Feasibility of capillary liquid chromatography/microchip atmospheric pressure photoionization mass spectrometry in analyzing anabolic steroids in urine samples

We examined the feasibility of capillary liquid chromatography/microchip atmospheric pressure photoionization tandem mass spectrometry (capLC/μAPPI-MS/MS) for the analysis of anabolic steroids in human urine. The urine samples were pretreated by enzymatic hydrolysis (with β-glucuronidase from Helix pomatia), and the compounds were liquid-liquid extracted with diethyl ether. After separation the compounds were vaporized by microchip APPI, photoionized by a 10 eV krypton discharge lamp, and detected by selected reaction monitoring. The capLC/μAPPI-MS/MS method showed good sensitivity with detection limits at the level of 1.0 ng mL^-1, good linearity with correlation coefficients between 0.9954 and 0.9990, and good repeatability with relative standard deviations below 10%. These results demonstrate that microchip APPI combined with capLC/MS/MS provides a new potential method for analyzing non-polar and neutral compounds in biological samples.