Monitoring and method validation of organophosphorus/organochlorine pesticide residues in vegetables and fruits by gas chromatography.

In this study, an analytical method was developed and validated for the assessment of pesticide residues in commonly consumed vegetables and fruits. Fresh samples of apple, green peas, tomatoes, and cucumbers were processed and subjected to analysis using a modified QuEChERS (quick, easy, cheap, effective, rugged, safe) extraction technique. Subsequently, quantification of pesticide residues was conducted utilizing gas chromatography (GC)-electron capture detector. Extraction and cleanup parameters were meticulously optimized, resulting in a modification of the original QuEChERS method. This modification aimed to reduce solvent consumption, making the study more environmentally friendly. The developed method was validated in terms of selectivity, specificity, linearity, precision, and accuracy by following the SANTE guidelines. Calibration curves showed good linearity (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day experiments with an acceptable relative standard deviation (<20.0%). Recovery was assessed at the limit of quantification level and was observed to fall within the range of 70%-120%, with relative standard deviations below 5.45%. The validated method presented here can be applied to analyze pesticide residues in various other vegetables, fruits, and cereals. It is essential for ongoing monitoring of pesticide residues to ensure public safety.

Method validation and residue determination of mineral oil Arbofine in apple and soil using gas chromatography-flame ionisation detection under temperate conditions of Kashmir, India.

This innovative study was carried out to determine the presence of the mineral oil Arbofine in apple and soil at four locations. Arbofine kills the vast majority of dormant insects and mites (mite and asphid eggs, scales and psyllids) on fruit trees (cherry, apple, plum and peach) and thus reduces the plant diseases in summer. In this study, the mineral oil was sprayed at recommended doses of 2.0 and 0.75%, and the doses were doubled to 4.0 and 1.5% in dormant and summer seasons, respectively. The soil samples were taken for observation during the dormant season, whereas both soil and apple samples were taken during the summer season after treatment for 0, 1, 3 and 5 days. The recovery study of all the 11 paraffinic constituents (n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-undecane, n-dodecane, n-tridecane, n-tetradecane and n-pentadecane) in soil and apple samples which constitutes 60% of mineral oil in soil and apple was carried out at the fortification level of 1.0 µg/ml, which was found to be between 72.1% and 99.0%. No residue of all the 11 paraffinic compounds of Arbofine mineral oil was detected in soil and apple samples at day 0 after the recommended doses, and the recommended doses were doubled in both seasons at four locations. Therefore, mineral oil can be used on apples without any risk.

Dissipation kinetics, residue determination and consumer risk assessment of acephate on green pea by gas chromatography-electron capture detector.

The present study on "acephate persistence on green pea" was conducted in SKUAST-Kashmir. The study aimed to determine the persistence, dissipation kinetics and waiting period of acephate on green pea. Acephate was sprayed at 75% soluble powder (SP) at 560 g a.i.ha-1 at the fruiting stage followed by another application at a 10 day interval. A rapid and accurate method (quick, easy, cheap, effective, rugged and safe, QuEChERS) was used for extraction and the residue was determined by gas chromatography-electron capture detection on a CPSIL-8CB capillary column (0.25um film thickness, 0.25 mm i.d, 30 m length). At the fortification levels of 0.05, 0.1 and 0.5 mg kg-1 , the percentage recovery of acephate on green pea was found in the range of 71-107%. The initial deposit of green pea was estimated to be 0.37 mg kg-1 . At the indicated dose, the residue of acephate on green pea dissipated below the limit of quantification of 0.05 mg kg-1 after 10 days. Acephate degradation was quick in green pea, with a half-life of 4.07 days. For safe eating of green peas, a 10 day waiting period is recommended. The gas chromatography-electron capture detection technique was validated by following the SANTE standards.

Development and validation of gas chromatography with electron capture detection method using QuEChERS for pesticide residue determination in cucumber.

