Simple Analytical Method for Organophosphorus Pesticide Determination in Unpolished Rice, Using Removal of Fats by Zinc Acetate

1984 ◽  
Vol 67 (4) ◽  
pp. 798-800
Author(s):  
Kazuhiko Adachi ◽  
Nobuyuki Ohokuni ◽  
Takao Mitsuhashi
Keyword(s):  
Activated Charcoal ◽  
Zinc Acetate ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Chromatographic Column ◽  
Simple Method ◽  
Rice Samples ◽  
Higher Fatty Acids ◽  
Unpolished Rice

Abstract A rapid and simple method is developed for the determination of organophosphorus pesticides in unpolished rice. The new method incorporated acetonitrile-water (1 + 1) extraction, removal of fats by zinc acetate, and further cleanup on an activated charcoal chromatographic column. The higher fatty acids in the extract react rapidly with zinc acetate to form insoluble zinc carboxylates, which precipitate. Additional interferences were cleaned up on an activated charcoal chromatographic column, and organophosphorus pesticides adsorbed on the activated charcoal were eluted with acetone-hexane. Dimethoate is not retained on the activated charcoal and must be extracted with dichloromethane from the first acetonitrile-water eluate. Pesticides are measured by flame photometric gas chromatography. Recoveries from 50 g unpolished rice samples fortified with 5-50 μg diazinon, 6-30 μg parathion, 8-40 μg fenitrothion and IBP, 10-50 μg dimethoate and fenthoate, 20-100 μg malathion, or 40-200 μg EPN ranged from 75.7 to 95.8%.

Comparative Study of Methods for the Extraction of Eleven Organophosphorus Pesticide Residues in Rice

1975 ◽  
Vol 58 (6) ◽  
pp. 1286-1293
Author(s):  
Yoichi Aoki ◽  
Mitsuharu Takeda ◽  
Mitsuru Uchiyama
Keyword(s):  
Analytical Method ◽  
Pesticide Residues ◽  
Organophosphorus Pesticides ◽  
Stationary Phases ◽  
Organophosphorus Pesticide ◽  
Extraction Methods ◽  
Rice Samples ◽  
Liquid Chromatographic ◽  
Unpolished Rice

Abstract Several extraction methods are compared for the simultaneous analysis of organophosphorus pesticides in unpolished rice. Four stationary phases were used for the subsequent gas-liquid chromatographic (GLC) determination of the selected pesticides. Using 3 different GLC columns, 11 pesticides were completely separated and identified. The efficiency of the cleanup and the sensitivity of the analytical method were evaluated by using powdered unpolished rice samples fortified with the pesticides and also wheat and dried bean samples. Average recoveries ranged from 74.7% for disulfoton to 97.4% for malathion in unpolished rice and from 68.1% for disulfoton to 108.3% for malathion in other crops. The method described is applicable to the analysis of selected organophosphorus pesticide residues in unpolished rice, wheat, buckwheat, and dried beans.

scholarly journals Comparison of Cleanup Techniques for Simple Method for Analysis of Selected Organophosphorus Pesticide Residues in Molluscs

1996 ◽  
Vol 79 (1) ◽  
pp. 123-131 ◽  
Author(s):  
Félix Hernández ◽  
Roque Serrano ◽  
Joaquim Beltran ◽  
Francisco J López
Keyword(s):  
Silica Gel ◽  
Column Chromatography ◽  
Pesticide Residues ◽  
High Speed ◽  
Mytilus Galloprovincialis ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Gas Chromatograph ◽  
Simple Method

Abstract A simple method for determination of 5 organo phosphorus pesticides (dimethoate, chlorfenvin phos, chlorpyrifos, methidathion, and phosmet) in molluscs (Mytilus galloprovincialis and Venus gallina) was developed, with special attention to cleanup. Organophosphorus pesticides were extracted with acetonitrile-acetone (90 + 10, v/v) in a high-speed blender. Two cleanup procedures were used to defat extracts prior to injection into a gas chromatograph: liquid-liquid partition with acetoni trile-hexane and adsorption column chromatography with silica gel. The latter was more efficient for elimination of fat and fractionation of pesticides with different polarities. Limits of detection of the overall procedure including extraction and cleanup ranged from 0.2 to 1 ng/g. Quantitative recoveries for pesticide concentrations ranging from 1 to 10 000 ng/g were obtained.

