scholarly journals Simultaneous Determination of Benzene and Toluene in Pesticide Emulsifiable Concentrate by Headspace GC-MS

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Lidong Cao ◽  
Hua Jiang ◽  
Jing Yang ◽  
Li Fan ◽  
Fengmin Li ◽  
...  
Keyword(s):  
Simultaneous Determination ◽  
Internal Standard ◽  
Fused Silica ◽  
Gas Chromatography Mass Spectrometry ◽  
Equilibration Time ◽  
Emulsifiable Concentrate ◽  
Pesticide Formulations ◽  
Relative Standard ◽  
Standard Additions

The toxic inert ingredients in pesticide formulations are strictly regulated in many countries. In this paper, a simple and efficient headspace-gas chromatography-mass spectrometry (HSGC-MS) method using fluorobenzene as an internal standard (IS) for rapid simultaneous determination of benzene and toluene in pesticide emulsifiable concentrate (EC) was established. The headspace and GC-MS conditions were investigated and developed. A nonpolar fused silica Rtx-5 capillary column (30 m×0.20 mmi.d. and 0.25 μm film thickness) with temperature programming was used. Under optimized headspace conditions, equilibration temperature of 120°C, equilibration time of 5 min, and sample size of 50 μL, the regression of the peak area ratios of benzene and toluene to IS on the concentrations of analytes fitted a linear relationship well at the concentration levels ranging from 3.2 g/L to 16.0 g/L. Standard additions of benzene and toluene to blank different matrix solutions 1ead to recoveries of 100.1%–109.5% with a relative standard deviation (RSD) of 0.3%–8.1%. The method presented here stands out as simple and easily applicable, which provides a way for the determination of toxic volatile adjuvant in liquid pesticide formulations.

scholarly journals Development and validation of a GC–MS method for the simultaneous determination of acetochlor, fluorochloridone, and pendimethalin in a herbicide emulsifiable concentrate formulation

2020 ◽  
Vol 32 (4) ◽  
pp. 238-241 ◽  
Author(s):  
Dandan Wang ◽  
Shengde Wu
Keyword(s):  
Internal Standard ◽  
Ternary Mixtures ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Limit Of Quantification ◽  
Emulsifiable Concentrate ◽  
Relative Standard ◽  
Replicate Measurements ◽  
Development And Validation

This paper describes a rapid method to simultaneously determine acetochlor, fluorochloridone and pendimethalin present in a herbicide emulsifiable concentrate (EC) formulation using gas chromatography–mass spectrometry (GC–MS). Selected ion monitoring mode was performed to increase the sensitivity, with dibutyl phthalate as an internal standard. The method was validated with respect to linearity, accuracy, precision, and stability. Chromatographic separation was carried out on a TG-5 MS column (30 m × 0.25 mm × 0.25 μm) with helium as the carrier gas at a flow rate of 1.0 mL/min. Calibration curves were linear over 2.0–20.0 μg/mL for each analyte, and the limit of quantification was below 20 ng/mL. Good performance in terms of recovery ranging from 94.5% to 102.5% at 3 concentration levels proved excellent accuracy. The intra- and inter-day relative standard deviations for 6 replicate measurements were always less than 5%. The developed method is simple and efficient for the routine determination of the ternary mixtures in a compound herbicide EC formulation product.

Simultaneous determination of furan and its derivatives in food by headspace gas chromatography-mass spectrometry (HS-GC-MS)

2021 ◽  
Vol 4 (3) ◽  
pp. 13-23
Author(s):  
Ha Binh Nguyen Thi ◽  
Cao Tien Bui ◽  
Ngoc Anh Mai Thi ◽  
Hoai Pham Thi ◽  
Hong Hao Le Thi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Internal Standard ◽  
Food Samples ◽  
Gas Chromatography Mass Spectrometry ◽  
Powdered Milk ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard

