scholarly journals Rapid Determination of Ethylene Oxide and 75 VOCs in Ambient Air with Canister Sampling and Associated Growth Issues

Separations ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 35
Author(s):  
Jason Hoisington ◽  
Jason S. Herrington
Keyword(s):  
Ethylene Oxide ◽  
Rapid Determination ◽  
Complex Mixture ◽  
Ambient Air ◽  
Gas Chromatography Mass Spectrometry ◽  
Average Accuracy ◽  
Relative Standard ◽  
Wide Range ◽  
Us Epa

A canister-based sampling method along with preconcentrator-Gas chromatography-Mass Spectrometry (GC-MS) analysis was applied to ethylene oxide (EtO or EO) and 75 other volatile organic compounds (VOCs) in ambient air. Ambient air can contain a large variety of VOCs, and thorough analysis requires non-discriminatory sampling and a chromatographic method capable of resolving a complex mixture. Canister collection of whole air samples allows for the collection of a wide range of volatile compounds, while the simultaneous analysis of ethylene oxide and other VOCs allows for faster throughput than separate methods. The method presented is based on US EPA Method TO-15A and allows for the detection of EtO from 18 to 2500 pptv. The method has an average accuracy of 104% and precision of 13% relative standard deviation (RSD), with an instrument run time of 32 min. In addition, a link between canister cleanliness and ethylene oxide growth is observed, and potential mechanisms and cleaning strategies are addressed.

Gas Chromatography Mass Spectrometry Method of Rapid Determination of Trichloroacetaldehyde in Water Optimization

2013 ◽  
Vol 448-453 ◽  
pp. 359-362
Author(s):  
Mo Jie Sun ◽  
Ling Zhang ◽  
Ruo Kun Jia
Keyword(s):  
Human Error ◽  
Rapid Determination ◽  
Water Source ◽  
Gas Chromatography Mass Spectrometry ◽  
Drinking Water Source ◽  
Purge And Trap ◽  
Relative Standard ◽  
Before And After ◽  
The Difference

Chloral alkali at room temperature Can be quickly converted into chloroform completely, Application of this principle, By Purge and Trap GC/MS method , Determination of the alkali content of chloroform in water before and after the difference, Inverse to get the water content of chloral. NaOH were added to different volumetric flask. It is flask with standard solutions in different concentrations. Aside a certain amount of determination, error is larger. NaOH was injected directly into the injector. This was the method. It completely transformed in Purge and Trap, greatly reduces human error. The linear range is 0.5-20ug/L, the minimum detection limit can reach 0.05ug/L, the relative standard deviation is less than 2.3%, the average recovery was 97.5%. This method is simple and quick,the results are accurate and reliable, which is able to meet the drinking water source in the analytical needs of chloral.

scholarly journals Determination of Pesticides in Composite Dietary Samples by Gas Chromatography/Mass Spectrometry in the Selected Ion Monitoring Mode by Using a Temperature-Programmable Large Volume Injector with Preseparation Column

2001 ◽  
Vol 84 (3) ◽  
pp. 891-900 ◽  
Author(s):  
Laura Rosenblum ◽  
Thomas Hieber ◽  
Jeffrey Morgan
Keyword(s):  
Mass Spectrometry ◽  
Sample Preparation ◽  
Diatomaceous Earth ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Residue Detection ◽  
Relative Standard ◽  
Wide Range ◽  
Mode Method

Abstract Use of a temperature-programmable preseparation column in the gas chromatographic (GC) injection port permits determination of a wide range of semi-volatile pesticides including organochlorines, organophosphates, triazines, and anilines in fatty composite dietary samples while reducing sample preparation time and solvent consumption. Dietary samples are mixed with diatomaceous earth and are Soxhlet-extracted with an azeotropic solution of hexane and acetone. Sample preparation uses liquid–liquid partitioning over diatomaceous earth followed by normal phase chromatography over partially deactivated alumina. The final cleanup step occurs in a preseparation column in the GC injector, which is able to perform splitless transfer of the analytes to the analytical column and purge 99% of the high molecular weight residue. Detection is performed by GC/mass spectrometry (MS) in the selected ion monitoring mode. Method detection limits were at or below 2 ng/g for 24 of 35 pesticides studied, with recovery between 70 and 125% for 27 pesticides in samples fortified at 10 ng/g. Recovery was not dependent on fat content when measured in laboratory fortified samples containing 1, 5, and 10% fat by weight. Precision over multiple injections was acceptable, with a relative standard deviation of 2.6–15% for 25 analytes.