Simple Analytical Method for Organophosphorus Pesticide Residues in Milk

1990 ◽  
Vol 73 (5) ◽  
pp. 770-772
Author(s):  
Masatake Toyoda ◽  
Kazuhiko Adachi ◽  
Tadakazu Ida ◽  
Katsuhiko Noda ◽  
Norio Minagawa
Keyword(s):  
Pesticide Residues ◽  
Milk Fat ◽  
Capillary Column ◽  
Organophosphorus Pesticide ◽  
Simple Method ◽  
Coefficients Of Variation ◽  
Complete Study ◽  
The Mean ◽  
Capillary Column Gas Chromatography

Abstract A simple method for determination of organophosphorus pesticide residues at the parts per million level In milk was developed. Pesticide residues were extracted with acetonitrlle added to aqueous milk, fat was removed by zinc acetate addition and dichloromethane partition, and analytes were concentrated and analyzed by wide-bore capillary column gas chromatography. Recoveries of 6 pesticides spiked in milk samples at levels of 0.1 and 1.0 μg/mL were 82.1- 93.8% and 79.7-96.6%, respectively. Triplicate samples spiked with 6 pesticides at 1 itg/mL were analyzed independently by 3 laboratories. Average recoveries were greater than 80%, and the mean coefficients of variation for the complete study were 2.9% for diazlnon, 5.4% for dimethoate, 4.6% for malathlon, 4.6% for parathlon, 4.9% for EPN, and 6.1% for phosalone.

Optimization of Sweep Codistillation Apparatus for Determination of Coumaphos and Other Organophosphorus Pesticide Residues in Animal Fat

1987 ◽  
Vol 70 (3) ◽  
pp. 442-445
Author(s):  
Robert L Brown ◽  
Clinton N Farmer ◽  
Roderick G Millar
Keyword(s):  
Coefficient Of Variation ◽  
Pesticide Residues ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Optimum Conditions ◽  
Animal Fat ◽  
Sweep Time ◽  
Coefficients Of Variation ◽  
The Mean

Abstract Optimum conditions have been developed for the quantitative recovery of coumaphos from animal fat by using a commercial sweep codistillation unit. Under the conditions specified (255°C distillation temperature, 250 mL/min of nitrogen, 60 min sweep time) and using Florisil trapping, the mean recovery of coumaphos was 91% with a coefficient of variation of 6%. Other organophosphorus pesticides recovered include diazinon, chlorpyrifos, ethion, and bromophos-ethyl with recoveries ranging from 90 to 96% and coefficients of variation ranging between 4 and 6%.

scholarly journals Size Exclusion Chromatographic Cleanup for GC/MS Determination of Organophosphorus Pesticide Residues in Household and Vehicle Dust

2002 ◽  
Vol 85 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Thomas F Moate ◽  
Matthew Furia ◽  
Cynthia Curl ◽  
Juan F Muniz ◽  
Jianbo Yu ◽  
...  
Keyword(s):  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Fruit Production ◽  
Size Exclusion ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Size Exclusion Chromatographic ◽  
Tree Fruit ◽  
Exclusion Chromatography

Abstract Size exclusion chromatography (SEC) was used as a cleanup method for the analysis of organophosphorus pesticides in household and vehicle dusts. The pesticides investigated were diazinon, methyl parathion, chlorpyrifos, malathion, phosmet, and azinphosmethyl. These compounds are of interest due to their use in agricultural tree fruit production and/or urban pest control. Pesticides were determined via gas chromatography/mass spectrometry with selected-ion monitoring and cool on-column injection. The lower limit of method validation was 0.20 μg/g. Method limits of detection in dust ranged from 0.012–0.055 μg/g. Dust samples were collected with vacuums from the homes and vehicles of people living and working in a rural agricultural region in the central part of Washington State. The analytes were extracted from the dust by sonication in acetone. The extracts were solvent-exchanged to cyclohexane, frozen, thawed, and centrifuged prior to SEC injection. Following SEC, the eluent was split into 2 fractions, concentrated, and injected on-column into the gas chromatograph. This method represents the first complete publication describing the SEC cleanup of organophosphorus pesticides in dusts. Recoveries of pesticides in dusts ranged from 63.5–110.8 ± 4.9–19.6% over a fortification range of 0.20–10.00 μg/g. This optimized, automated, and reproducible SEC method does not require further treatment or cleanup for trace determination of these organophosphorus pesticides.

scholarly journals Multiresidue Determination of Organophosphorus Pesticides in Ginkgo Leaves by Accelerated Solvent Extraction and Gas Chromatography with Flame Photometric Detection

2005 ◽  
Vol 88 (3) ◽  
pp. 729-735
Author(s):  
Xionghai Yi ◽  
Yitong Lu
Keyword(s):  
Gas Chromatography ◽  
Solvent Extraction ◽  
Solid Phase ◽  
Organophosphorus Pesticides ◽  
Accelerated Solvent Extraction ◽  
Simple Method ◽  
Photometric Detection ◽  
Relative Standard ◽  
Flame Photometric Detection

Abstract A rapid and simple method using accelerated solvent extraction and solid-phase extraction cleanup was developed and validated for the determination of 15 organophosphorus pesticides in ginkgo leaves by capillary gas chromatography with flame photometric detection. The pesticides were extracted at 100°C under 1500 psi pressure in <20 min. The average recovery from 10 g ginkgo leaves, fortified at 3 levels ranging from 0.05 to 1.00 mg/kg, was 95.2% with a relative standard deviation of 4.6%. The limits of detection ranged from 1.11 × 10−3 mg/kg (dimethoate) to 4.44 × 10−3 mg/kg (dichlorvos). The proposed method showed acceptable accuracy and precision while minimizing environmental concerns, time, and labor. Furthermore, the method could be easily applied to the monitoring of these 15 organophosphorus pesticides in ginkgo leaves.