A method for the simultaneous determination of furans, 2-methylfuran and 3-methylfuran in some food by gas chromatography-mass spectrometry (GC-MS) has successfully developed. Analysed samples were treated by a headspace technique using furan-d4 as an internal standard. The detection limit of the method is 0.3 µg/kg, the quantitative limit of the method is 1.0 µg/kg. The recovery of the method is in the range of 72 to 110%. The relative standard deviation ranges from 3.3 to 13%. The method was applied to analyze 100 food samples, including: coffees, canned meats, baby foods, powdered milk. The results showed that furans, 2-methylfuran, 3-methylfuran were detected in 30 samples out of 100 collected samples. In particular, furans were found in a ranges of 5.7 to 2803 µg/kg in all of coffee samples, including instant coffee and roasted coffee. In addition, furans were detected in one baby food sample contains, furans and 2-methylfuran in four canned meat samples, and no furans milk were detected in powder sample among 25 analysed samples.

scholarly journals Development, Optimization, and Comparison of Different Sample Pre-Treatments for Simultaneous Determination of Vitamin E and Vitamin K in Vegetables

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2509
Author(s):  
Antonella Aresta ◽  
Gualtiero Milani ◽  
Maria Lisa Clodoveo ◽  
Carlo Franchini ◽  
Pietro Cotugno ◽  
...  
Keyword(s):  
Vitamin E ◽  
Simultaneous Determination ◽  
Vitamin K ◽  
Solid Phase ◽  
Internal Standard ◽  
Premature Aging ◽  
Tocopheryl Acetate ◽  
Gas Chromatography Mass Spectrometry ◽  
Target Analytes

The absence of vitamin E from the diet can lead to cardiovascular disease, cancer, cataracts, and premature aging. Vitamin K deficiency can lead to bleeding disorders. These fat-soluble vitamins are important nutritional factors that can be determined in different methods in vegetables. In this work, the simultaneous determination of α-tocopherol, α-tocopheryl acetate, phylloquinone, and menaquinone-4 by gas chromatography–mass spectrometry (GC–MS) has been optimized using both direct injection and solid phase microextraction (SPME). Three different sample pre-treatment approaches based on: (A) solid–liquid–liquid–liquid extraction (SLE–LLE), (B) SLE, and (C) SPME were then applied to extract the target analytes from vegetables samples using menaquinone as internal standard. All the procedures allowed the determination of the target analytes in onion, carrot, celery, and curly kale samples. Similar results were obtained with the three different approaches, even if the one based on SPME offers the best performance, together with a reduced use of solvent, time consumption, and experimental complexity, which makes it the preferable option for industrial applications.

scholarly journals UPLC–MS/MS simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, MDMA, and MDA in hair

2020 ◽  
Vol 32 (2) ◽  
pp. 145-148 ◽  
Author(s):  
Siyuan Chen ◽  
Jianshe Ma ◽  
Xianqin Wang ◽  
Peiwu Geng
Keyword(s):  
Simultaneous Determination ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
Correlation Coefficients ◽  
Ammonium Hydroxide ◽  
Ultra Performance Liquid Chromatography ◽  
Acetate Solution ◽  
Hair Samples ◽  
Relative Standard

Hair is a stable specimen and has a longer detection window (from weeks to months) than blood and urine. Through the analysis of hair, the long-term information of the drug use of the identified person could be explored. Our work is to establish an ultra-performance liquid chromatography–tandem mass spectroscopy (UPLC–MS/MS) method for simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyamphetamine (MDA) in hair. Methoxyphenamine was used as an internal standard. The chromatographic separation was performed on a UPLC ethylene bridged hybrid (BEH) C18 (2.1 mm × 50 mm, 1.7 μm) column using a mobile phase of acetonitrile–water with 10 mmol/L ammonium acetate solution which containing 0.05% ammonium hydroxide. The multiple reaction monitoring in positive electrospray ionization was used for quantitative determination. The intra-day and inter-day precisions (relative standard deviation [RSD]) were below 15%. The accuracy ranged between 85.5% and 110.4%, the average recovery rate was above 72.9%, and the matrix effect ranged between 92.7% and 109.2%. Standard curves were in the range of 0.05–5.0 ng/mg, and the correlation coefficients were greater than 0.995. The established UPLC–MS/MS method was applied to analyze the hair samples successfully.

