scholarly journals Determination of Multiresidue Pesticides in Green Tea by Using a Modified QuEChERS Extraction and Ion-Trap Gas Chromatography/Mass Spectrometry

2010 ◽  
Vol 93 (4) ◽  
pp. 1169-1179 ◽  
Author(s):  
David Steiniger ◽  
Guiping Lu ◽  
Jessie Butler ◽  
Eric Phillips ◽  
Yolanda Fintschenko
Keyword(s):  
Pesticide Residues ◽  
Ion Trap ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
The European Union ◽  
Modified Quechers ◽  
Maximum Residue Limits ◽  
Dispersive Spe ◽  
Multiresidue Pesticide Analysis

Abstract The pesticide residues in exported and imported tea products must not exceed the maximum residue limits (MRLs) regulated by the import countries. Tea is a complex matrix that obfuscates the determination of pesticide residues. Many available methods for multiresidue pesticide analysis of tea are time-consuming and require many cleanup steps. The objective of this study was to develop a simple multiresidue method by using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction and ion-trap GC/MS/MS, which can identify, confirm, and quantify pesticides in complex matrixes. A tea product was homogenized with water, and the pesticides were extracted with acetonitrile containing 1 acetic acid. The extract was subjected to centrifugation, initial cleanup with dispersive SPE (dSPE), solvent exchange, and final cleanup with dSPE. Diethyl-d10-parathion and triphenyl phosphate were used as the internal standard and surrogate, respectively. The final extract was injected into an ITQ 700 gas chromatograph/mass spectrometer. Quantitation of individual pesticides was based on matrix-matched calibration curves with a correlation coefficient of >0.9930 for the 22 pesticides selected for the study. The recoveries of the 22 pesticides ranged from 78 to 115, except those for diazinon (130) and malathion (122), with an average RSD of 8.7. The LOD values of all of the pesticides, except for terbufos, were below the MRLs set by the European Union and Japan.

scholarly journals Determination of Levels of Organochlorine, Organophosphorus, and Pyrethroid Pesticide Residues in Vegetables from Markets in Dar es Salaam by GC-MS

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
John A. M. Mahugija ◽  
Farhat A. Khamis ◽  
Esther H. J. Lugwisha
Keyword(s):  
Public Health ◽  
Mass Spectrometry ◽  
Pesticide Residues ◽  
Dar Es Salaam ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrethroid Pesticide ◽  
Maximum Residue Limits ◽  
Samples And Sampling ◽  
Dar Es Salaam City

This study investigated the levels of pesticides and metabolites in vegetables from major markets in Dar es Salaam city, Tanzania. Samples of fresh cabbage, spinach, and onions from the markets were analysed for pesticide residues. Extraction was performed using acetone followed by dichloromethane : cyclohexane mixture and the extracts were cleaned up using Florisil. The compounds were determined by gas chromatography-mass spectrometry (GC-MS). Pesticides and metabolites were detected in 72.2% of the samples. The detected pesticide residues and their highest mean concentrations were p,p′-DDT 4.00 × 10−3 mg/kg, p,p′-DDD 6.40 × 10−1 mg/kg, o,p′-DDD 1.00 × 10−2 mg/kg, α-endosulfan 6.00 × 10−1 mg/kg, β-endosulfan 2.10 × 10−1 mg/kg, chlorpyrifos 3.00 mg/kg, and cypermethrin 4.00 × 10−2 mg/kg. The most frequently detected compounds were p,p′-DDD and chlorpyrifos. The order of contamination was spinach > cabbage > onions. Generally, there were no significant variations in concentrations of pesticide residues among samples and sampling sites, which indicated similarities in contamination patterns. The concentrations of contaminants were above the maximum residue limits (MRLs) in 33.3–50% of the samples. The findings indicated risks and concerns for public health.

Determination of Carbadox-Related Residues in Swine Liver by Gas Chromatography/Mass Spectrometry with Ion Trap Detection

1991 ◽  
Vol 74 (4) ◽  
pp. 611-618 ◽  
Author(s):  
Martin J Lynch ◽  
Franklyn R Mosher ◽  
Richard P Schneider ◽  
Hassan G Fouda ◽  
James E Risk
Keyword(s):  
Chemical Ionization ◽  
Ion Trap ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Isotope Dilution Analysis ◽  
Gas Chromatograph ◽  
Porcine Liver ◽  
Methyl Ester Derivative ◽  
Swine Liver

Abstract The Ion trap detector (ITD), in combination with a capillary gas chromatograph and under chemical ionization conditions, offers sufficient sensitivity to determine carbadoxrelated residues as the methyl ester derivative of quinoxaline- 2-carboxylic acid at 3 μg/kg or higher in porcine liver. A tetradeuterated internal standard of QME effectively compensates for losses incurred during sample preparation. The method produced mean levels of 3.3 (±0.5), 5.5 (±0.8), and 10.1 (±0.9) μg/kg for liver fortified at 3, 5, and 10 μg/kg. When applied to analysis of samples containing incurred residues of 14C-carbadox at the low μg/kg level, results were comparable to those obtained by reverse isotope dilution analysis.

