Searchable abstracts of presentations at key conferences in endocrinology

ea0065p365 | Reproductive Endocrinology and Biology | SFEBES2019

Derivatisation of 5α-dihydrotestosterone enhances sensitivity of analysis of human plasma by liquid chromatography tandem mass spectrometry

Faqehi Abdullah , Denham Scott , Naredo-Gonzalezb Gregorio , Cobice Diego , Sabil Ghazali , Upreti Rita , Gibb Fraser , Homer Natalie , Andrew Ruth

Liquid Chromatography tandem mass spectrometry (LC–MS/MS) is gold-standard for androgen analysis in biological fluids, superseding immunoassays in specificity, particularly at low concentrations. While LC–MS/MS is well established for analysis of testosterone (T) and androstenedione (A4), 5α-dihydrotestosterone (DHT) presents greater analytical challenges. DHT circulates at low nanomolar concentrations in men and lower in women, ionising inefficiently. Thus, eve...

ea0034p249 | Obesity, diabetes, metabolism and cardiovascular | SFEBES2014

Derivatisation of estrogens enhances specificity and sensitivity of analysis by liquid chromatography tandem mass spectrometry

Faqehi Abdullah M M , Cobice Diego F , Naredo Gregorio , Mak Tracy C S , Walker Brian R , Homer Natalie Z M , Andrew Ruth

Physiological circulating concentrations of estrogens are very low in men and postmenopausal women (<50 pg/ml), which presenting analytical challenges. Immunoassays can detect as low as 30 pg/ml, but cross-reactivity is a concern. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) offers greater specificity than immunoassays, but ionisation of estrogens is inefficient. Derivatisation, which introduces charged moieties, may enhance ionisation. Dansylated de...