Multiresidue Method for Determination of Pesticides in Kiwif ruit, Apples, and Berryfruits

1983 ◽  
Vol 66 (4) ◽  
pp. 1003-1008
Author(s):  
P T Holland ◽  
T K Mcghie
Keyword(s):  
Gas Chromatography ◽  
Water Soluble ◽  
Electron Capture Detection ◽  
Synthetic Pyrethroids ◽  
Photometric Detection ◽  
Flame Ionization ◽  
Organochlorine Insecticides ◽  
Routine Surveillance ◽  
Wide Range

Abstract A rapid multiresidue procedure for fruits, based on methanol extraction, is presented. Water and highly water-soluble co-extractives are removed by partitioning the pesticides into toluene. Carbon-cellulose-Florisil cleanup is performed before gas chromatography on OV-225 with electron capture detection. A wide range of pesticides can be determined to 0.1 mg/kg without concentrating the extract. Gas chromatography of the crude toluene partition using SE-30 and an alkali flame ionization detector provides confirmatory data and allows detection of some carbamates. Dichlorvos, dimethoate, and acephate are determined directly in the methanol extract by flame photometric detection. High recoveries were obtained for 4 organochlorine insecticides, 13 organophosphorus insecticides, 2 synthetic pyrethroids, two JV-methyl carbamates, and 10 fungicides. The method is economical of solvents, glassware, and time, and is recommended for routine surveillance of residue levels on fruit.

Residue Analysis of Organophosphorus and Organochlorine Pesticides in Fatty Matrices by Gas Chromatography Coupled with Electron-Capture Detection

2006 ◽  
Vol 61 (5-6) ◽  
pp. 341-346 ◽  
Author(s):  
Jae-Woo Park ◽  
A. M. Abd El-Aty ◽  
Myoung-Heon Lee ◽  
Sung-Ok Song ◽  
Jae-Han Shim
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Simple Procedure ◽  
Linear Regression Analysis ◽  
Residue Analysis ◽  
Electron Capture Detection ◽  
Relative Standard ◽  
Wide Range ◽  
Repeatability And Reproducibility

A multiresidue method for the simultaneous determination of 22 organochlorine (OCs) and organophosphorus (Ops) pesticides (including isomers and metabolites), representing a wide range of physicochemical properties, was developed in fatty matrices extracted from meat. Pesticides were extracted from samples with acetonitrile/n-hexane (v :v, 1:1). The analytical screening was performed by gas chromatography coupled with electron-capture detection (ECD). The identification of compounds was based on their retention time and on comparison of the primary and secondary ions. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of samples fortified at 38 to 300 ng/g levels. Correlation coefficients for the 22 extracted pesticide standard curves (linear regression analysis, n = 3) ranged from 0.998 to 1.000. Recovery studies from 2 g samples fortified at 3 levels demonstrated that the GC-ECD method provides 64.4-96.0% recovery for all pesticides except 2,4′-DDE (44.6-50.4%), 4,4′-DDE (51.1-57.5%) and 2,4′-DDT (50.0-51.2%). Both repeatability and reproducibility relative standard deviation values were < 20% for all residues. Detection limits ranged from 0.31 to 1.27 ng/g and quantification limits were between 1.04 and 4.25 ng/g. The proposed analytical method may be used as a simple procedure in routine determinations of OCs and Ops in meat. It can also be applied to the determination of pesticide multi-residues in other animal products such as butter and milk.

Modification of AOAC Multiresidue Method for Determination of Synthetic Pyrethroid Residues in Fruits, Vegetables, and Grains. Part I: Acetonitrile Extraction System and Optimization of Florisil Cleanup and Gas Chromatography

1995 ◽  
Vol 78 (6) ◽  
pp. 1481-1488 ◽  
Author(s):  
Guo-Fang Pang ◽  
Yan-Zhong Chao ◽  
Chun-Lin Fan ◽  
Jin-Jie Zhang ◽  
Xue-Min Li ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Fruits And Vegetables ◽  
Electron Capture Detection ◽  
Synthetic Pyrethroids ◽  
Capillary Gc ◽  
Pyrethroid Insecticides ◽  
Multiresidue Method ◽  
Polished Rice ◽  
The Individual

