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.

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%.

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 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.

Gas-Liquid Chromatographic Determination of Chloramphenicol in Agricultural Crops

1976 ◽  
Vol 59 (5) ◽  
pp. 1118-1121
Author(s):  
Kumiko Sasaki ◽  
Mitsuharu Takeda ◽  
Mitsuru Uchiyama
Keyword(s):  
Silicic Acid Column ◽  
Stationary Phases ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Gas Liquid Chromatography ◽  
Agricultural Crops ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic ◽  
Unpolished Rice

Abstract A method is presented for the gas-liquid chromatographic determination of chloramphenicol in agricultural crops. Chloramphenicol is extracted with ethyl acetate, cleaned up by silicic acid column chromatography, acetylated with acetic anhydride and pyridine, and then measured by gas-liquid chromatography with electron capture detection. Two stationary phases, DEGS + phosphoric acid and Reoplex 400, were used. The sensitivity was ca 8 ng (40% full scale deflection). The efficiency of the analytical method was evaluated by analyzing crops fortified with chloramphenicol. The average recovery ranged from 72% in unpolished rice to 86% in Chinese radishes.

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.

Gas-Liquid Chromatographic Determination of Technical Chlordane Residues in Food Crops: Interpretation of Analytical Data

1975 ◽  
Vol 58 (5) ◽  
pp. 1051-1061
Author(s):  
William P Cochrane ◽  
James F Lawrence ◽  
Young W Lee ◽  
Ronald B Maybury ◽  
Brian P Wilson
Keyword(s):  
Field Experiments ◽  
Stationary Phases ◽  
Analytical Data ◽  
Chromatographic Determination ◽  
Electron Capture Detection ◽  
Food Crops ◽  
Liquid Chromatographic Determination ◽  
Consistent Method ◽  
Liquid Chromatographic

Abstract An interlaboratory investigation of technical chlordane residues in food crops was carried out to determine the most practical and consistent method of reporting results. Using a technical chlordane reference standard, 8 gas chromatographic stationary phases were studied for their resolution capabilities. The best separations were obtained with SE-30 and its OV-1 equivalent. Using these columns and electron capture detection, potatoes and carrots from supervised field experiments were analyzed in duplicate and quantitated by using 4 methods of calculation. The data were statistically treated to determine the precision and bias for each method. Also, 1 sample was analyzed in duplicate on 2 different occasions by 6 laboratories to substantiate the initial conclusions. Based on the criterion of high precision it is suggested that a comparison of total area under the chromatogram of the sample with total area of a standard technical chlordane be the method of quantitation. Only peaks which are common to both standard and sample have any significance in this type of calculation.

scholarly journals Quantification of Fructans in Bioethanol Stillage Based On a Simplified Analytical Method

2021 ◽  
Author(s):  
Andreas Zimmermann ◽  
Martin Kaltschmitt
Keyword(s):  
Analytical Method ◽  
Measurement Errors ◽  
Process Development ◽  
Stationary Phases ◽  
New Approach ◽  
Sample Matrix ◽  
Sample Throughput ◽  
Complex Sample ◽  
Potential Substrate

Abstract Bioethanol stillage, the main by-product of industrial bioethanol production, is a potential substrate for fructans. However, the determination and quantification of fructans in such complex sample matrices is still a challenge for the corresponding analytics to be overcome in order to allow for the identification and utilisation of such unused fructan sources. Especially a possible utilisation or rather the corresponding process development requires appropriate analytics first. Thus, this paper aims to illuminate the basics of fructan quantification in stillage and the corresponding challenges particularly arising with widely used HPLC-RID systems. On this basis, a new approach for fructan quantification is presented based on such HPLC-RID systems allowing for a reliable and especially simple fructan determination in bioethanol stillage for comparably high sample throughput. The developed method performs fructan quantification by determination of fructose and glucose equivalents after a targeted acidic hydrolysis adapted to the respective sample matrix. By means of two different stationary phases, the problem of limited resolution in case of HPLC-RID is overcome and thus measurement errors are reduced. The approach towards the adapted analytical method can be transferred easily to comparable complex sample matrices.

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