Determination of Linuron in Potatoes Using Capillary Column Gas Chromatography/Mass Spectrometry

1989 ◽  
Vol 72 (6) ◽  
pp. 970-974
Author(s):  
Gregory C Mattern ◽  
George M Singer ◽  
Judy Louis ◽  
Mark Robson ◽  
Joseph D Rosen
Keyword(s):  
Gas Chromatography ◽  
Ion Trap ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Gas Chromatography Mass Spectrometry ◽  
Phenylurea Herbicides ◽  
Ionization Mode ◽  
Capillary Column Gas Chromatography ◽  
Ppm Level

Abstract A convenient method for the determination of the JV-methyl,iVmethoxy- phenylurea herbicide (linuron) in potatoes has been developed. The herbicide is extracted from potatoes using a slightly modifled Luke multiresidue procedure. The extract is analyzed directly by gas chromatography with cold on-column injection, using an ion trap mass spectrometer in the chemical ionization mode as the detector. Quantitation is performed using p-bromonitrobenzene as the internal standard. The limit of detection is 0.1 ppm. Recoveries of linuron in potatoes averaged 112 ± 6% at the 0.5 ppm level, and 110 ± 2% at the 0.2 ppm level. No linuron residues were found in 25 potato samples that were analyzed by this method. Two other iV-methyl,iV-methoxyphenylurea herbicides, metobromuron and chlorbromuron, are also sufficiently stable to be determined by this method, but the N,Ndialkyl- phenylurea herbicides neburon, diuron, and monuron are too thermally unstable and degrade in the gas chromatograph.

scholarly journals Fast and Easy Multiresidue Method Employing Acetonitrile Extraction/Partitioning and “Dispersive Solid-Phase Extraction” for the Determination of Pesticide Residues in Produce

2003 ◽  
Vol 86 (2) ◽  
pp. 412-431 ◽  
Author(s):  
Michelangelo Anastassiades ◽  
Steven J Lehotay ◽  
Darinka Štajnbaher ◽  
Frank J Schenck
Keyword(s):  
Solid Phase Extraction ◽  
Pesticide Residues ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Residual Water ◽  
Phase Extraction ◽  
Dispersive Solid Phase Extraction ◽  
Wide Range ◽  
Dispersive Spe

Abstract A simple, fast, and inexpensive method for the determination of pesticide residues in fruits and vegetables is introduced. The procedure involves initial single-phase extraction of 10 g sample with 10 mL acetonitrile, followed by liquid–liquid partitioning formed by addition of 4 g anhydrous MgSO4 plus 1 g NaCl. Removal of residual water and cleanup are performed simultaneously by using a rapid procedure called dispersive solid-phase extraction (dispersive-SPE), in which 150 mg anhydrous MgSO4 and 25 mg primary secondary amine (PSA) sorbent are simply mixed with 1 mL acetonitrile extract. The dispersive-SPE with PSA effectively removes many polar matrix components, such as organic acids, certain polar pigments, and sugars, to some extent from the food extracts. Gas chromatography/mass spectrometry (GC/MS) is then used for quantitative and confirmatory analysis of GC-amenable pesticides. Recoveries between 85 and 101% (mostly >95%) and repeatabilities typically <5% have been achieved for a wide range of fortified pesticides, including very polar and basic compounds such as methamidophos, acephate, omethoate, imazalil, and thiabendazole. Using this method, a single chemist can prepare a batch of 6 previously chopped samples in <30 min with approximately $1 (U.S.) of materials per sample.

scholarly journals Validation of a Fast and Easy Method for the Determination of Residues from 229 Pesticides in Fruits and Vegetables Using Gas and Liquid Chromatography and Mass Spectrometric Detection

2005 ◽  
Vol 88 (2) ◽  
pp. 595-614 ◽  
Author(s):  
Steven J Lehotay ◽  
André de Kok ◽  
Maurice Hiemstra ◽  
Peter van Bodegraven
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Fruits And Vegetables ◽  
Ion Trap ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Easy Method ◽  
Wide Range ◽  
Dispersive Spe

