Determination of Propylene Glycol in Cosmetics by Gas Chromatography

1967 ◽  
Vol 50 (6) ◽  
pp. 1284-1286
Author(s):  
Frederick C Gross ◽  
John H Jones
Keyword(s):  
Gas Chromatography ◽  
Propylene Glycol ◽  
The Other ◽  
Porapak Q ◽  
Hydrogen Flame ◽  
Flame Detector

Abstract Propylene glycol in cosmetics can be determined by co-distillation in water followed by GC measurement of the distilled propylene glycol on a Porapak Q column and a hydrogen flame detector. The procedure has been successfully applied to a number of commercial samples; 14 of 15 sample recoveries were between 95 and 102%, the other recovery was 92%.

Gas Chromatographic Analysis of Pesticide Formulations

1964 ◽  
Vol 47 (2) ◽  
pp. 259-264
Author(s):  
J P Barrette ◽  
R Payfer
Keyword(s):  
Gas Chromatography ◽  
Chromatographic Analysis ◽  
Operating Conditions ◽  
Relative Retention ◽  
Pesticide Formulations ◽  
Routine Basis ◽  
Hydrogen Flame ◽  
Flame Detector ◽  
Commercial Pesticide

Abstract Although gas chromatography is associated with the determination of pesticide residues, the technique is also useful for analysis of commercial pesticide formulations. For 0.1—2.0% test solutions, high attenuations are used with very sensitive detectors such as the hydrogen-flame detector. Provided a standard of known purity is available for each pesticide examined, a large number of pesticides can be analyzed on a routine basis. The relative retention times for more than 60 pesticides are given for two sets of operating conditions. This tabulation can be used to predict whether any given component of a mixture can be readily estimated.

scholarly journals The Use of Cryogenic Temperature Gas Chromatography for the Determination of Carbon Monoxide and Carbon Dioxide in Cigarette Smoke

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
G.P. Morie ◽  
C.H. Sloan
Keyword(s):  
Carbon Dioxide ◽  
Gas Chromatography ◽  
Carbon Monoxide ◽  
Liquid Nitrogen ◽  
Cigarette Smoke ◽  
Cryogenic Temperature ◽  
Chromatographic Method ◽  
Porapak Q ◽  
Gas Chromatographic Method

AbstractA gas chromatographic method for the determination of carbon monoxide and carbon dioxide in cigarette smoke was developed. A column containing Porapak Q packing and a cryogenic temperature programmer which employed liquid nitrogen to cool the column to subambient temperatures was used. The separation of N

Improved Method for Determination of Chlorophenoxy Acid Residues in Total Diet Samples

1971 ◽  
Vol 54 (4) ◽  
pp. 966-969 ◽  
Author(s):  
George Yip
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
The Other ◽  
Improved Method ◽  
Total Diet ◽  
Chlorophenoxyacetic Acid ◽  
Isothermal Gas

Abstract Modifications to an earlier procedure for chlorophenoxyacetic acid residues are introduced to provide better recoveries, cleaner samples, and sensitivities down to 0.02 ppm. These changes include (1) extracting with acetonitrile or CHCI3, (2) more effective methylation of the acids, (3) Florisil chromatography to separate PCP from the other herbicides, and (4) isothermal gas chromatography by electron capture or microcoulometric detection. The improved procedure was compared with the previous one, using several total diet composites at fortification levels of 0.01–0.05 ppm. Results showed that usable chromatograms were obtainable only with the improved procedure. Recovery studies were made on all commodity groups except for fats, oils, and shortenings. Microcoulometric results were good. Compounds studied were MCP, 2,4-D, 2,4,5-T, 2,4,5-TP, 2,4-DB, PCP, and 2,3,6-TBA.

Inverse gas chromatographic characterization of Porapak Q as an extractant of pollutants from aqueous media

2009 ◽  
Vol 63 (3) ◽  
Author(s):  
Nagy Moustafa ◽  
Doaa El-Desouki
Keyword(s):  
Gas Chromatography ◽  
Chemical Structure ◽  
Inverse Gas Chromatography ◽  
Aqueous Media ◽  
Lewis Acidity ◽  
Porapak Q ◽  
Chromatographic Characterization ◽  
Surface Lewis Acidity

AbstractThe surface of Porapak Q was characterized by inverse gas chromatography (IGC) carried out by the determination of dispersive and specific adsorption components of Porapak Q surface, calculating γsd and -ΔH as parameters, respectively. An interpretation was given based on the chemical structure of Porapak Q. The obtained results were confirmed through the surface Lewis acidity and basicity constants, K a and K b, respectively, correlating well with the determined thermodynamic parameters.

Determination of Methylene Chloride, Ethylene Dichloride, and Trichloroethylene as Solvent Residues in Spice Oleoresins, Using Vacuum Distillation and Electron Capture Gas Chromatography

1975 ◽  
Vol 58 (5) ◽  
pp. 1062-1068
Author(s):  
B Denis Page ◽  
Barry P C Kennedy
Keyword(s):  
Gas Chromatography ◽  
Electron Capture ◽  
Vacuum Distillation ◽  
Methylene Chloride ◽  
Internal Standard ◽  
Ethylene Dichloride ◽  
Porapak Q ◽  
Solvent Residues ◽  
Carrier Solvent

Abstract A quantitative gas chromatographic (GC) method is described for the determination of residual methylene chloride, ethylene dichloride, and trichloroethylene in spice oleoresins. The proposed method involves vacuum distillation in a closed system with toluene as a carrier solvent. Quantitation by electron capture GC on Porapak Q is facilitated by water extraction and by the addition of trans-l,2-dichloroethylene as an internal standard. Recoveries from oleoresins spiked at 30, 15, and 6 ppm ranged from 93 to 102%. To assess the possibility of interference from spice volatiles, the procedure was applied to 17 different spice oleoresins from 3 different manufacturers. No interferences were found, but methylene chloride levels up to 83 ppm and ethylene dichloride levels up to 23 ppm were detected. Trichloroethylene was not detected in any of the oleoresins.

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