scholarly journals Determination of Chlordane and Chlorpyrifos in Ambient Air at Low Nanogram-Per-Cubic Meter Levels by Supercritical Fluid Extraction

1997 ◽  
Vol 80 (1) ◽  
pp. 74-78 ◽  
Author(s):  
Kamal Swami ◽  
Amarjit S Narang ◽  
Rajinder S Narang
Keyword(s):  
Carbon Dioxide ◽  
Gas Chromatography ◽  
Supercritical Fluid Extraction ◽  
Supercritical Fluid ◽  
Electron Capture ◽  
Capillary Gas Chromatography ◽  
Ambient Air ◽  
Electron Capture Detection ◽  
Hewlett Packard

Abstract A method for the determination of termiticides present in ambient air was simplified by modifying the extraction thimbles used in the Hewlett-Packard supercritical fluid extractor so they could be used for collection as well as extraction of termiticides. The method was applied to the determination of chlorpyrifos and technical chlordane. The termiticides were trapped on cartridges containing Florisil and foam plugs, extracted with carbon dioxide in the supercritical fluid extractor, and determined by capillary gas chromatography with electron capture detection. On the basis of a 20 m3 sample, detection limits were 0.1 ng/m3 for chlorpyrifos and 1.0 ng/m3 for technical chlordane.

Determination of Type A and B Trichothecenes in Cereals by Gas Chromatography with Electron Capture Detection

1992 ◽  
Vol 75 (6) ◽  
pp. 1049-1053 ◽  
Author(s):  
Tord E Möller ◽  
Håkan F Gustavsson
Keyword(s):  
Gas Chromatography ◽  
Ethyl Acetate ◽  
Electron Capture ◽  
Capillary Gas Chromatography ◽  
Quantitative Method ◽  
Type A ◽  
Electron Capture Detection

Abstract A quantitative method has been developed for determination of nonmacrocyclic trichothecenes in cereals. The mycotoxins are extracted with acetonitrile- ethyl acetate-water, and the extracts are quickly defatted with hexane and purified on a Sep- Pak Florisil cartridge. The trichothecenes are then silylated with Tri-Sil/TBT and quantitated by capillary gas chromatography with electron capture detection. High recoveries of 13 tested trichothecenes were achieved in experiments on wheat at the 250 μg/kg level. The method was also tested on barley, maize, oats, and rye with good results

Surrogate-Assisted Determination of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin in Fish by Electron Capture Capillary Gas Chromatography

1986 ◽  
Vol 69 (6) ◽  
pp. 976-980
Author(s):  
Richard A Niemann
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Capillary Gas Chromatography ◽  
Capillary Column ◽  
Electron Capture Detection ◽  
Matrix Interference ◽  
Relative Standard ◽  
Tetrachlorodibenzo P Dioxin ◽  
Liquid Chromatographic

Abstract Surrogate spiking the sample with 1000 parts per trillion (pptr) 1,3,7,8-tetrachlorodibenzo-p-dioxin (1378-TCDD) has doubled analytical throughput in determining toxic 2378-TCDD (analyte) at the low partper- trillion level in fish, using multicolumn high resolution liquid chromatographic cleanup before quantitation by capillary gas chromatography with electron capture detection. The 1378- and 2378-TCDD were recovered equally and were well separated by the capillary column so that the earlier-eluting surrogate did not interfere with the quantitation of levels of analyte many-fold lower. Matrix interference contributed <1 % bias in surrogate quantitation. Using surrogate recovery to correct for analyte losses during analysis, accuracy averaged (n = 7) 105% in determining 18 or 45 pptr 2378-TCDD added to fish without detectable bioincurred analyte. Analyses of selected fish with bioincurred 2378-TCDD gave results comparable to earlier work where recovery correction required a second analysis of sample fortified with analyte. With surrogate fortification, repeatability of determination (n = 3 or 4) improved markedly to <5% relative standard deviation at 37-46 pptr.

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