Gas Chromatographic-Mass Spectrometric Determination of Epoxidized Soybean Oil Contamination of Foods by Migration from Plastic Packaging

1988 ◽  
Vol 71 (6) ◽  
pp. 1183-1186 ◽  
Author(s):  
Laurence Castle ◽  
Matthew Sharman ◽  
John Gilbert
Keyword(s):  
Fatty Acid ◽  
Soybean Oil ◽  
Lipid Extraction ◽  
Internal Standard ◽  
Epoxidized Soybean Oil ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Pvc Film ◽  
Relative Standard

Abstract A method for the quantitative determination of epoxidized soybean oil (ESBO) in foods is described. The procedure involves addition of a diepoxidized fatty acid ester internal standard, followed by lipid extraction from the food and transmethylation under basic conditions. Without further cleanup, the methylated fatty acid epoxides are derivatized to form 1,3-dioxolanes, which are then determined by capillary gas chromatography-mass spectrometry with selected ion monitoring. A detection limit of 2.0 mg/kg of epoxidized soybean oil in foods and a relative standard deviation of 7% have been achieved routinely. The method has been applied successfully to the analysis of cheeses, sandwiches, cakes, and microwave-cooked meals which have been contaminated with ESBO by migration from PVC film.

Gas Chromatographic Determination of Metolachlor in Pesticide Formulations: Collaborative Study

1985 ◽  
Vol 68 (3) ◽  
pp. 570-572
Author(s):  
Thomas G Gale ◽  
Arthur H Hofberg
Keyword(s):  
Active Ingredient ◽  
Collaborative Study ◽  
Internal Standard ◽  
Chromatographic Determination ◽  
Matched Pair ◽  
Emulsifiable Concentrate ◽  
Flame Ionization ◽  
Pesticide Formulations ◽  
Better Than

Abstract A gas chromatographic (GC) procedure for the determination of metolachlor in emulsifiable concentrate formulations containing about 76% active ingredient was collaboratively studied using the matched pair scheme. Metolachlor was extracted from the formulation with acetone containing dipentyl phthalate as the internal standard, chromatographed on OV-101, and detected by flame ionization. Determinations on the 4 samples by 21 government, university, and industrial collaborators using peak area measurements showed within-laboratory repeatability of better than 0.5%. Reproducibility was better than 1% for the formulation. The method has been adopted official first action.

Evaluation and interlaboratory validation of a GC-MS method for analysis of pesticide residues in teas

2007 ◽  
Vol 61 (1) ◽  
pp. 1-5 ◽  
Author(s):  
C. Peng ◽  
H. Kuang ◽  
X. Li ◽  
C. Xu
Keyword(s):  
Simultaneous Determination ◽  
Pesticide Residues ◽  
Graphitized Carbon Black ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
External Standard Method ◽  
Relative Standard ◽  
Interlaboratory Validation ◽  
Acetone Hexane

AbstractA method was described for simultaneous determination of nine organic heterocyclic pesticide residues by gas chromatography-mass spectrometry-selected ion monitoring. Atrazine, vinclozolin, procymidone, triflumizole, imazalil, buprofezin, propiconazole, fenarimol, and pyridaben were clearly separated from each other, extracted with acetone—hexane mixture, purified with graphitized carbon black cartridge and neutral Al2O3 cartridge, eluted with acetone—hexane mixture, simultaneously determined by GC-MS, and then quantified with an external standard method. Recoveries of pesticides ranged from 73 % to 116 % at the spiked level of 0.01–30 mg kg−1, while the relative standard deviation was between 3 % and 27 %. In addition, the limits of determination (0.01 mg kg−1 to 5.0 mg kg−1) and linearity (0.02–40 μg mL−1) revealed that simultaneous determination of multi-residues in Chinese teas (like Oolong tea, green tea, red tea, etc.) was possible. Furthermore, an interlaboratory study among 5 labs was conducted to further validate the method, and the results were satisfactory.

scholarly journals Rapid Simultaneous Determination of 43 Pesticide Residues in Schizonepeta tenuifolia by Gas Chromatography Mass Spectrometry

