Separation of urinary steroids by gas-liquid chromatography on packed and mixed-bed columns

Gas-liquid chromatography (GLC) is one of the most widely used and effective techniques for group analysis of hormonal steroids. Packed columns with liquid phases OV-1, OV-17 and SE-30 are most often used and are most thermally stable. OV-1 methylsiloxane polymer is a non-selective phase employed for separating steroids according to their molecular weights and shapes. The selective phase OV-225 is a methylphenylpolysiloxane containing 75% of phenyl groups: it is used for further differentiation of functional groups of steroid molecules. We mixed nine parts of OV-1 (1%) and one part of OV-225 (3%) both on Gas-Chrom Q (100-120 mesh) and thus obtained a mixed-bed column, which enabled a higher degree of separation of some clinically important steroid metabolites.