Determination of Serum Physiological Concentration of Methylmalonic Acid by Gas Chromatography-Mass Spectrometry with Selected Ion Monitoring

1998 ◽  
Vol 35 (5) ◽  
pp. 633-636 ◽  
Author(s):  
Nader Rifai ◽  
Thilo Hagen ◽  
Loetta Bradley ◽  
Masayuki Sakamoto
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Methylmalonic Acid ◽  
Solid Phase ◽  
Rapid Determination ◽  
Gas Chromatography Mass Spectrometry ◽  
Selected Ion Monitoring ◽  
Chromatography Mass Spectrometry ◽  
Wide Range

We developed a sensitive assay for the rapid determination of serum methylmalonic acid concentration using capillary gas chromatography-mass spectrometry (GC/MS) with selected ion monitoring and a simple solid-phase extraction. The assay was linear up to 10 000 nmol/L and had a detection limit < 50 nmol/L, average recovery of 98% and between-day coefficient of variation at concentrations of 570 and 2206 nmol/L of 7.7% and 5.4%, respectively ( n = 25). Comparison with another validated GC/MS method using sera with a wide range of methylmalonic acid concentrations (94-2020 nmol/L) revealed a slope and intercept of 0.97 and 17 nmol/L, respectively ( n = 38). Methylmalonic acid concentrations determined by this assay in a group of apparently healthy individuals ranged from 64–331 nmol/L ( n = 81). We conclude that the method is ideally suited for the determination of methylmalonic acid at physiological concentrations in both clinical and research laboratories.

Residue Analysis of Organophosphorus and Organochlorine Pesticides in Fatty Matrices by Gas Chromatography Coupled with Electron-Capture Detection

2006 ◽  
Vol 61 (5-6) ◽  
pp. 341-346 ◽  
Author(s):  
Jae-Woo Park ◽  
A. M. Abd El-Aty ◽  
Myoung-Heon Lee ◽  
Sung-Ok Song ◽  
Jae-Han Shim
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Simple Procedure ◽  
Linear Regression Analysis ◽  
Residue Analysis ◽  
Electron Capture Detection ◽  
Relative Standard ◽  
Wide Range ◽  
Repeatability And Reproducibility

A multiresidue method for the simultaneous determination of 22 organochlorine (OCs) and organophosphorus (Ops) pesticides (including isomers and metabolites), representing a wide range of physicochemical properties, was developed in fatty matrices extracted from meat. Pesticides were extracted from samples with acetonitrile/n-hexane (v :v, 1:1). The analytical screening was performed by gas chromatography coupled with electron-capture detection (ECD). The identification of compounds was based on their retention time and on comparison of the primary and secondary ions. The optimized method was validated by determining accuracy (recovery percentages), precision (repeatability and reproducibility), and sensitivity (detection and quantitation limits) from analyses of samples fortified at 38 to 300 ng/g levels. Correlation coefficients for the 22 extracted pesticide standard curves (linear regression analysis, n = 3) ranged from 0.998 to 1.000. Recovery studies from 2 g samples fortified at 3 levels demonstrated that the GC-ECD method provides 64.4-96.0% recovery for all pesticides except 2,4′-DDE (44.6-50.4%), 4,4′-DDE (51.1-57.5%) and 2,4′-DDT (50.0-51.2%). Both repeatability and reproducibility relative standard deviation values were < 20% for all residues. Detection limits ranged from 0.31 to 1.27 ng/g and quantification limits were between 1.04 and 4.25 ng/g. The proposed analytical method may be used as a simple procedure in routine determinations of OCs and Ops in meat. It can also be applied to the determination of pesticide multi-residues in other animal products such as butter and milk.

Rapid determination of products of phenol hydrogenation in a supercritical water system using headspace gas chromatography

2015 ◽  
Vol 69 (5) ◽  
Author(s):  
Qing-Qing Guan ◽  
Xiao-Dian Huang ◽  
Yan-Hua Zeng ◽  
Chao-Hai Wei ◽  
Ping Ning ◽  
...  
Keyword(s):  
Supercritical Water ◽  
Rapid Determination ◽  
Reaction System ◽  
Headspace Analysis ◽  
Water System ◽  
Anhydrous Calcium Chloride ◽  
Crystal Water ◽  
Phenol Hydrogenation ◽  
Relative Standard

AbstractThis paper reports a headspace analysis technique for the determination of products, i.e., cyclohexanone (CE) and cyclohexanol (CL), of phenol hydrogenation in a supercritical water reaction system (SWRS) with water removal by hydrate formation. An addition of anhydrous calcium chloride leads to water absorption resulting in crystal water; thus, the samples can be quantitatively measured without the influence of water. After achieving equilibrium at 150­°C and maintaining it for 5 min, the obtained results showed a relative standard deviation of less than 5.3 % and the recovery ranged from 93 % to 104 %. The presented method is simple and accurate for the analysis of CL, CE and phenol in samples from phenol conversion in SWRS.

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