scholarly journals Distribution of Pesticides in Different Commonly Grown Vegetables of Cameron Highlands, Pahang, Malaysia

2021 ◽  
Vol 50 (10) ◽  
pp. 2937-2944
Author(s):  
Nusrat Munawar ◽  
Yang Farina Yang Farina ◽  
Mohammad Yaqoob ◽  
Abdul Nabi Abdul Nabi ◽  
Syed Munawar Shah Syed Munawar Shah
Keyword(s):  
Gas Chromatography ◽  
Limit Of Detection ◽  
Organophosphorus Pesticides ◽  
Pca Analysis ◽  
Wet Season ◽  
Vegetable Samples ◽  
Detection Frequency ◽  
Relative Standard ◽  
Pyrethroid Pesticides ◽  
Cameron Highlands

Gas chromatography-electron capture detector (GC-ECD) is used to extract and analyse pesticides in vegetable samples collected from Cameron Highlands, Pahang, Malaysia. The limit of detection (LOD) for all pesticides was in the range of 0.03 to 4.5 ng g-1. Recoveries in cabbage, lettuce, and celery ranged from 61.8%-121%, 60-128% and 60%-114%, respectively. The relative standard deviation (RSD) ranged 0.2-15% in cabbage, 0.5-18% in lettuce and 3-19.8% in celery. Organochlorine pesticides (OCPs) concentrations increased down the valley with dichlorodiphenyldichloroethylene (DDE) having the highest concentration at 233 µg kg-1. Organophosphorus pesticides (OPPs) were found to be dispersed throughout the valley, with the highest concentration of parathion ethyl (133 µg kg-1) whereas the pyrethroid pesticides (PYRs) concentrations were comparatively less. The detection frequency in the wet season was highest (5 < - < 100 µg kg-1) for most pesticides. However, in the dry season the pesticides concentrations were higher, at < 5 µg kg-1. PCA analysis indicated that farmers were using a mixture of pesticides.

scholarly journals Determination of Organophosphorus Pesticide Residues in Winter Bamboo Shoots by Homogenate Extraction Coupled with Gas Chromatography-Flame Photometric Detector

2020 ◽  
pp. 7-12
Author(s):  
Zhu Yu-Xin ◽  
Xu Liu-Yue ◽  
Feng Qi ◽  
Zhu Miao-Qin
Keyword(s):  
Gas Chromatography ◽  
Pesticide Residues ◽  
Limit Of Detection ◽  
Organophosphorus Pesticides ◽  
Flame Photometric Detector ◽  
Photometric Detector ◽  
Bamboo Shoots ◽  
Homogenate Extraction ◽  
Relative Standard

Excessive use of organophosphorus pesticides (OPPs) in fruits and vegetables may affect human health. In this paper, a simple, rapid and effective method for the determination of five OPPs in winter bamboo shoots by gas chromatography-flame photometric detector (GC-FPD) was developed. Three extractants and three extraction methods were examined respectively. The results showed that the recovery rate was higher when the samples were extracted by acetonitrile and treated with homogenate extraction method. Under the optimized conditions, recoveries ranged from 82.12% to 91.48% with the relative standard deviation (RSD) of 1.51-4.20% and the limit of detection (LOD) of 0.005-0.02 μg/mL. Results showed that using acetonitrile as extractants and homogenate extraction in sample preparation is an effective method in determination of pesticide residues in winter bamboo shoots.

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 &lt;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.

Detection of pesticide residues in vegetables sold in Changchun City，China

2020 ◽  
Author(s):  
Mengmeng Jiang ◽  
Haicheng Gao ◽  
Xinxin Liu ◽  
Yu Wang ◽  
Jiaqi Lan ◽  
...  
Keyword(s):  
Pesticide Residues ◽  
Detection Rate ◽  
Organophosphorus Pesticides ◽  
Pollution Level ◽  
Potential Health ◽  
Chemical Structures ◽  
Compound Pollution ◽  
Fresh Vegetables ◽  
Relative Standard ◽  
Pyrethroid Pesticides

