Endocrine Abstracts

Steroids present in human serum can be used to identify a number of conditions such as congenital adrenal hyperplasia, Addison’s disease and Cushing’s disorder. Historically this has been completed using immunoassays; currently there is a move towards mass spectrometry which reduces analysis time, cross reactivity and improves sensitivity. When mass spectrometers are coupled with liquid chromatography systems (LC–MS) it is possible to monitor a number of steroids in a single assay. Problems with inter-laboratory variation of LC–MS results can lead to errors when analysing nationwide data sets. Implication of a kit with its own mass spectrometry parameters such as sample preparation methods, columns, solvent additives and mass transitions should reduce inter-laboratory variation.

Recent introduction of a 10 steroid serum kit (Perkin-Elmer) has been completed, due to the number of different mass spectrometers available these kits needs to be thoroughly tested on a number of systems to ensure comparability. The viability of the Perkin-Elmer 10 steroid CHS MSMS kit was examined on a Waters Xevo TQ mass spectrometer with an Acquity UPLC system. We carried out concurrent analysis over a range of concentrations for each steroid: aldosterone (0.8–18 nmol/l), androstenedione (0.3–74 nmol/l) corticosterone (1–204 nmol/l), cortisol (5–1008 nmol/l), DHEA (1–255 nmol/l), DHEAS (37–7557 nmol/l), 11-deoxycortisol (0.2–54 nmol/l), 17-hydroxyprogesterone (0.5–77 nmol/l), progesterone (0.5–91 nmol/l) and testosterone (0.1–26 nmol/l). The method was validated through investigation of spiked serum (Randox) and sera of healthy volunteers. Concurrent analysis of 10 steroids using LC–MS was completed with reliable quantitation in <15 min. For optimum results using a Xevo mass spectrometer a number of parameters were adjusted, for example the ESI source was superior to the APCI and some mass transitions were altered.

The concurrent analysis of multiple steroids in a single LC–MS run demonstrates a major advance in the fast reliable diagnosis of steroid related disorders, which can be employed in clinical laboratories.