A modified quick, easy, cheap, efficient, rugged, and safe (QuEChERS) method coupled to gas chromatography with electron capture detection was developed for the simultaneous determination of selected electronegative pesticides, namely, chlorpyrifos-methyl (1), chlorpyrifos (2), quinolphos (3), profenofos (4), myclobutanil (5), ethion (6), fenpropathrin (7), and cypermethrin (8), in vegetables with high water content. The selected compounds and some of their metabolites have even been found in human body fluids. In addition, some of them are known or suspected carcinogens according to the World Health Organization. Extraction and cleanup parameters were optimized; thus, the original QuEChERS method was modified to minimize solvent usage by making the study eco-friendly. The developed method was validated for selectivity, specificity, linearity, precision, and accuracy using SANTE guidelines. Calibration curves showed good linearity (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day experiments with an acceptable range of less than 20.0% of relative standard deviation. Recovery was evaluated at limit of quantification and was found to be in the range of 70-120%, with relative standard deviations lower than 4.21%. The proposed method is applicable for detection and monitoring of selected pesticides in one run not only in fruits and vegetables with high water content but also in samples containing large quantities of pigments/dyes.

Simultaneous quantification of losartan potassium and its active metabolite, EXP3174, in rabbit plasma by validated HPLC-PDA.

Herein, we report a novel, accurate and cost-effective validated analytical method for the quantification of losartan potassium and its active metabolite, EXP 3174, in rabbit plasma by reversed-phase high-performance liquid chromatography. Valsartan was used as an internal standard. The method was validated as per International Conference on Harmonization guidelines. The analytes were extracted in rabbit plasma using liquid-liquid extraction technique and analyzed at 247 nm after separation through a reverse-phase C18 column. The isocratic mobile phase used is a mixture of acetonitrile, water and glacial acetic acid in the ratio of 60:40:1 v/v/v maintained at pH 3.4. All calibration curves showed a good linear relationship (r > 0.995) within the test range. Precision was evaluated by intra- and interday tests with RSDs <1.91% and accuracy showed validated recoveries of 86.20-101.11%. Based on our results, the developed method features good quantification parameters and can serve as an effective quality control method for the standardization of drugs.

Risk assessment, development and validation of a GC-ECD-based method for the quantification of cypermethrin from green pea.

The present work describes the persistence, dissipation behaviour, half-life, risk assessment and novel gas chromatography method for the residue estimation of cypermethrin in green pea by spraying cypermethrin 10EC at 50 g a.i. ha-1 at fruiting stage followed by another application at a 10 day interval. The sample extraction and cleanup was followed bya modified quick, easy, cheap, effective, rugged, and safe method, and the residues of cypermethrin were determined using a validated gas chromatography method. The initial deposits were found to be 1.21 mg kg-1 following the application of insecticide at 50 g a.i. ha-1 . Cypermethrin residues declined to below the detection limit of 0.05 mg kg-1 after 15 days at the recommended dosage. The half-life of cypermethrin was 2.66 days at 50 g a.i. ha-1 . For risk assessment studies, the waiting period of 15 days is recommended as safe for consumption for the insecticide. The GC-ECD method was validated according to the SANTE guidelines by various analytical parameters including linearity, accuracy, detection and quantification limits. The developed method is simple, selective and repeatable, and can be used for the standardization of pesticides on fruits and vegetables.

Dissipation and gas chromatographic method for the determination of profenofos residues in/on green pea and cucumber.

Herein we report a novel, accurate and cost-effective gas chromatography method for the determination of average deposits of profenofos on green pea and cucumber following good agricultural practices. Additionally the risk assessment, dissipation and waiting period for profenofos were determined. The average initial deposits (2 h after spraying) of profenofos in/on green pea and cucumber were 3.41 and 3.62 mg kg-1 respectively following two applications at a 10 day interval of profenofos 50EC formulation. Profenofos residues on both of the substrates were below the detection limit of 0.05 mg kg-1 after 20 days at the recommended dosage. For risk assessment studies, the 20th day will be safe for consumers for consumption of green peas. The gas chromatography method was validated according to the SANTE guidelines using the various analytical parameters: linearity, accuracy, detection and quantification limits. The developed method is simple, selective and repeatable and can be extended for profenofos-based standardization of pesticide formulations for green pea/cucumber and their use as pesticides.

Method validation and simultaneous quantification of eight organochlorines/organophosphates in apple by gas chromatography.

