Ultra-short open capillary columns in gas-liquid chromatography.

New area in capillary gas chromatography (GC) was investigated. Many important analytical tasks can be solved only use very short capillary columns. Variation of chromatographic characteristics of ultra-short capillary columns with column length was originally studied at the conditions of gas-liquid chromatography. The column length varied from 500 to 10 cm. Dependencies of height equivalent to one theoretical plate (HETP) and separation number (SN) on carrier gas velocity were considered for columns of various length. Field of ultra-short open capillary columns in gas-liquid chromatography has the following peculiarities: (1) more shorter retention times of sorbates, (2) more low temperatures of short column, that has as final result (a) high selectivities of used column and (b) the possibilities to separation more thermal lability compounds. It was shown that short capillary columns can be successfully used at both isothermal and temperature programming conditions for express-analysis at lower oven temperatures. Examples of express-analysis (high speed), analysis of high boiling and thermolabile compounds are listed, which demonstrate some radically new applications of capillary gas chromatography.