1993 Volume 9 Issue 5 Pages 631-635
A thermospray high-performance liquid chromatography-mass spectrometry (TSP HPLC-MS) method is described for the analysis of prostaglandins (PGs) E1 and E2, which have several physiological actions at the trace level. HPLC separation was carried out on a reversed-phase column by using 50mM ammonium acetate (pH 4.5)-acetonitrile (7:3, v/v) as the mobile phase at a flow rate of 1.0ml/min. In MS detection, the vaporizer temperature was set at 220°C and the ion-source block temperature at 264°C. The mass spectra obtained from PGs typically exhibited the [M+NH4]+ ion (5 to 30% relative intensity) and several fragment ions due to sequential losses of water from both the [M+H]+ and [M+NH4]+ ions. PGE1 (46.9ppb) and PGE2 (1.9ppb) in the colostrum of dairy cattle were identified and quantitated. The PGE1 concentration in the colostrum and mature milk of dairy cattle showed a similar pattern to that in humans.