Steroid analysis by gas chromatography with SCOT and wide‐bore WCOT columns

Abstract

AbstractGlass capillary columns are ideal for analysis of urinary steroid profiles (i.e. the total steroid neutral fraction without prior separation into sub‐groups).In this paper performance of both SCOT and wide‐bore WCOT columns has been compared, resulting in no significant quantitative difference on urine extracts run as trimethylsilyl ether derivatives. However, because of increased efficiency the WB‐WCOT column exhibited more sensitivity in measurement of small amounts of 11‐ox‐aetiocholanolone. Sensitivity of other steroids was greatly enhanced by use of either SCOT or WB‐WCOT, leading to an almost tenfold increase over conventional packed columns (e.g. androsterone and aetiocholanolone < 40 μg per 24 h urine sample). A simple splitless injection system (based on a design of Dr. W. Greenaway, Oxford University) is presented.Experiments were also carried out using a SCOT column in conjunction with an FM‐electron capture detector. Whilst efficiency was impaired due to the design of the detector, use of He (carrier) and N2 (make up gas) showed that several steroid derivatives could be easily measured at well below the 10−10 g level with much more rapid retention times than with a 1½m packed column. Highly successful separation of 19 amino acids (as fluoro‐acyl derivatives) was achieved in 35 minutes using a SCOT (30 m) SP2100 column.