Abstract Validation experiments were conducted of a simple, fast, and inexpensive method for the determination of 229 pesticides fortified at 10–100 ng/g in lettuce and orange matrixes. The method is known as the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for pesticide residues in foods. The procedure involved the extraction of a 15 g sample with 15 mL acetonitrile, followed by a liquid–liquid partitioning step performed by adding 6 g anhydrous MgSO4 plus 1.5 g NaCl. After centrifugation, the extract was decanted into a tube containing 300 mg primary secondary amine (PSA) sorbent plus 1.8 g anhydrous MgSO4, which constituted a cleanup procedure called dispersive solid-phase extraction (dispersive SPE). After a second shaking and centrifugation step, the acetonitrile extract was transferred to autosampler vials for concurrent analysis by gas chromatography/mass spectrometry with an ion trap instrument and liquid chromatography/tandem mass spectrometry with a triple quadrupole instrument using electrospray ionization. Each analytical method was designed to analyze 144 pesticides, with 59 targeted by both instruments. Recoveries for all but 11 of the analytes in at least one of the matrixes were between 70–120% (90–110% for 206 pesticides), and repeatabilities typically <10% were achieved for a wide range of fortified pesticides, including methamidophos, spinosad, imidacloprid, and imazalil. Dispersive SPE with PSA retained carboxylic acids (e.g., daminozide), and <50% recoveries were obtained for asulam, pyridate, dicofol, thiram, and chlorothalonil. Many actual samples and proficiency test samples were analyzed by the method, and the results compared favorably with those from traditional methods.

scholarly journals Modified QuEChERS Extraction and HPLC-MS/MS for Simultaneous Determination of 155 Pesticide Residues in Rice (Oryza sativa L.)

Foods ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 18
Author(s):  
Maria Graça Melo ◽  
Ana Carqueijo ◽  
Andreia Freitas ◽  
Jorge Barbosa ◽  
Ana Sanches Silva
Keyword(s):  
Oryza Sativa ◽  
Pesticide Residues ◽  
High Performance ◽  
Oryza Sativa L ◽  
The European Union ◽  
Limit Of Quantification ◽  
Factors Affecting ◽  
Triple Quadrupole Instrument ◽  
Modified Quechers

Rice (Oryza sativa L.) is the staple food of more than half of the world’s population. The main factors affecting the quality of rice include grain length, texture, stickiness, flavor, and aroma. Pesticides are intended for the protection of plant products from weeds, fungi, or insects. However, pesticides also result in negative effects such as environment disturbances, pest resistance and toxicity to both users and food consumers. The aim of this study was to conduct validation experiments of a method for the determination of multi-pesticides in rice, a model food of other cereals. A quick, easy, cheap, effective, rugged, and safe (QuEChERS) method was used for the extraction of pesticide residues from rice followed by high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) with a triple quadrupole instrument using electrospray ionization. The analytical method has chromatography-tandem according to SANTE/11813/2017. The limit of quantification was 5 μg/kg. Recoveries for the 155 analyzed pesticides ranged between 77.1% for pirimiphos-ethyl and 111.5% for flutriafol and they were determined at 3 spiking levels. The proposed method was demonstrated to be quick, simple, precise, and accurate and allowed for evaluating the compliance of cereals samples with legislated maximum residue levels of pesticides in the European Union.

scholarly journals Validation and Uncertainty Analysis of a Multiresidue Method for 67 Pesticides in Made Tea, Tea Infusion, and Spent Leaves Using Ethyl Acetate Extraction and Gas Chromatography/Mass Spectrometry

2010 ◽  
Vol 93 (2) ◽  
pp. 411-424 ◽  
Author(s):  
Bappaditya Kanrar ◽  
Sudeb Mandal ◽  
Anjan Bhattacharyya
Keyword(s):  
Graphitized Carbon Black ◽  
Gas Chromatography Mass Spectrometry ◽  
The European Union ◽  
Tea Infusion ◽  
Multiresidue Method ◽  
Graphitized Carbon ◽  
Maximum Residue Limits ◽  
The Matrix ◽  
Primary Secondary Amine ◽  
Dispersive Spe

Abstract A rapid, specific, and sensitive multiresidue method to determine 67 pesticides in made tea, tea infusion, and spent leaves was developed and validated for routine analysis by GC/MS with an approximately 29 min GC run time. The method was reproducible (HorRat <0.5 at 50 ng/g) when validated at 50 and 100 ng/g. The samples were extracted with ethyl acetatecyclohexane (9 + 1, v/v), and the extracts were cleaned up by dispersive SPE with primary-secondary amine sorbent + graphitized carbon black + Florisil. The recoveries of all the pesticides were within 70120 with an RSD of <20 at 50 ng/g and R2 > 0.99. The matrix effect on the signals of the compounds was corrected by using matrix-matched calibration standards. The LOQ met the requirements of the maximum residue limits for pesticides in tea as recommended by the European Union.

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