Abstract We present a multiresidue method for determination of synthetic pyrethroids in fruits, vegetables, and grains. The method is a modification of AOAC Method 970.52. Residues are extracted with acetonitrile (for fruits and vegetables) or acetonitrile–water (2 + 1) (for grains) and then transferred to hexane. Coextractives are removed by acetonitrile partitioning and open-column chromatography with deactivated Florisil. The final extract is analyzed by gas chromatography with electron capture detection (GC–ECD). An HP-17 wide-bore column is used to determine the total isomeric content of each insecticide, and a DB-5 narrow-bore column is used to determine the individual isomeric contents of each insecticide. The method was used to recover 8 pyrethroids (biphenthrin, fenpropathrin, cyhalothrin, permethrin, cypermethrin, fluvalinate, fenvalerate, and deltamethrin) spiked at 0.01–4.0 mg/kg in 20 crops (apple, pear, peach, banana, grape, strawberry, potato, tomato, cucumber, pepper, cabbage, carrot, celery, polished rice, wheat, green gram, buckwheat, sorghum, maize, and barley). Recoveries of the 8 pyrethroid insecticides in 6 crops ranged from 83.8 to 112.8%, with a coefficient of variation (CV) of 2.00 to 12.09% for the narrow- bore capillary GC (n = 6) and from 82.8 to 106.4%, CV = 2.93–12.19%, for the wide-bore capillary GC (n = 6). The minimum detectable levels of 0.004–0.028 mg/kg (for fruits and vegetables) or 0.01–0.08 mg/kg (for grains) for the 8 pyrethroids are easy to detect.

Determination of Ethylenethiourea in Grapes and Wine

1985 ◽  
Vol 68 (4) ◽  
pp. 741-745
Author(s):  
Jana Chovancova ◽  
Eva Matisova ◽  
Vojtech Batora
Keyword(s):  
Gas Chromatography ◽  
Detection Limit ◽  
Electron Capture ◽  
Paper Chromatography ◽  
Capillary Gas Chromatography ◽  
Electron Capture Detection ◽  
Flame Ionization Detection ◽  
Flame Ionization ◽  
Concentration Levels

Abstract Residues of ethylenethiourea (ETU) in grapes and wine were deter- [ mined by capillary gas chromatography and paper chromatography, without a cleanup step, and after derivatization to 5-benzyl-ETU. The ! detection limit was 0.0002 mg/kg for flame ionization detection, 0.008 mg/kg for paper chromatography with photodensitometric evaluation of the detected spot. Results were compared with a generally used GC method specifying electron capture detection of trifluoroacetylated S- benzyl-ETU. The recoveries of ETU in grapes and wine at different j concentration levels were determined. ETU residues were determined J in treated grapes but no residues were detected in wine

scholarly journals Determination of Eight Synthetic Pyrethroids in Bovine Fat by Gas Chromatography with Electron Capture Detection

2006 ◽  
Vol 89 (5) ◽  
pp. 1425-1431 ◽  
Author(s):  
Christine J Akre ◽  
James D MacNeil
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Solid Phase ◽  
Plant Protection ◽  
Electron Capture Detection ◽  
Synthetic Pyrethroids ◽  
Routine Monitoring ◽  
Chromatographic Peaks ◽  
Time Required

Abstract Synthetic pyrethroids are among the most widely used classes of insecticides, and their uses are varied, including plant protection, animal dips, and as a treatment for human clothing and bedding in very hot climates. Veterinary applications include ear tags, pour-on formulations, sprays, and dips. Persistent residues have been reported in livestock, and routine monitoring programs in other countries have found detectable residues of various pyrethroids in fat. A method has been developed using solid-phase extraction that reduces the quantities of solvents used, the time required, and the amount of glassware used compared to an earlier method on which it was based. The scope of analytes tested included the 5 compounds cited in the earlier method (flucythrinate, permethrin, cypermethrin, fenvalerate, and deltamethrin) and, in addition, cyfluthrin, λ-cyhalothrin, and fluvalinate. Sample extracts were analyzed by gas chromatography with electron capture detection using selected chromatographic peaks characteristic of each compound. Limits of quantification for the compounds were from 25-50 μg/kg, with a linear response for all compounds to 200 μg/kg. Recoveries ranged from 80 to 123%.