In this essay we investigate mainly 18 pesticide residues with different chemical structures in fresh vegetables, including organochlorine pesticides, organophosphorus pesticides, carbamate pesticides and pyrethroid pesticides. At the same time, it is estimated that the potential health risks for residents. A total of 313 samples were collected from 12 kinds of vegetables from Changchun, the capital of Jilin Province,China. 18 pesticide residues in 313 samples were analyzed by Gas chromatography and mass spectrometry (GC-MS) . Testing linearity was favorable in the range of 0.01 - 1.00μg/mL, R 2 ≥0.99, and the recovery rate of pesticides was 62% - 110%, the relative standard deviation &lt; 5%, the detection limit of the pesticide is 0.0001 - 0.0167 mg / kg, the limit of quantification is 0.0002 - 0.0556 mg / kg. Overall, the detection rate of pesticides was 28.43%, and the detection rate and over-standard rate of celery were the highest, while the pesticide detection rate of potatoes was the lowest, and the pesticide exceeding rate of cucumber was the lowest. Three pesticides tested were not detected in the 18 pesticides including heptachlor, chlorpyrifos and permethrin. Among the 15 pesticides detected, the maximum risk factor of 7 pesticides is greater than 1 such as carbofuran, omethoate, phorate, dicofol, dimethoate, chlorpyrifos and dichlorvos, which may cause potential harm to human health. In contrast others will be safe. It could not have significant perniciousness for people from the perspective of single pollution level,, but it is not ignored there are multiple pesticide residue compound pollution to endanger persons' health.

scholarly journals Determination of Gliclazide in Pharmaceutical Preparations by Capillary Gas Chromatography with Cool On-Column Injection and Elimination of the Matrix Effect

2001 ◽  
Vol 84 (6) ◽  
pp. 1695-1702 ◽  
Author(s):  
Jan Krzek ◽  
Janusz Czekaj ◽  
Maria Moniczewska ◽  
Włodzimierz Rzeszutko
Keyword(s):  
Gas Chromatography ◽  
Capillary Gas Chromatography ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Pharmaceutical Preparations ◽  
Fused Silica ◽  
Uv Spectrophotometry ◽  
Relative Standard ◽  
Wide Range ◽  
The Matrix

Abstract Conditions were established for the identification and quantitation of gliclazide in pharmaceutical preparations by capillary gas chromatography with flame ionization detection and cool on-column injection. Gliclazide was extracted with methanol and, after filtration, assayed on a (25 m × 0.25 mm id, 0.2 μm film thickness) CP-WAX 58 (FFAP)–CB WCOT fused silica column. Because the available preparations were of various origins and, therefore, could differ in auxiliary substances and their qualitative parameters, the influence of the matrix constituents on the analytical results was taken into account. Good separation conditions were established for the developed method. The retention time of gliclazide is about 36 min and differs from the retention times of the internal standard (approximately 29 min) and additional peaks present in chromatograms (20–26 min), which were assigned to matrix constituents. The recoveries of gliclozide were high and reached 96.5%. The developed method is characterized by selectivity and precision (relative standard deviation 0.38–1.26%), a wide range of linearity (0.1–10.0 mg/mL), and a limit of detection of 30 ng. In addition, the results of chromatographic analyses calculated in 3 ways were compared with those obtained by UV spectrophotometry. The suggested technique of cool on-column injection, in contrast with split-splitless injection (used in preliminary investigations), reduces to a minimum the possibility of thermal decomposition of gliclazide.

scholarly journals Multiresidue Determination of Pesticides in Honey by Matrix Solid-Phase Dispersion and Gas Chromatography with Electron-Capture Detection

2001 ◽  
Vol 84 (4) ◽  
pp. 1165-1171 ◽  
Author(s):  
Beatriz Albero ◽  
Consuelo Sánchez-Brunete ◽  
José L Tadeo
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Solid Phase ◽  
Organophosphorus Compounds ◽  
Organophosphorus Pesticides ◽  
Electron Capture Detection ◽  
Matrix Solid Phase Dispersion ◽  
Phase Dispersion ◽  
Relative Standard

