| A LC/MS/MS method was developed to quantify the free and conjugated forms of testosterone (T) and epitestosterone (E) using isotope dilution techniques for the purpose of measuring T/E ratios. The method produced an LOD of 0.01 and LOQ of 0.05 ng/mL, respectively, for both T and E. Poor reproducibility and accuracy of female urine T/E ratios was primarily due to ion suppression effects, especially of the E isomer. Experiments to identify and to minimize the source of the suppression using sample cleanup procedures will be discussed. |
|
