实验基础

Occupational exposure to pesticides may occur not only during the actual application to crops and enclosed spaces, but also after the actual application when the crops are handled (e.g., harvesting) or when treated spaces are reentered. This postapplication (reentry) exposure may occur ...

An analytical method for the determination of commonly used insecticides and acaricides (pyrethroids, organophosphates, carbamates, organochlorine pesticides) in indoor air is described. Air samples are collected with a sampling train consisting of a glass fiber filter (GFF) a ...

Techniques to estimate bystander exposure are described. Passive sample media such as filter paper are used to collect spray drift. Air-sampling devices are used to determine the airborne concentration of pesticides. The use of a mannequin or volunteer dressed in a disposable coverall st ...

There is an increasing concern in pesticide residue analysis laboratories to ensure the quality of their analytical results. Internal quality control (IQC) measures are an essential element to ensure reliable results because they allow both the continuous monitoring of the process a ...

This chapter describes the use of enzyme-linked immunosorbent assay (ELISA) methods for the analysis of two potential environmental contaminants in food sample media: atrazine and 3,5,6-trichloro-2-pyridinol (3,5,6-TCP). Two different immunoassay formats are employed: a magn ...

This chapter describes a simple, fast, and inexpensive method for the determination of pesticides in foods and potentially other matrices. The method, known as the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for pesticide residues involves the extraction of the sample ...

The method presented is applicable to the determination of organophosphorus (OP) pesticide residues in vegetable oils. The method performs in a single step an on-column extraction and cleanup of OP pesticide residues by means of a system of three cartridges. A solution of 1 g oil in n-hexane is load ...

A method for determining pesticide residues in vegetables by low-pressure gas chromatography- tandem mass spectrometry (LPGC-MS/MS) is proposed after a fast and simple extraction of the vegetable with dichloromethane and without cleanup steps. The technique reduces the total time ...

We describe here a method using matrix solid-phase dispersion (MSPD) for the analysis of atrazine, metribuzin, cyanazine, and simazine in fish muscle tissue with a minimal amount of time and solvent consumed. A tissue sample is placed in a glass mortar containing a bonded-phase solid support ma ...

A method based on solid-phase extraction (SPE) and capillary electrophoresis-mass spectrometry (CE-MS) for determining fungicides in fruits and vegetables is described. The sample, previously chopped and homogenized, is extracted with a methanol-water mixture by sonication, ...

A supercritical fluid extraction (SFE) method using carbon dioxide (CO2) and cleanup by solid-phase extraction (SPE) with graphitized carbon black is presented. Gas chromatography using flame photometric detection (GC/FPD) and gas chromatography-mass spectrometric detec ...

Microwave-assisted extraction (MAE) is a simple, fast, and accurate method developed for the analysis of N,N-dimethyldithiocarbamate (DMDTC) and ethylenebis(dithiobamate) (EBDTC) fungicides in fruits and vegetables. Residues are extracted from the plant matrices and hydr ...

A method for the determination of individual α-hexachlorocyclohexane (α-HCH) enantiomers is described. The method consists of ultrasonic extraction, sulfuric acid-modified silica gel cleanup, fractionation on a polar silica solid-phase extraction (SPE) column, and final de ...

The method for the determination of multiclass pesticides in water samples by headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC-MS) is described. Of the 174 pesticides, 158 are extracted with a polyacrylate-coated fiber at 30 to 100�C and a ...

We have developed a method using in-tube solid-phase microextraction coupled with liquid chromatography-mass spectrometry (SPME-LC-MS) for the assay of herbicides in water samples. Chlorinated phenoxy acid herbicides have been automatically extracted into a DB-WAX capilla ...

Ion pair admicelle-based solid-phase extraction (SPE) is proved here to be a valuable strategy to concentrate quaternary ammonium compounds (quats; chlormequat, mepiquat, paraquat, diquat, and difenzoquat) from drinking water. The approach is based on the adsolubilization of qua ...

This chapter demonstrates the versatility and feasibility of coupled-column reversedphase liquid chromatography (LC/LC) for the rapid, selective, and sensitive determination of pesticides in environmental water samples. The work includes the setup and application of three ...

Solid-phase extraction (SPE) represents a suitable way to clean up and preconcentrate samples containing traces of chlorinated phenoxyacids. High selectivity levels may be obtained using columns packed with materials based on well-defined molecular recognition mechanism ...

An automated system appropriate for the analysis of a variety of chemical classes of pesticides and conversion products in water is presented. The system is based on the online solid-phase extraction (SPE) of target solutes followed by high-performance liquid chromatography (HPLC) ta ...

2-Alkyl-4-quinolones (AQs) such as 2-heptyl-3-hydroxy-4-quinolone (PQS) and 2-heptyl-4-quinolone (HHQ) are quorum sensing signal molecules. Here we describe two methods for AQ detection and quantification that employ thin layer chromatography (TLC) and microtitre plate assa ...