Abstract A multiresidue method was developed for the determination of 15 pesticides (organochlorines, organophosphorus compounds, pyrethroids, and other acaricides) in various commercial honeys (eucalyptus, lavender, orange, rosemary, and multifloral). The analytical procedure is based on the matrix solid-phase dispersion of honey in a mixture of Florisil and anhydrous sodium sulfate; the mixture is placed in small plastic columns and extracted with hexane–ethyl acetate (90 + 10, v/v). The pesticide residues are determined by capillary gas chromatography with electron-capture detection. Recoveries with the method at concentrations between 0.15 and 1.5 μg/g ranged from 80 to 113%, and relative standard deviations were &lt;10% for all the pesticides studied. The pesticide detection limits were within the range 0.5–5 mg/kg for organochlorines, around 3 μg/kg for the chlorinated organophosphorus pesticides studied, near 15 μg/kg for fluvalinate, and about 3 μg/kg for the other pyrethroids.

Determination Method of Organophosphorus Pesticide Residues in Fishs by GPC-GC-PFPD

2011 ◽  
Vol 138-139 ◽  
pp. 1002-1006
Author(s):  
Bin Li ◽  
Fan Gang Zeng ◽  
Wei Fang Ma ◽  
Qi Chun Dong ◽  
Hai Tao Fan ◽  
...  
Keyword(s):  
Pesticide Residues ◽  
Limit Of Detection ◽  
Organophosphorus Pesticides ◽  
Organophosphorus Pesticide ◽  
Gel Permeation Chromatography ◽  
Determination Method ◽  
Average Recovery ◽  
Relative Standard ◽  
Gel Permeation ◽  
Good Repeatability

The 10 organophosphorus pesticides in fish can be rapidly extracted and separated by gel permeation chromatography, and the lipin and organophosphorus pesticides of fish can be seperated. The interfering matters can be well eliminated in this condition, and analysis is more rapid than other methods. The residues of 10 organophosphorus pesticides at same time can be identified and quantified simultaneously by GC-PFPD. This method is simple, rapid, and the average recovery ratios were 71.7%-80.9%.Good repeatability was obtained in all the cases with relative standard deviations (RSDs) lower 11%, and limit of detection was0.0003-0.004 mg·kg-1.

Lactic Acid Determination in Human Plasma Using Ultrasound-Assisted Emulsification Microextraction Followed by Gas Chromatography

2016 ◽  
Vol 69 (4) ◽  
pp. 451 ◽  
Author(s):  
Parvin Shahdousti ◽  
Rezvan Shojaee ◽  
Mohammad Aghamohammadi ◽  
Behrang Harooni
Keyword(s):  
Gas Chromatography ◽  
Lactic Acid ◽  
Human Plasma ◽  
Limit Of Detection ◽  
Aqueous Sample ◽  
Extraction Solvent ◽  
Relative Standard ◽  
Ultrasound Assisted ◽  
Emulsification Microextraction

A rapid, sensitive, and accurate analytical method was developed for determination of lactic acid (LA) in human plasma to monitor lactic acidosis. This method was based on an ultrasound-assisted emulsification microextraction (USAEME) method followed by gas chromatography with flame ionization detection (GC–FID). Derivatization of LA was carried out by a low density alcoholic solvent which performs both as an extraction solvent and derivatization agent, simultaneously. In this procedure, 100 μL of binary mixtures of pentan-1-ol with toluene (70 : 30, v/v %) was slowly injected into a 10 mL acidified aqueous sample of LA placed into an ultrasonic water bath. The resulting emulsion was centrifuged and after derivatization, 2 μL of organic phase was analysed by GC–FID. The effective variables were evaluated to optimize the efficiency of USAEME. Under the optimum conditions, good linearity in the range of 0.06–7.77 mmol L–1 was obtained with a correlation coefficient (R2) of 0.991 and a limit of detection (LOD) of 0.04 mmol L–1 for water samples. The inter-day and intra-day repeatability of the proposed method in human plasma were evaluated in terms of the relative standard deviation (RSD %) and were found to be <10 %. The results revealed that the USAEME–GC–FID method can be applied successfully for determination of LA in human plasma samples with satisfactory accuracy and precision.

scholarly journals Analytical Study of Comprehensive and Targeted Multidimensional Gas Chromatography Incorporating Modulated Cryogenic Trapping