BACKGROUND: The increasing and extensive use of pesticides worldwide has resulted in a significant loss of non-target populations particularly humans by direct or indirect exposures. Also, various methods have been used for the estimation of pesticide residues in fruits and vegetables from recent past which are either tedious, time consuming or expensive. Therefore, the present study was performed to determine the pesticide residues from apple by simple and novel validated gas chromatography. RESULTS: A novel, accurate, ecofriendly and cost-effective gas chromatography method was developed for simultaneous quantification of eight pesticides, namely chlorpyrifos-methyl (1), chlorpyrifos (2), quinolphos (3), profenofos (4), myclobutnil (5), ethion (6), fenpropathrin (7) and cypermethrin (8). The developed method was validated as per the SANTE guidelines. All calibration curves showed a good linear relationship (r > 0.99) within the test range. Precision was evaluated by intra- and inter-day tests with relative standard deviations (RSDs) < 2.0%, recovery in between 70% and 120% with RSDs < 2.00%. CONCLUSION: The results demonstrate that the concentration of pesticides 1 to 8 were found below the detectable limit. Method validation parameters like linearity, precision, accuracy, specificity, robustness, detection and quantification limits were found within the acceptable range. The proposed method makes it possible to determine simultaneously pesticides 1-8 in one run which can be extended for residue-based standardization of pesticides from apple and other fruits and vegetables. © 2019 Society of Chemical Industry.

Risk assessment, dissipation behavior and persistence of quinalphos in/on green pea by gas chromatography with electron capture detector.

Chemical investigation was carried out to examine the risk assessment, dissipation behavior, persistence, and half-life period of quinalphos in/on green pea fruit by spraying quinalphos at fruiting stage followed by another application after 10-day interval. The samples were extracted by using the quick, easy, cheap, effective, rugged, and safe method, and the residues of quinalphos were analyzed by gas chromatography with electron capture detector. Herein, we report a novel, accurate, and cost-effective gas chromatography method for the determination of average deposits of quinalphos in/on green pea. The initial deposits and half-life of quinalphos were found to be 1.20 mg/kg and 2.77 days, respectively, following the application of insecticide. Residues of quinalphos reached below detection limit of 0.05 mg/kg after 10 days at recommended dosage. For risk assessment studies, the tenth day will be safe for consumers for consumption of green pea. The developed method is simple, selective, and repeatable, and it can be extended for quinalphos-based standardization of herbal formulations containing green pea and its use in pesticide industries.

Quantification, dissipation behavior and risk assessment of ethion in green pea by gas chromatography-electron capture detector.

Residue investigation was carried out to scrutinize the persistence, dissipation behavior, half-life, and risk assessment of ethion on green pea fruit by spraying ethion at the fruiting stage followed by another application at 10 day intervals. The samples were extracted by using a quick, easy, low-cost, effective, rugged, and safe method, and the residues of ethion were analyzed by gas chromatography with electron capture detection. Here we report a novel, accurate, and cost-effective gas chromatography method for the determination of average deposits of ethion on green pea. The initial deposits were found to be 4.65 mg/kg following the application of insecticide. Residues of ethion reached below the detection limit of 0.10 mg/kg after 25 days at recommended dosage. The half-life of ethion was found to be 4.62 days. For risk assessment studies, the 25th day will be safe for consumers for the consumption of green peas. The developed method is simple, sensitive, selective, and repeatable and can be extended for ethion-based standardization of herbal formulations containing green pea and its use in pesticide industries.

Health Risk Assessment of Pesticide Residues in Drinking Water of Upper Jhelum Region in Kashmir Valley-India by GC-MS/MS.

Globally growing demand for agricultural and farm foods has more or less become dependent on chemical pesticides to maintain the supply chain, which undoubtedly boosts agricultural production. However, pesticides not only impact the target pests but cause hazard to human health. Pesticides are ubiquitous and can be found in almost every component of the environment. They can therefore impair human and biota health when present over the threshold level. The present study assessed the concentration of commonly used pesticides for agricultural purposes but get mixed in different sources of water, as such fifteen sampling sites along the upper Jhelum basin of Kashmir valley were chosen. For the analysis, 60 water samples were obtained from different water sources. Gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) was used to determine pesticide residues in water samples. Pesticide residues from 10 of the 26 commonly used pesticides were detected in water samples. Difenoconazole had the highest concentration among the pesticides detected, with a mean concentration of 0.412 ± 0.424 µg/L ranging from 0.0 µg/L to 0.8196 µg/L. The target hazards quotient (THQ) was used to quantify the possible noncarcinogenic health risks associated with drinking pesticide-contaminated water. Only chlorpyrifos and quinalphos were detected >1 in RWS3 (1.6571), RWS4 (1.0285), RWS14 (1.2571), and RWS15 (1.2000) sample sites, implying that the drinking water poses a health risk to humans. Hence, pesticide hazards should be mitigated and rigorous monitoring is needed to reduce pesticide residues in drinking water.