Purge and Trap Method for Determination of Volatile Halocarbons and Carbon Disulfide in Table-Ready Foods

1987 ◽  
Vol 70 (2) ◽  
pp. 215-226
Author(s):  
David L Heikes
Keyword(s):  
Gas Chromatography ◽  
Drinking Water ◽  
Carbon Disulfide ◽  
Gas Chromatography Mass Spectrometry ◽  
Electron Capture Detection ◽  
Purge And Trap ◽  
Photometric Detection ◽  
Methyl Chloroform ◽  
Volatile Halocarbons

Abstract A method developed for the determination of ethylene dibromide in table-ready foods has been modified and expanded to include 7 other volatile halocarbons and carbon disulfide. Samples are stirred with water and purged with nitrogen for 0.5 h in a water bath at 100°C. The analytes collected on a duplex trap composed of Tenax TA and XAD-4 resin are eluted with hexane and determined by gas chromatography with electron capture detection or Hall electrolytic conductivity detection. Flame photometric detection in the sulfur mode is used to determine carbon disulfide. Thick-film, wide-bore capillary columns are used exclusively in both the determination and confirmation of the halogenated analytes. The higher levels of analytes are also confirmed by full scan gas chromatography mass spectrometry (GC/MS). Samples are analyzed for carbon disulfide, methylene chloride, chloroform, 1,2-dichloroethane, methyl chloroform, carbon tetrachloride, trichloroethylene, 1,2-dibromoethane, and tetrachloroethylene. Initially, 19 table-ready foods from the Food and Drug Administration's Total Diet Study were analyzed by this method. A limited survey of those food items exhibiting high levels of analytes was conducted. Samples exhibited levels up to 3300 ppb (methyl chloroform in Parmesan cheese). Recoveries of all 9 analytes from fortified samples ranged from 83 to 104%. Chromatograms from this purge and trap method are clean, enabling quantitation levels of low parts per billion and sub-parts per billion to be achieved for the halogenated analytes. The quantitation limit for carbon disulfide is 12 ppb. Two compounds found in drinking water were identified by GC/MS as bromodichloromethane and chlorodibromomethane. Drinking water from several cities was analyzed for these trihalomethanes as well as for bromoform. Levels of up to 17 ppb bromodichloromethane were found. Recoveries ranged from 96 to 103%.

scholarly journals Sensitive determination of impurities in samples of vodka by gas chromatography with flame-ionization detection

2015 ◽  
pp. 3
Author(s):  
Nassiba Baimatova ◽  
Olga Demyanenko ◽  
Ahmad Zia
Keyword(s):  
Gas Chromatography ◽  
Direct Analysis ◽  
Alcoholic Beverages ◽  
Inlet Temperature ◽  
Flame Ionization Detection ◽  
Negative Consequences ◽  
Ionization Detection ◽  
Flame Ionization ◽  
Wide Range

<p>Vodka is one of the most popular alcoholic drinks around the world. Adulteration of vodkas lead to many negative consequences. A number of analytical methods covers a wide range of analytes and allows detection of adulterated alcoholic beverages, however, most of these methods are very labor and time consuming or require expensive analytical instrumentation. The simplest and thus most popular method is based on direct analysis by gas chromatography (GC) with flame-ionization detection (FID). The main drawback of this method for discovery of adulterated vodka samples is insufficient sensitivity. The aim of this study was to increase sensitivity of the method for determination of key vodka impurities. Optimized parameters included split ratio 10:1, inlet temperature &gt;120 °C, initial oven temperature 60 °C, flow rates of make-up gas, air and hydrogen 50, 400 and 40 mL/min, respectively. Obtained calibration plots are linear in the concentration range between 1 and 1000 mg/L with approximation coefficients R<sup>2</sup>&gt;0.99. Compared to a standard method, slope factors are about 4 times higher when optimized method is used proving its higher sensitivity.</p>

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