Search results for "Gas liquid chromatographic"
showing 8 items of 8 documents
Gas-liquid chromatographic analyses
1983
Abstract The gas chromatography of mixtures of n -alkyl acetates (CH 3 COOR, R = C 1 —C 8 ) and methyl esters of aliphatic n -carboxylic acids (R′COOCH 3 , R′ = C 1 —C 8 ) and certain of their monochlorinated derivatives has been studied on Carbowax 20M and SE-30 glass capillary columns under the same operating conditions. The separation of the isomeric monochlorinated esters was complete on Carbowax 20M, whereas on SE-30 the peaks of 6- and 7-chlorooctyl acetates and methyl (ω − 1)- and (ω − 2)-chlorooctanoates and -nonanoates partly overlapped. The complete separation of the mixtures could not be achieved, however, on Carbowax 20M, in spite of the use of various operating conditions. The …
Gas—liquid chromatographic analyses
1984
Abstract The gas chromatography (GC) of n -alkyl acetates (CH 3 COOR), chloroacetates (CH 2 ClCOOR), dichloroacetates (CHCl 2 COOR) and trichloroacetates (CCl 3 COOR), where the alcohol chain length (R) varied between 1 and 8, and certain of their monochlorinated derivatives, 176 compounds altogether, has been studied on SE-30 and OV-351 glass capillary columns under the same operating conditions. The isomeric monochlorinated esters are eluted in direct order from the 1- chloro to the ω-chloro isomer, the separation of the isomers being complete on OV- 351. On SE-30, however, the peaks of the 6- and 7-chlorooctyl esters are partly overlapped. The separation of the mixtures of odd- and e…
Gas-liquid chromatographic analyses
1985
Gas—liquid chromatographic analyses
1984
Abstract The gas choromatographic retention behaviour of veratrole and all nine chlorinated veratroles was studied on SE-30 and OV-351 capillary columns. Temperature programming from 100°C at 6°C min−1 and isothermal operation at 140, 160, 180 and 200°C were used. The complete separation of a mixture was obtained on SE-30, the isomers being eluted in order of their degree of chlorination. On OV-351, however, the 3,4,5-trichloro and tetrachloro isomers overlap with temperature programming, being separated at 140, 160 and 200°C. Retention indices and increments of retention indices for each position of substitution are examined and the effect of increasing temperature on retention is discusse…
Gas-liquid chromatographic analyses of chlorination products of propionyl chloride
1981
Abstract Photochlorination of propionyl chloride with chlorine in the liquid phase at room temperature gives all eleven chloropropionyl chlorides from the mono-to the pentachloro isomer. The process was investigated every 2 h by gas-liquid chromatography, and the products were identified and estimated as their methyl esters by comparison with model compounds. The isomer distribution of the products was studied in detail. Because the process favours the 3-position, the main components were 3-chloropropionyl chloride up to 15 h, 3,3-dichloropropionyl chloride between 15 and 29 h, 3,3,3-trichloropropionyl chloride between 29 and 56 h and pentachloropropionyl chloride after 56 h of chlorination.
Gas-liquid chromatographic analyses
1984
A mixture of all nine chlorinated 4-hydroxybenzaldehydes and the parent homologue was separated on a non-polar SE-30 capillary column using various isothermal and temperature-programmed operating conditions. The relative retention data for the compounds are given and the retention indices together with the retention index increments for each position of chlorine substitution are examined. The retention order 3-Cl<parent<2,5-di-Cl<2,3-di-Cl<3,5-di-Cl<2-Cl<2,3,5-tri-Cl<2,3,6-tri-Cl<2,6-di-Cl<tetra-Cl isomer obtained indicates that the effect of the position of substitution on the retention behaviour is greater than that of the number of chlorine atoms. The retention is maximal with 2-Cl and 2…
Gas—liquid chromatographic analyses
1985
Abstract The gas chromatographic retention behaviour of methylethyl, 1-methylpropyl, 2-methylpropyl, 1,2-dimethylpropyl, 1-methylbutyl and 3-methylbutyl esters of benzoic and o-, m- and p-chlorobenzoic acids on low-polarity (SE-30) and polar (OV-351) capillary columns under several temperature-programmed and isothermal conditions is reported. The retention data and the Kovats retention indices for all 24 components are given and the separation of a complex mixture is discussed. The retention index increments have been used to examine the effects of chain branching and chlorine substitution. The results are compared with those for n-alkyl benzoates and monochlorobenzoates.
Gas—liquid chromatographic analyses
1989
Abstract The retention (I), dispersion (IM) and selectivity (I*) indices of sixteen polychlorinated dibenzo-p-dioxins and fourteen polychlorinated dibenzofurans were determined on a low-polarity HP-5 capillary column using a gas chromatograph connected with an ion-selective detector. IM and I* values were also calculated for all 73 dibenzo-p-dioxins from the di- to the octachloro isomer and for all possible 135 chlorinated dibenzofurans based on the predicted retention index data reported earlier. The effect of the position of chlorination is shown and the results are compared with those for several series of chlorinated aromatics.