Quantitation of Polychlorinated Biphenyl Residues by Electron Capture Gas-Liquid Chromatography: Reference Material Characterization and Preliminary Study

1978 ◽  
Vol 61 (2) ◽  
pp. 272-281
Author(s):  
Leon D Sawyer
Keyword(s):  
Electron Capture ◽  
Material Characterization ◽  
Chemical Ionization ◽  
Polychlorinated Biphenyl ◽  
Collaborative Study ◽  
Gas Liquid Chromatography ◽  
Ionization Mass ◽  
Preliminary Study ◽  
The Individual ◽  
Liquid Chromatographic

Abstract Weight per cent compositions of individual peaks of Aroclors 1016, 1242, 1248, 1254, and 1260 were determined under standard gas-liquid chromatographic (GLC) conditions. The GLC peak compositions were determined by using a Hall electrolytic conductivity detector for chlorine measurement and chemical ionization mass spectrometry with single ion monitoring for molecular weight characterization. The Aroclors used are available as reference materials for individual peak quantitation of polychlorinated biphenyl (PCB) residues by electron capture GLC. On the basis of a limited interlaboratory study and a collaborative study, the individual peak method shows improved interlaboratory precision and/or accuracy in PCB quantitation over existing methods.

Quantitation of Polychlorinated Biphenyl Residues by Electron Capture Gas-Liquid Chromatography: Collaborative Study

1978 ◽  
Vol 61 (2) ◽  
pp. 282-291
Author(s):  
Leon D Sawyer
Keyword(s):  
Electron Capture ◽  
Polychlorinated Biphenyl ◽  
Collaborative Study ◽  
Peak Height ◽  
Gas Liquid Chromatography ◽  
Chicken Fat ◽  
Fortified Milk ◽  
Significant Difference ◽  
The Individual ◽  
Liquid Chromatographic

Abstract Ten collaborators quantitated 2 synthetically prepared polychlorinated biphenyl (PCB) mixtures, 2 PCB-fortified milk samples, and an incurred PCB residue in milk and chicken fat. Three electron capture gas-liquid chromatographic (GLC) methods were used for quantitating each unknown PCB against Aroclor reference materials. Two of the methods were existing AOAC total response comparisons and the third was a proposed individual peak comparison. In addition, existing AOAC multiresidue pesticide methodology was employed for determining PCB recovery from whole milk. The average combined recovery of Aroclor 1254 from milk fortified at 1.4 and 2.7 ppm (fat) was approximately 85% (coefficient of variation, 15%) with no significant difference by the methods of quantitation. The incurred PCB residue in milk (as 1254) was determined to be 1.3 (30%), 1.7 (31%), and 1.2 ppm (18%) by total peak height, total area, and individual peak quantitation methods, respectively. In the same order, incurred PCB in chicken fat was determined to be 6.8 (13%), 7.5 (16%), and 5.6 ppm (8%) as 1242, or 6.9 (6%), 5.9 (8%), and 6.3 ppm (8%) as 1248. Total PCB quantitated individually in a 3- and a 4-component chlorobiphenyl mixture, using 1248 as the reference standard, resulted in the following averages of actual amounts present: 3-component—109% (23%), 95% (18%), and 95% (6%); 4-component— 116% (16%), 112% (29%), and 104% (7%), respectively, for total peak height, total area, and individual peak quantitation methods. Both the individual peak quantitation method and the AOAC multi-pesticide methodology have been adopted as official first action methods for PCB.

Sensitive Gas-Liquid Chromatographic Method for Asulam Residues in Peaches

1980 ◽  
Vol 63 (3) ◽  
pp. 511-516
Author(s):  
Promode C Bardalaye ◽  
Neal P Thompson ◽  
David A Carlson
Keyword(s):  
Analytical Method ◽  
Chemical Ionization ◽  
Parent Compound ◽  
Coupling Reaction ◽  
Gas Liquid Chromatography ◽  
Ionization Mass ◽  
Liquid Chromatographic Method ◽  
The Common ◽  
Liquid Chromatographic ◽  
Colorimetric Procedure

Abstract The current analytical method for determining residues of the herbicide asulam (methyl (4-aminobenzenesulfonyl) carbamate) is the nonspecific colorimetric procedure based on the coupling reaction of N-1-naphthylethylenediamine with the diazotized amine. A new analytical method for determining the residues of this herbicide and its 2 known major metabolites, acetylasulam and sulfanilamide, in peaches has been developed and evaluated using gas chromatography with an N-P detector. The method is based on the hydrolytic conversion of the parent compound and the known metabolites to the common product sulfanilamide which is then analyzed by gas-liquid chromatography as its per N-methylated derivative. The identity of the derivative has been confirmed by chemical ionization mass spectrometry. The method was tested by using fortified crop extracts and also by analyzing crop treated by postemergent application of the herbicide for weed control. Sensitivity of the method is 5 ng and the detection limit in the crop is 0.1 ppm. Recoveries ranged from 70 to 80% from peaches at fortification levels of 1, 5, and 10 ppm. At a fortification level of 0.1 ppm the recovery is 50-60%.

Collaborative Study of the Gas-Liquid Chromatographic Determination of Coumarin (1,2-Benzopyrone) in Wine

1976 ◽  
Vol 59 (4) ◽  
pp. 780-782
Author(s):  
Randolph H Dyer ◽  
Glenn E Martin
Keyword(s):  
Collaborative Study ◽  
Chromatographic Determination ◽  
Chloroform Extract ◽  
Gas Liquid Chromatography ◽  
Individual Values ◽  
Significant Difference ◽  
Liquid Chromatographic Determination ◽  
The Individual ◽  
Liquid Chromatographic

Abstract The determination of coumarin in wine by using gas-liquid chromatography of a chloroform extract was collaboratively studied. Eleven collaborators analyzed 6 samples: 3 containing 4.0 mg coumarin/L, 2 containing 8.0, and 1 containing 0.0. When the triplicate and duplicate recoveries for the 4.0 and 8.0 levels were averaged and treated singly for the collaborators, there was no statistically significant difference in the accuracy between the 2 levels. However, the accuracy for the 4.0 level was much better than that for the 8.0 level: 100.0 vs. 105.9%. An analysis of the individual values showed no significant differences among collaborator means at the 4.0 level, while there was a significant difference among means at the 8.0 level. All collaborators were within the allowable score limits in the ranking test. The method was adopted as official first action.

Electron capture gas-liquid chromatographic-mass spectral identification of acids produced by Neisseria meningitidis in a defined medium

1979 ◽  
Vol 9 (1) ◽  
pp. 97-102
Author(s):  
C C Alley ◽  
J B Brooks ◽  
D S Kellogg
Keyword(s):  
Liquid Chromatography ◽  
Neisseria Meningitidis ◽  
Electron Capture ◽  
Defined Medium ◽  
Gas Liquid Chromatography ◽  
Mass Spectral ◽  
Spectral Identification ◽  
Acid Metabolites ◽  
Liquid Chromatographic ◽  
Chromatographic Mass

The acid metabolites and the cellular fatty acids of three strains of Neisseria meningitidis grown in a chemically defined liquid medium were determined with computerized frequency-pulsed electron capture gas-liquid chromatography. Five acids not previously reported were subsequently identified: isobutyric, octanoic, decenoic (C10:1), dodecenoic (C12:1), and tetradecenoic (C14:1). These acids were produced during active metabolism and were not detected as cellular constituents. The frequency-pulsed electron capture gas-liquid chromatography methods which we used provide a rapid, reliable, sensitive means of detecting both these and other metabolic and cellular acids in spent culture medium.

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