Search results for "Capillary gas chromatography"
showing 10 items of 12 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 …
Determination of biogenic amines in meat by combined ion-exchange capillary gas chromatography
1984
Abstract A procedure is described for the determination of putrescine, cadaverine and histamine in meat. Crude perchloric acid extracts were pre-separated on a weakly acidic cation exchanger and the amines quantified by capillary gas chromatography. The diamines were analysed as trifluoroacetyl derivatives and histamine was converted into N α -trifluoroacetyl-N τ -ethoxycarbonylhistamine. The accuracy of the determination of diamines was examined by a precipitation pre-separation method and by mass fragmentometric quantification. The proposed procedure allows the sensitive, sufficiently precise and highly specific determination of putrescine and cadaverine in meat.
Identification and quantitation of trace amounts of barbiturates with glass capillary gas chromatography
1979
Pre-chromatographic reactions are no longer a necessary evil. Equipment such as the microrefluxer now allows reproducible 7-μl-reactions to be carried out in a short time. Thus multiple derivatisations can be used together with glass capillary GC for routine identifications. The method has been succesfully applied to barbiturates. Retention data of their methyl-, allyl- and benzyl-derivatives are given. Quantitative blood level determinations are briefly discussed.
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…
Glass capillary gas chromatography of chlorinated methyl acetates, propanoates and butanoates on Carbowax 20M and SE-30 columns
1982
The gas chromatography of all chlorinated methyl acetates, methyl propanoates and methyl mono- and dichlorobutanoates has been studied on Carbowax 20M and SE-30 glass capillary columns under various running conditions. The order of elution on a non-polar column was largely determined by the boiling point of esters, whereas on a polar column it was much influenced by the structure of compounds. Complete separation of the combined mixture of all 27 compounds could not be achieved, however, methyl 3,3-dichlorobutanoate was the only ester overlapped on both columns in spite of the various column temperatures used. The best separation of the mixture was on Carbowax 20M with a temperature program…
Glass-capillary gas chromatography of chlorobenzenes on SE-30 and Carbowax 20M columns. Simultaneous determination of chlorobenzenes and chlorophenols
1983
Gas chromatography of benzene and all chlorobenzenes has been studied on SE-30 and Carbowax 20M glasscapillary columns under various operating conditions. The benzene isomers are eluted on both columns according to their boiling points. Separation of all components in a mixture is achieved on Carbowax 20M, whereas on SE-30 the peaks of closely related isomers overlapped. Also one partial overlapping is observed on a non-polar phase. The relative retention times for compounds are given and the retention order is discussed. The retention behaviour of chlorobenzenes and chlorophenols is compared. By using an SE-30 quartz-capillary column a mixture of 33 individual components gives 29 resolved …
Glass capillary gas chromatography of methyl, methyl 2-chloro and chloromethyl esters of C2-C20n-carboxylic acids
1981
Wine analysis: Study and comparison of techniques developed for the study of volatile constituents
1986
A number of headspace techniques have been compared, using a standard solution containing 12 compounds and a wine sample, viz.: (1) purge and cold trap injection; (2) dynamic headspace combined with liquidliquid extraction; (3) static headspace with and without preconcentration; (4) direct liquid injection. The sensitivity, reproducibility and speed of analysis were determined. Considering the results obtained and dependent on the purpose of the experiments and the number of samples to be examined the appropriate technique can be selected. ?? 1980 Friedr. Vieweg & Sohn Verlagsgesellschaft mbH.