Trace Analysis on Capillary Columns. Selected Practical Applications: Insecticides in Raw Butter Extract; Aroma Head Space from Liquors; Auto Exhaust Gas

Abstract

Trace analysis on capillary columns becomes feasible provided appropriate injection techniques without stream splitting are used. To demonstrate potentialities and limitations of the methods, we investigated practical applications, the conditions of which were as dissimilar as possible. Insecticides in dairy products can be estimated by direct analysis of the raw petrol ether extract, without previous purification by column chromatography. 2-4 9 1 of extract are injected without splitting en a short inlet capillary fitted in a separate injection bloc. The inlet capillary is then connected to the capillary column mounted in the column oven with electron capture detector. Analysis is started by rapid heating to a constant temperature or by temperature programming resp. Head space analysis is another case in which trace components are important. Whereas several workers reported trapping of head space vapors in capillaries at low temperatures, we emphasize avoiding candensation, e.g. of water vapor, in the capillary. Al] sampling is done, therefore, near the original temperature of the head space material, i.e. at room temperature. In the case of coqnac aroma analysis in which most of the water and ethanol vapor are vented through the inlet capillary, the influences of most sampling variables-gas volume, length of inlet capillary-are studied. In the analysis of auto exhaust gas, again, bypassing of water is an important detail. In additien to hydrocarbons originating directly from the fuel as investigated by several authors, we found many combustion and conversion products, primarily naphthaline derivatives and phenols.

High resolution gas chromatography of tobacco smoke: The contributions of kurt grob

“…The first difficulty was partially overcome by the use of an elongated septum cap [37]. However, both problems could be completely surmounted only through establishing a controlled leak by introducing a needle through the septum at the end of the splitless period [35].…”

Characteristics and performance of gas chromatographic detectors with glass capillary columns

“…Brechbuler [3] reported the development of a low volume electron capture detector which was designed specifically for capillary GC. Otherwise, the papers in the literature principally describe the application of GC detectors to capillary column analyses [2,4,11,12]. This paper will treat the specifics of capillary GC detector design, response, and performance characteristics.…”