Diazinon analysis

Chemical analysis. Tissues were homogenized before extraction. Diazinon and diazoxon was recovered from samples with n-hexane-acetone solvent extraction. 

Although the inhibition-based biosensors are sensitive, they are poor in selectivity and are rather slow and tedious since the analysis involves multiple steps of reaction such as measuring initial enzyme activity, incubation with inhibitor, measurement of residual activity, and regeneration and washing. Biosensors based on direct pesticide hydrolysis are more straightforward. The OPH hydrolyzes ester in a number of organophospho-rus pesticides (OPPs) and insecticides (e.g. paraoxon, parathion, coumaphos, diazinon) and chemical warfare agents (e.g. sarin) [53], For example, OP parathion hydrolyzes by the OPH to form p-nitrophenol, which can be measured by anodic oxidation. Rainina... 

Among all the compounds analyzed, only eight (OP, NP, TBP, BPA, diazinon, propanil, alachlor and molinate) appeared in both matrices. The most noticeable fact is that NP is the compound that contributes more than the other compounds in both water and sediments, as it has medium value for log K0w (4.48) and the concentrations found were high enough to enable its distribution between the two matrices, between 69 and 5,999 pg kg 1 in the solid matrix. These high concentrations in the sediments are in the same range as in other rivers of the world. This compound shows a lower importance in the PCA analysis because of its appearance as punctual pollutant, mainly around the industrial area of Zaragoza. The rest of the profile shows some differences between water and sediments. Water moves constantly while the sediments are more bound to one location, and in consequence, the... 

Eberle, D.O. 1974. Diazinon. I. Analysis of technical grade product, formulations, and residues. Residue Rev. 51 1-35. 

Fig.4 SPE-LC-DAD analysis of a wastewater sample. Peak identification number and peak retention times (min) (I) azinphosmethy, (11) parathion-methyl, (4) malathion, (3) feni-trothion, (8) azinphos-ethyl, (6) chlorphenvinphos, (10) parathion-ethyl, (7) diazinon [from ref. 21]...

In many applications nowadays it is essential to link a mass spectrometer to the gas chromatography in order to achieve positive identification and sensitivity of analysis. Some 12 types of compounds are listed in Table 1.11(a) which are based on the application of this technique, viz. polyaromatic hydrocarbons, polychlorobenphenyls, dioxins, chloro, carbamate and triazine types of herbicides and pesticides, Diazinon, Dicamba, Imidazoline and Cyperquat herbicides and herbicide pesticide mixtures. 

Lopez-Avila et al. [36] used a stable isotope dilution gas chromatography-mass spectrometric technique to determine down to O.lppb of pentachlorophenol (also Atrazine, Diazinon and lindane) in soil. Soil samples are extracted with acetone and hexane. Analysis is performed by high-resolution gas chromatography-mass spectrometry with mass spectrometer operated in the selected ion monitoring mode. Accuracy greater than 86% and a precision better than 8% were demonstrated by use of spiked samples. 

Specific tests are available to determine the presence of diazinon or its breakdown products in blood, body tissue, and urine. These tests are not routinely available through your doctor s office and require special equipment and sample handling. If you need the specific test, your doctor can collect the sample and send it to a special laboratory for analysis. This test is only useful if done within a few hours or days of exposure. This is because diazinon is rapidly broken down and excreted from the body. For more information on how to determine if you have been exposed to diazinon, see Chapters 2 and 6. 

Hematological Effects. Diazinon exposure is not likely to produce adverse effects on the blood and bone marrow in humans. Hematological analysis performed on samples from 5 individuals (3 males, 2 females) who intentionally ingested 60-180 mL of 25% diazinon solution (estimated to deliver a dose of... 

Although analysis of urine samples for the presence of these metabolites represents a potential means of assessing recent human exposure to diazinon, these metabolites can originate from exposure to other organophosphorus compounds and, therefore, are not specific for diazinon exposure. Additionally, these studies do not report a quantitative association between metabolite levels and exposure to diazinon in humans. Thus, these biomarkers are only indicative of exposure to diazinon (or other organophosphorus compounds) and are not specifically useful for diazinon exposure nor for dosimetric analysis. Further studies designed to refine the identification of metabolites specific to diazinon and provide dosimetric data will be useful in the search for a more dependable biomarker of diazinon exposure. 

The purpose of this chapter is to describe the analytical methods that are available for detecting, and/or measuring, and/or monitoring diazinon, its metabolites, and other biomarkers of exposure and effect to diazinon. The intent is not to provide an exhaustive list of analytical methods. Rather, the intention is to identify well-established methods that are used as the standard methods of analysis. Many of the analytical methods used for environmental samples are the methods approved by federal agencies and organizations such as EPA and the National Institute for Occupational Safety and Health (NIOSH). Other methods presented in this chapter are those that are approved by groups such as the Association of Official Analytical Chemists (AOAC) and the American Public Health Association (APHA). Additionally, analytical methods are included that modify previously used methods to obtain lower detection limits, and/or to improve accuracy and precision. 