2001 ◽  
Vol 84 (2) ◽  
pp. 323-336 ◽  
Author(s):  
Thy T Truong ◽  
Philip J Marriott ◽  
Nichola A Porter
Keyword(s):  
Gas Chromatography ◽  
Normal Mode ◽  
Analytical Study ◽  
Limit Of Detection ◽  
Internal Standard ◽  
Complete Separation ◽  
Pollution Monitoring ◽  
Detection Sensitivity ◽  
Constant Frequency ◽  
Relative Standard

Abstract This paper reports the results of an analytical study comparing capillary gas chromatography (GC) operated in the normal mode with 2 new GC techniques, comprehensive GC (GC × GC) and targeted (or selective) multidimensional GC, which use a longitudinally modulated cryogenic system (LMCS), recently developed in our laboratory. A high-temperature application of derivatized sterols, of interest in fecal pollution monitoring, was chosen for this work. A directly connected coupled-column ensemble was used, comprising a nonpolar column and a moderately polar column. With LMCS, effluent from the first column is zone-compressed in a cryogenic trap and then pulsed to a short second column, producing narrower peaks with sharp, tall peak responses at the detector. The modulator is operated at a constant frequency, e.g., 0.25 s−1, to produce the GC × GC result, or is moved in a predefined manner so that whole peaks are selectively trapped and subsequently pulsed through to the second column in the targeted mode. Standard solutions containing a mixture of 7 sterols and 5-α-cholestane internal standard were used. Detection sensitivity is increased by a factor of ≥25 with the use of LMCS. The estimated limit of detection was about 0.1 μg/mL when normal GC with flame ionization detection (GC/FID) and a 1.0 μL splitless injection volume were used, compared with 0.02 and 0.004 μg/mL for the LMCS operated in GC × GC and selective modes, respectively. Calibration curves for GC/FID were linear over the 0.1–2.0 μg/mL range tested. Reproducibilities for the GC × GC and normal GC modes were comparable; generally, relative standard deviations (RSD) were on the order of 3–4%, based on raw peak responses. Improved reproducibility was found for selective LMCS operation, at an RSD of around 2%; with internal standardization, better results were achieved. The coupled-column arrangement allowed complete separation of sterol peaks from overlapping impurity peaks in a number of instances with LMCS modes, and its use should improve data quality over that of normal GC operation, in which the overlapping peaks interfere with measurement of peak response in the normal mode.

scholarly journals Gas Chromatography-Tandem Mass Spectrometry Method for Selective Detection of 2-Nitropropane in Mainstream Cigarette Smoke

2019 ◽  
Vol 28 (7) ◽  
pp. 300-309
Author(s):  
Gala M. Chapman ◽  
Juliana Giraldo Junco ◽  
Roberto Bravo Cardenas ◽  
Clifford H. Watson ◽  
Liza Valentín-Blasini
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Tandem Mass Spectrometry ◽  
Cigarette Smoke ◽  
Limit Of Detection ◽  
Tandem Mass ◽  
Chromatography Tandem Mass Spectrometry ◽  
Relative Standard ◽  
Standard Deviations ◽  
Mainstream Cigarette Smoke

SummaryAlthough 2-nitropropane is a potentially harmful compound present in cigarette smoke, there are few fully-validated, modern methods to quantitate it in mainstream cigarette smoke. We developed an isotope dilution gas chromatography-tandem mass spectrometry (ID-GC-MS/MS) method for the detection of 2-nitropropane in mainstream cigarette smoke. The vapor fraction of mainstream cigarette smoke was collected in inert polyvinyl fluoride gas sampling bags and extracted with hexanes containing isotopically labeled internal standard, then purified and concentrated via solid-phase extraction using a normal phase silica adsorbent and a 100% dichloromethane eluant. This method is sensitive enough to measure vapor phase 2-nitro-propane concentrations in the nanogram range, with a 19 ng per cigarette method limit of detection. Product variability estimated from the analysis of 15 cigarette products yielded relative standard deviations ranging from 5.4% to 15.7%, and estimates of precision from two quality control products yielded relative standard deviations of 9.49% and 14.9%. Under the Health Canada Intense smoking regimen, 2-nitropropane in machine-generated mainstream smoke from 15 cigarette products ranged from 98.3 to 363 ng per cigarette.

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