Ultra sensitive measurement of endogenous epinephrine and norepinephrine in human plasma by semi-automated SPE-LC-MS/MS.

Measurement of endogenous epinephrine (E) and norepinephrine (NE) in human plasma is very challenging due to lower endogenous concentrations as compared with animal plasma. An LC-MS/MS in combination with alumina-based SPE and derivatization procedure was validated for the measurement of E and NE in human plasma with acceptable intra-day and inter-day accuracy and precision. Sample was extracted with semi-automated alumina 96-well solid phase extraction (SPE) cartridge. The resulting eluent was dried and derivatized using d4-acetaldehyde. The analytes were separated on a monolithic C(18) column. Extraction efficiencies were >66% for E and NE. The lower limit of quantitation (LLOQ) was 5.00 pg/mL for E and 20.0 pg/mL for NE.