Diazinon has a finite vapor pressure (see Chapter 3) and thus will be present in the air. A method for diazinon in air has been reported that is based on the use of polyurethane foam (PUF) to adsorb the pesticide from the air as the air is pulled through the PUF (Hsu et al. 1988). The PUF is then Soxhlet-extracted and the extract volume reduced prior to capillary GC/MS analysis. An LOD of 55 ng/m3 (5.5 m3 sample) and recovery of 73% were reported. Another study was described in which the diazinon levels in indoor air were monitored following periodic application of the pesticide for insect control (Williams et al. 1987). In this method, air is pulled through a commercially available adsorbent tube to concentrate diazinon. The tube is then extracted with acetone prior to GC/NPD analysis. No data were provided for the LOD, but recoveries in excess of 90% were reported at the 0.1 and 1 pg/m3 levels. This paper also indicated that diazinon can be converted to diazoxon by ozone and NOx in the air during the sampling process. 

The determination of diazinon in foods is important because this chemical is used as a pesticide on plant crops and, at least in some cases, in pesticide dips for the control of parasitic infestations in animals (Brown et al. 1987 Miyahara et al. 1992). Because animals are exposed to this compound, both via pesticide dips and by ingestion of crops to which diazinon has been applied, some methods have been reported for animal products. The majority of methods, however, deal with the determination of residues in plant products. Most of the analytical methods found that describe the extraction from, and determination of, diazinon residues in various crops (plant materials) were developed as part of multiresidue methods. They are based on homogenization of the sample with an organic solvent (polar or non-polar) the isolation of the residues from this initial extract and, usually, some additional cleanup prior to the analysis of the extract by GC. The most common non-MS modes of detection exploit the... 

Methods found for the determination of diazinon in animal products also used homogenization with a polar organic solvent as the first step in residue recovery. Toyoda et al. (1990) isolated diazinon from milk via partition into methylene chloride after extraction of the milk with 70% acetonitrile in water. Based on GC/FPD, an LOD of 10 ppb and a recovery of 89% (3.8% relative standard deviation) at 100 ppb were reported. Diazinon residues in eggs were studied (Leoni et al. 1992) after blending the eggs with acetone and partitioning into dichloromethane and acetone followed by C18-silica SPE. Based on GC/FPD analysis, an LOD of 1 ppb and a recovery of 93% at 13 ppb were reported. 

There are also methods for the analysis of diazinon degradation products in air, water, and soil. Williams et al. (1987) published a method for diazinon and its oxon (diazoxon) in air. Other methods have been reported for diazinon, its oxon, and hydrolysis products in water (Suffet et al. 1967), soils and water (Lichenstein et al. 1968), and soil (Burkhard and Guth 1979). The hydrolysis product 2-isopropyl-6-methyl-4-hydroxypyrimidine was studied along with diazoxon in submerged soil (Sethunathan and Yoshida 1969). Suffet et al. (1967) demonstrated the ability of GC to separate diazinon, diazoxon, and 2-isopropyl-6-methyl-4-hydroxypyrimidine. However, no validated methods for the determination of... 

Lawrence JF, Iverson F. 1975. Analysis of the diazinon metabolites G 27550 and GS 31144 by gas liquid chromatography with nitrogen-specific detection after derivatization. J Chromatogr 103 341-347. 

E. Escufn, S. Morais, R. T. Puchades, and A. Maquieira, Assessment of Novel Diazinon Immunoasays for Water Analysis, Environ. Sci. TechnoL 2004,38,... 

Methods of Analysis for Diazinon Residues, Geigy Co. Inc., New York. 

Three standard solutions were prepared—one containing 1 mg. of DDT and 1 mg. of DDD per 10 ml. of solvent the second containing 1 mg. of diazinon per 10 ml. of solvent and the other containing 1 mg. of ethion per 10 ml. of solvent (benzene). The retention time (time required after injection of the sample for the component to reach its maximum peak height) was used as a qualitative measure to identify the component. Quantitative information was obtained from the direct relationship of the concentration of insecticide to the maximum peak height. Standards were analyzed periodically during the analysis of the residues. 

Quantitative analysis of the organophosphorous pesticides acephate, azinphos, chlorpyrifos, coumaphos, diazinon, isazofos, malathion, methamidophos, parathion, pirimiphos, and their O.O-dimethyl analogues in human urine using LC-MS-MS [143]. 

A recent review has highlighted the stability of chemical species (in speciation studies) with respect to environmental matrices [1], These results are summarized in Table 4.2. It should be noted that samples must be analysed as quickly as possible after collection. The times given in this table are the maximum times that samples should be stored before analysis. It should also be noted that the guidelines given are general in nature. For example, many organophosphorus pesticides (not shown in Table 4.2) can be preserved by the addition of hydrochloric acid. However, as an exception to this, the (organophosphorus) pesticide diazinon breaks down when acidified. 

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