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Guo-wei Zhou ◽  
Yong-mei Li ◽  
Chun-ni Liu ◽  
Hong-min Ren ◽  
Hai-ying Li
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Mixed Solvents ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
External Standard Method ◽  
Relative Standard ◽  
Schizonepeta Tenuifolia

A simple, fast, and reliable method was established for simultaneous determination of 43 pesticides in Schizonepeta tenuifolia. The samples were prepared using solid-phase extraction (SPE) method. Pesticides were extracted from Schizonepeta tenuifolia using acetonitrile, cleaned with Pesticarb/NH2, and eluted by mixed solvents of acetonitrile and toluene (3 : 1, v/v). Selected pesticides were identified using DB-35MS capillary column and detected by gas chromatography mass spectrometry. Samples were quantified by external standard method. Recoveries for the majority of pesticides at spike levels of 0.2, 0.5, and 1 mg kg−1 ranged between 70 and 120% (except for Chlorothalonil, Thiamethoxam, and Dicofol), and the relative standard deviations (RSDs n = 6) were 1.32%–13.91%. Limits of detection (LODs) were 0.0011–0.0135 mg kg−1, whereas limits of quantification (LOQs) were 0.0038–0.0451 mg kg−1. The satisfactory accuracy and precision, in combination with a good separation and few interferences, have demonstrated the strong potential of this technique for its application in Schizonepeta tenuifolia analysis.

Gas Chromatographic Determinatiion of Monoethylene Glycol and Diethylene Glycol in Chocolate Packaged in Regenerated Cellulose Film

1988 ◽  
Vol 71 (3) ◽  
pp. 499-502
Author(s):  
Laurence Castle ◽  
Helen R Cloke ◽  
James R Startin ◽  
John Gilbert
Keyword(s):  
Gas Chromatography ◽  
Diethylene Glycol ◽  
Internal Standard ◽  
Hot Water ◽  
Gas Chromatography Mass Spectrometry ◽  
Regenerated Cellulose ◽  
Regenerated Cellulose Film ◽  
Relative Standard ◽  
Monoethylene Glycol

Abstract A method for the quantitative determination of monoethylene glycol (MEG) and diethylene glycol (DEG) in chocolate is described. The procedure involves dissolving the chocolate in hot water, defatting with hexane, removing sugars by precipitation, and analyzing as trimethylsilyl (TMS) ether derivatives by capillary gas chromatography. The use of butan-l,4-dioI as an internal standard corrects for recovery, which is between 50 and 60%, to give a relative standard deviation of 10 -11 % for the determination of both glycols at the level of 50 mg/kg. The presence of MEG and DEG in chocolate is confirmed by full scanning gas chromatography/mass spectrometry of the TMS derivatives

Quantitation of Cyfluthrin in Liquid and Solid Formulations by Reversed-Phase Liquid Chromatography: Collaborative Study

1995 ◽  
Vol 78 (6) ◽  
pp. 1335-1338 ◽  
Author(s):  
Donald N Harbin
Keyword(s):  
Collaborative Study ◽  
Internal Standard ◽  
Reversed Phase ◽  
Matched Pair ◽  
Reversed Phase Liquid Chromatography ◽  
Pesticide Formulations ◽  
Relative Standard ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A liquid chromatographic (LC) method has been developed for quantitation of cyfluthrin (Baythroid®, Tempo®) in liquid and solid formulations. Cyfluthrin is a synthetic pyrethroid insecticide. Samples are dissolved in acetonitrile and analyzed by reversedphase LC with decanophenone as an internal standard. Seventeen laboratories from 7 countries participated in a collaborative study of the method. Each collaborator was provided with reference standard, internal standard, and matched pair samples of Tempo 20 wettable powder, Tempo 2 emulsifiable concentrate, and Tempo 2 flowable liquid formulations. Collaborators were instructed to use peak area measurements for quantitation. Relative standard deviations for reproducibility (RSDR) were 0.78,0.98, and 2.32, respectively. The LC method for determination of cyfluthrin in pesticide formulations has been adopted first action by AOAC INTERNATIONAL.

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