Highly-sensitive organophosphorus pesticide biosensors based on CdTe quantum dots and bi-enzyme immobilized eggshell membranes

The Analyst ◽  
2016 ◽  
Vol 141 (3) ◽  
pp. 1105-1111 ◽  
Author(s):  
Gao Xue ◽  
Zhao Yue ◽  
Zhang Bing ◽  
Tang Yiwei ◽  
Liu Xiuying ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Cdte Quantum Dots ◽  
Optical Biosensing ◽  
Highly Sensitive ◽  
Eggshell Membranes

An optical biosensing method using CdTe quantum dots (QDs) and bi-enzyme-immobilized eggshell membranes for the determination of organophosphorus pesticides (OPs) has been developed.

Selection of Enzyme Sources for Improved Sensitivity in Enzymatic Determination of Organophosphorus Pesticides

1982 ◽  
Vol 65 (6) ◽  
pp. 1297-1298
Author(s):  
Sana Udaya Bhaskar ◽  
Nanguneri V Nanda Kumar
Keyword(s):  
Lower Limit ◽  
Inverse Relationship ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Enzymatic Determination ◽  
Km Value ◽  
Menten Constant ◽  
Enzyme Source ◽  
Selection Of

Abstract The Michaelis-Menten constant (Km) for cholinesterases from different liver sources, the inhibitor concentration for 50% inhibition (I50), and the lower limit of estimation were determined for 3 organophosphorus pesticides and their oxygen analogs. Maximum sensitivity in organophosphorus pesticide determinations can be achieved by choosing the enzyme source which has a higher Km value. An inverse relationship is suggested between Km and the lower limit of estimation.

scholarly journals Determination of Organophosphorus Pesticide Residues in Milk

2013 ◽  
Vol 57 (2) ◽  
pp. 185-189 ◽  
Author(s):  
Tomasz Kiljanek ◽  
Alicja Niewiadowska ◽  
Stanisław Semeniuk
Keyword(s):  
Pesticide Residues ◽  
Solid Phase ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Gel Permeation Chromatography ◽  
Proficiency Tests ◽  
The European Union ◽  
Photometric Detection ◽  
Milk Samples

Abstract A method for simultaneous determination of 13 organophosphorus pesticide residues in milk samples has been developed and validated. The method is based on the extraction of the sample with acetone and petroleum ether, cleanup by gel permeation chromatography, and solid phase extraction, and determination by gas chromatography with flame photometric detection. The recovery, investigated by analysing blank milk samples spiked with azinphos, chlorfenvinphos, chlorpyrifos, chlorpyrifos-methyl, diazinon, fenitrothion, methacrifos, methidathion, parathion-methyl, pyrazophos, and triazophos at concentrations of 10, 20, and 30 μg/kg, and with parathion and pirimiphos-methyl at concentrations of 25, 50, and 75 μg/kg, ranged from 73.1% to 106.2%. Performance characteristics, such as repeatability and within-laboratory reproducibility expressed as coefficient of variation were less than 20%. Measurement uncertainty was lower than 22% for all validated organophosphorus pesticides. The limits of quantification were 10 μg/kg for all compounds and allowed determination of residues at, or even below, the maximum residue limits set by the European Union. The satisfactory z-score results of international proficiency tests confirm good accuracy, reproducibility, and reliability of the developed method.

Modified Storherr Method for Determination of Organophosphorus Pesticides in Nonfatty Food Total Diet Composites

1981 ◽  
Vol 64 (3) ◽  
pp. 714-719
Author(s):  
Louis J Carson
Keyword(s):  
Liquid Chromatography ◽  
Pesticide Residues ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Gas Liquid Chromatography ◽  
Flame Photometric Detector ◽  
Limit Of Quantitation ◽  
Total Diet ◽  
Residue Levels

Abstract The method of Storherr et al. for organophosphorus pesticide residues in nonfatty foods has been modified to permit its use in analyzing the composites of nonfatty foods in the Food and Drug Administration Total Diet Program. Modifications were designed to permit the examination by gas-liquid chromatography (GLC) of the larger weight (100 mg) of sample equivalent required by the Total Diet program. To achieve a limit of quantitation of 2 ppb parathion, the organophosphorus pesticides are determined by GLC equipped with flame photometric detector (P-mode) and/or KCl thermionic detector. Recovery data, ranging from 70 to 133%, are presented for fortification (2-10 ppb) of organophosphorus pesticides in 7 nonfatty food Total Diet composites. The modified Storherr method was successfully tested in an intralaboratory method trial of 2 Total Diet composites (potatoes and legumes) fortified at 5-13 ppb with malathion, parathion, paraoxon, and monocrotophos. In addition, the modified Storherr method was compared to existing FDA Total Diet methodology for the determination of incurred organophosphorus residues. Residue levels found by both methods were similar for malathion (30 ppb), parathion (7 ppb), and diazinon (1 ppb), but only the modified Storherr method was capable of determining about 10 ppb dimethoate and phorate in the cereals and grains composite.

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