Detection of multiple steroidal compounds in synthetic urine using comprehensive gas chromatography-mass spectrometry (GC×GC-MS) combined with a molecularly imprinted polymer clean-up protocol

A method capable of screening for multiple steroids in urine has been developed, using a series of twelve structurally similar, and commercially relevant compounds as target analytes. A molecularly imprinted solid phase extraction clean-up step was used to make the sample suitable for injection onto a GC×GC-MS setup. Significant improvements compared to a commercially available C-18 material were observed. Each individual steroid was able to be separated and identified, using both the retention profile and diagnostic fragmentation ion monitoring abilities of the comprehensive chromatographic-mass spectrometry method. Effective LODs of between 11.7 and 27.0 pg were calculated for individual steroids, effectively equivalent to concentration levels of between 0.234 and 0.540 ng mL−1 in urine, while the application of multiple screen was demonstrated using a 10 ng mL−1 mixed sample. The nature of this study also removes the need for sample derivitisation which speeds up the screening process.