Capillary gas chromatography of s-triazines

Abstract

In order to achieve better resolution and lower detection limits for s-triazines, glass capillary columns made of soft soda-lime glass and etched with gaseous hydrogen chloride have been introduced. Columns with non-polar (OV-101, SE-30) mixed (Carbowax 20M + SE-30) and polar stationary liquids (Carbowax 20M) were used. The thickness of the ultra-thin film columns was determined by weighing the capillaries before and after coating of the capillary with stationary phase and conditioning, and varied from 0.05 to 0.5 μm. From the capacity ratios of s-triazines and n-alkanes measured in sections of an originally long dynamically coated column after it had been cut into several equal parts, the constancy of the film thickness along the whole column was judged. The film thickness was not uniform and increased along the whole column. It was found that glass capillary columns with non-polar stationary phase are not very suitable for the analysis of s-triazine herbicides, as tailing occurs with some of them. Symmetrical peaks and the separation of 17 from 18 analysed s-triazines were achieved on glass capillary columns coated with Carbowax 20M.