scholarly journals Determination of Phytosterols in vegetable oils by GC-MS method

2020 ◽  
Vol 3 (4) ◽  
pp. 36-42
Author(s):  
Hien Dang Thu ◽  
Ngoc Anh Mai Thi ◽  
Hong Ngoc Nguyen Thi ◽  
◽  
◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Vegetable Oils ◽  
Limit Of Detection ◽  
Alkaline Media ◽  
Gas Chromatography Mass Spectrometry ◽  
Limit Of Quantification ◽  
Chromatography Mass Spectrometry ◽  
Trimethylsilyl Ethers

In this study, a method for determination of six phytosterols by gas chromatography-mass spectrometry with derivatization in vegetable oils was validated. The samples were hydrolyzed in an alkaline media at 70°C for 60 min. Then, the samples were performed liquid-liquid extraction with toluene. The phytosterols are derivatized to trimethylsilyl ethers and then analyzed by gas chromatography-mass spectrometry. The limit of detection and limit of quantification was 5 and 15 mg/kg, respectively. Recoveries of six phytosterols were between 93.5% and 101%.

Simultaneous Determination of Alachlor, Metolachlor, Atrazine, and Simazine in Water and Soil by Isotope Dilution Gas Chromatography/Mass Spectrometry

1989 ◽  
Vol 72 (2) ◽  
pp. 349-354 ◽  
Author(s):  
Lee Q Huang
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Isotope Dilution ◽  
Limit Of Detection ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Chromatography Mass Spectrometry

Abstract A multiresidue method was developed for the simultaneous determination of low parts per billion (ppb) concentrations of the herbicides alachlor, metolachlor, atrazine, and simazine in water and soil using isotope dilution gas chromatography/mass spectrometry (GC/MS). Known amounts of 15N,13C-alachlor and 2H5-atrazine were added to each sample as internal standards. The samples were then prepared by a solid phase extraction with no further cleanup. A high resolution GC/low resolution MS system with data acquisition in selected ion monitoring mode was used to quantitate herbicides in the extract. The limit of detection was 0.05 ppb for water and 0.5 ppb for soil. Accuracy greater than 80% and precision better than 4% was demonstrated with spiked samples.

scholarly journals Extraction-Free, Direct Determination of Caffeine in Microliter Volumes of Beverages by Thermal Desorption-Gas Chromatography Mass Spectrometry

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Xianglu Peng ◽  
Melanie Brown ◽  
Paul Bowdler ◽  
Kevin C. Honeychurch
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Thermal Desorption ◽  
Limit Of Detection ◽  
Direct Determination ◽  
Energy Drink ◽  
Gas Chromatography Mass Spectrometry ◽  
Pyrolysis Gas ◽  
Chromatography Mass Spectrometry

An extraction-free method requiring microliter (μL) volumes has been developed for the determination of caffeine in beverages. Using a pyrolysis-gas chromatography mass spectrometry system, the conditions required for the direct thermal desorption-gas chromatography mass spectrometry (TD-GC/MS) determination of caffeine were optimised. A 5 μL aliquot was introduced to the thermal desorption unit, dried, and thermally desorbed to the GC/MS. The response was linear over the range 10 to 500 μg/mL (R2 = 0.996). The theoretical limit of detection (3 σ) was 0.456 μg/mL. No interferences were recorded from endogenous beverage components or from commonly occurring drugs, such as nicotine, ibuprofen, and paracetamol. Replicate caffeine determinations on fortified latte style white coffee and Pepsi Max® gave mean recoveries of 93.4% (%CV = 4.1%) and 95.0% (%CV = 0.98%), respectively. Good agreement was also obtained with the stated values of caffeine for an energy drink and for Coca-Cola®. These data suggest that the method holds promise for the determination of caffeine in such samples.

Simultaneous determination of tocopherols and tocotrienols in vegetable oils by GC-MS

2016 ◽  
Vol 8 (40) ◽  
pp. 7341-7346 ◽  
Author(s):  
Rui Zhang ◽  
Weijian Shen ◽  
Xueyuan Wei ◽  
Feifang Zhang ◽  
Chongyu Shen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Simultaneous Determination ◽  
Vegetable Oils ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry

A simple and rapid gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the simultaneous determination of α-, β-, γ- and δ-tocopherols and α-, β-, γ- and δ-tocotrienols in vegetable oils.

scholarly journals A simplified approach for determination of urinary ethyl glucuronide by gas chromatography–mass spectrometry

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shayani Ghosh ◽  
Raka Jain ◽  
Satpal Singh ◽  
Ravindra Rao ◽  
Ashwani Kumar Mishra ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Human Urine ◽  
Impact Ionization ◽  
Limit Of Detection ◽  
Extraction Procedure ◽  
Ethyl Glucuronide ◽  
Gas Chromatography Mass Spectrometry ◽  
Limit Of Quantification ◽  
Chromatography Mass Spectrometry

