An inter-laboratory study of detection limits in the analysis of water and wastewater for organo-chlorine pesticides by liquid/liquid extraction and gas chromatography-electron capture detector (USEPA Method 608)

2011 ◽  
Vol 91 (10) ◽  
pp. 960-977
Author(s):  
David Eugene Kimbrough
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Laboratory Study ◽  
Detection Limits ◽  
Liquid Extraction ◽  
Electron Capture Detector ◽  
Liquid Liquid Extraction ◽  
Water And Wastewater

Determination of Bromate Ions in Drinking Water by Derivatization with 2-Methyl-2-Butene, Dispersive Liquid-Liquid Extraction and Gas Chromatography-Electron Capture Detection

2020 ◽  
Vol 103 (5) ◽  
pp. 1243-1249
Author(s):  
Mehdi Nabi ◽  
Sayed Mehdi Ghoreishi ◽  
Mohsen Behpour
Keyword(s):  
Gas Chromatography ◽  
Detection Limit ◽  
Electron Capture ◽  
Liquid Extraction ◽  
International Standards ◽  
Electron Capture Detection ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Derivatizing Agent

Abstract Background A simple, rapid, selective and sensitive sample preparation and derivatization method was performed for determination of bromate ions in water by means of dispersive liquid-liquid extraction (DLLE) by gas chromatography-electron capture detection (GC-ECD). This method is based on 2-methyl-2-butene derivatization by bromine produced from bromate ions in acidic medium and extraction by n-hexane. Objective Derivatizing agent: It is cheap and available and it has high efficiency in reaction with Br2. Simplicity: Preparation and extraction process don't need to any specific equipment and procedure is completely simple and fast. Limit of detection: DL is as low as 0.43 µg/L. Methods Various effective factors on the derivatization and extraction efficiency, such as amount of derivatizing agent, volume of extraction solvent, bromide concentration, volume and concentration of sulfuric acid, type and volume of extracting and dispersing solvent, ionic strength, storage time before extraction and ECD makeup-gas flow rate were investigated. Results Under the optimum conditions, the method had a linear calibration curve ranging from 1.0 to 200.0 µg/L for bromate ions with a determination coefficient (R2) of 0.994 and the detection limit was 0.43 µg/L. The recovery percent and relative standard deviation for the determination of 1.0, 5.0 and 50.0 µg/L bromate ion was between 90 and 110%, and 3.0 and 8.0% (n = 3), respectively. Conclusions Finally, the method was successfully applied for the preconcentration and determination of bromate ions in water samples, and satisfactory results were obtained. Highlights (1) Fast, easy, accurate and economical innovative analysis of bromate ions in water and wastewater. (2) Determination of inorganic ion by GC-ECD after derivatization (3) Low detection limit (4) Optimization of different method parameters to obtain accurate results based on requirements of international standards, specifically ISO/IEC 17025.

Gas Chromatographic Determination of N-Butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-toluidine and α,α,α-Trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine in Formulations

1971 ◽  
Vol 54 (3) ◽  
pp. 711-712
Author(s):  
Martha Fuzesi
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Electron Capture ◽  
Chromatographic Method ◽  
Chromatographic Determination ◽  
Electron Capture Detector ◽  
Reference Solution ◽  
Gas Chromatographic Method

Abstract A gas chromatographic method is described for the quantitative determination of N-butyl-N-ethyl-α,α,α-trifluoro-2,6-dinitro-p-tolindine and α,α,α-trifluoro-2,6-dinitro-N,N-dipropyI-p-toluidine herbicides in formulations. The sample is extracted with benzene, and equal amounts of sample and reference solution in the same concentration range are analyzed by gas chromatography, using an electron capture detector and an SE-30/Diatoport S column. The method has been applied successfully to laboratory-prepared and commercial samples.

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