main effect parameters including solution ionic strength, desorption solvent, extraction time and desorption time were investigated in sequence. Under optimized conditions, this method showed low detection limits (0.21–2.28ng/mL), wide linearity, and good precision (1.8–8.7% for intra-day, 2.9–9.4% for inter-day). The matrix interference produced by hair or urine could be effectively eliminated using this method, and satisfactory recoveries of the spiked samples were 76.8–94.5% and 74.9–92.1%, respectively, indicating that the Fe3O4/MIL-101 sorbents are feasible for the analysis of trace analytes from biological samples.

Determination of currently used pesticides in biota

Although pesticides enable control of the quantity and quality of farm products and food, and help to limit diseases in humans transmitted by insects and rodents, they are regarded as among the most dangerous environmental contaminants because of their tendency to bioaccumulate, and their mobility and long-term effects on living organisms. In the past decade, more analytical methods for accurate identification and quantitative determination of traces of pesticides in biota have been developed to improve our understanding of their risk to ecosystems and humans. Because sample preparation is often the rate-determining step in analysis of pesticides in biological samples, this review first discusses extraction and clean-up procedures, after a brief introduction to the classes, and the methods used in the analysis of pesticides in biota. The analytical methods, especially chromatographic techniques and immunoassay-based methods, are reviewed in detail, and their corresponding advantages, limitations, applications, and prospects are also discussed. This review mainly covers reports published since 2008 on methods for analysis of currently used pesticides in biota.

Solid phase microextraction gas chromatographic analysis of organophosphorus pesticides in biological samples

Headspace-solid phase microextraction (HS-SPME) was studied and optimised for the determination of four common organophosphorus pesticides (OPPs) in biological samples. Various parameters controlling SPME were studied: choice of SPME fiber, type and content of salt added, preheating and extraction time, desorption time, extraction temperature. Capillary gas chromatographic analysis with nitrogen phosphorus detection (GC–NPD) facilitates sensitive and selective detection of the OPPs: malathion, parathion, methyl parathion and diazinon. Fenitrothion was used as the internal standard. The method was applied to the determination of the pesticides in human biological specimens: whole blood, blood plasma, urine, cerebrospinal fluid, liver and kidney. Limits of detection ranged from 2 to 55 ng/ml depending on pesticide and type of specimen. The developed methodology overcomes limitations and obstacles of conventional methods such as the use of organic solvents, the formation of emulsions and the tedious-cumbersome procedures. The proposed protocol is seen as an attractive alternative to be used in routine toxicological analysis.

Separation methods for amino group-possessing pesticides in biological samples

The separation methods for pesticides include liquid–liquid extraction, solid-phase extraction and solid-phase microextraction, gas chromatography (GC), GC–mass spectrometry (MS), GC–MS–MS, high-performance liquid chromatography (LC), LC–MS and LC–MS–MS. This review deals with each technique commonly used for extraction, chromatographic separation and detection of amino group possessing pesticides, such as diazines, triazines, carbamates, dinitroanilines and chloroacetanilides in biological samples. The methods presented for analysis of the pesticides in complicated biological matrices seem to be easily applicable to surface or groundwater in environmental chemistry.

Rapid Analysis of Pesticides Causing Acute Poisoning in Patients by High-performance Liquid Chromatography with Column-switching Technique

Rapid identification and quantification of pesticides in biological samples in cases of poisoning are very important in improving the survival rate in such cases. We previously investigated the effectiveness of a screening and quantification method for fat-soluble pesticides by HPLC equipped with a photo-diode-array detector (HPLC-DAD). In the present study, we investigated a more rapid method of screening and quantitative analysis of 10 important fat-soluble pesticides (propanil(DCPA), fenobucarb(BPMC), pyridaphenthion, napropamide, isoprothiolane, malathion, fenitrothion (MEP), edifenfos(EDDP), diazinon, and isoxathion) employing column-switching HPLC-DAD together with a direct injection method of biological samples. The detection limits of the 10 pesticides were less than 10ng per injection, except for isoxathion in artificial gastric juice and urine. Linear calibration curves for the 10 fat-soluble pesticides in artificial gastric juice were in the range of 1-250μg/ml, and in serum and urine were in the range of 0.1-50μg/ml (except for isoxathion in urine). The recovery rates of all pesticides were greater than 80%, except for fenitrothion and diazinon in artificial gastric juice, edifenfos in serum, and diazinon and isoxathion in urine. This method was applied to three actual cases of acute poisoning, and we were able to provide important information to doctors on the basis of the rapid method of screening and quantitative analysis of pesticides in biological samples. The direct injection method in this paper could shorten analyzing time by 1-1.5h compared to the previous method that necessitating solvent extraction prior to HPLC analysis.