AbstractUrinary ethyl glucuronide (EtG), an alcohol biomarker, plays an essential role in monitoring alcohol abstinence and relapse during treatment for alcohol dependence. Detection of this biomarker has become a routine in many clinical and forensic laboratories over the last few years. Most previously published methods commonly use hyphenated chromatographic techniques along with extensive extraction procedure before analysis. This work aimed to develop and validate an electron impact ionization mode gas chromatography–mass spectrometry method to measure ethyl glucuronide levels in human urine. For its determination, urine samples were dried under a gentle stream of nitrogen, derivatized with N,O-bis(trimethylsilyl) trifluoroacetamide, incubated, and injected into the instrument. The analysis was performed using single quadrupole gas chromatography–mass spectrometry (GC-MS) technology and validation was performed according to the guidelines of the German Society of Toxicology and Forensic Chemistry (GTFCh). The linearity of urinary EtG was obtained in the range of 30–5000 ng/ml with a correlation coefficient (r) above 0.999. The extraction recoveries exceeded 80%, and the obtained inter-day and intra-day precisions were below 15%. The achieved limit of detection was 10 ng/ml and limit of quantification achieved was 30 ng/ml. The electron ionization gas chromatography–mass spectrometry technique proves to be a feasible option for determining EtG in human urine when other sophisticated techniques are unapproachable. This method provides a good sensitivity and proves to be cost-effective, robust, and advantageous for both clinical as well as forensic settings.

scholarly journals Single-Laboratory Validation of a Method for the Determination of Furan in Foods by Using Static Headspace Sampling and Gas Chromatography/Mass Spectrometry

2006 ◽  
Vol 89 (5) ◽  
pp. 1417-1424 ◽  
Author(s):  
Patricia J Nyman ◽  
Kim M Morehouse ◽  
Timothy P McNeal ◽  
Gracia A Perfetti ◽  
Gregory W Diachenko
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Apple Juice ◽  
Limit Of Detection ◽  
Peanut Butter ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Relative Standard ◽  
Limit Of Quantitation

Abstract A headspace gas chromatography/mass spectrometry method was developed and validated in-house for the determination of furan in foods. The method of standard additions with d4-furan as the internal standard was used to quantitate furan. The limit of detection and limit of quantitation (LOQ) values ranged from 0.2 and 0.6 ng/g, respectively, in apple juice to 0.9 and 2.9 ng/g, respectively, in peanut butter. Recoveries were obtained at 0.5, 1, 2, and 3 times the LOQ. At 1, 2, and 3 times the LOQ, the recoveries ranged from 89.4 to 108%, and the relative standard deviations ranged from 3.3 to 17.3% for all the matrixes. For apple juice, chicken broth, and infant formula, the averaged coefficients of determination from the linear regression analyses were >0.99 with each food fortified at 0.5, 1, 2, and 3 times the LOQ. The coefficients of determination were >0.99 for green beans and 0.96 for peanut butter with the foods fortified at 1, 2, and 3 times the LOQ. Within-laboratory precision was determined by comparing the amounts of furan found in 18 samples by 2 analysts on different days with different instruments. For most of the foods, the difference between the amounts found by each analyst was <18%. The method was used to conduct a survey of >300 foods. The furan levels found ranged from none detected to 174 ng/g.

scholarly journals Determination of Morphine and Codeine in Human Urine by Gas Chromatography-Mass Spectrometry

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Xiaoqian Zhang ◽  
Mengchun Chen ◽  
Gaozhong Cao ◽  
Guoxin Hu
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Human Urine ◽  
Forensic Identification ◽  
Gas Chromatography Mass Spectrometry ◽  
Linear Calibration ◽  
Selected Ion Monitoring ◽  
Limit Of Quantification ◽  
Chromatography Mass Spectrometry

A sensitive and selective gas chromatography-mass spectrometry (GC-MS) method was developed and validated for the determination of morphine and codeine in human urine. The GC-MS conditions were developed. The analysis was carried out on a HP-1MS column (30 m × 0.25 mm, 0.25 μm) with temperature programming, and Helium was used as the carrier gas with a flow rate of 1.0 mL/min. Selected ion monitoring (SIM) mode was used to quantify morphine and codeine. The derivation solvent, temperature, and time were optimized. A mixed solvent of propionic anhydride and pyridine (5 : 2) was finally used for the derivation at 80°C for 3 min. Linear calibration curves were obtained in the concentration range of 25–2000.0 ng/mL, with a lower limit of quantification of 25 ng/mL. The intra- and interday precision (RSD) values were below 13%, and the accuracy was in the range 87.2–108.5%. This developed method was successfully used for the determination of morphine and codeine in human urine for forensic identification study.

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