Quantitative measurement of prostaglandins E2 and E2 by selected ion monitoring

A method for the simultaneous quantitative analysis of prostaglandin E2 (PGE2) and PGE3 is described. The PG were analyzed by selected ion monitoring as the methyl ester-TMS ether derivatives of PGB2 and PGB3, respectively. The internal standard for the quantification of both species was [3,3,4,4-2H4]PGE2. A linear response over the range 0.6--50 ng (1.7--143 pmoles) was demonstrated for PGE3. The chromatographic conditions used (2% SP-2330 column) afforded nearly baseline separation of the prostaglandins. New standard curves for PGE3 must be developed each time the ion source parameters are changed. In a typical calibration run, the instrumental precision, expressed as coefficient of variation, ranged from 1.1 to 7.2% for PGE2 (3 to 100 ng injected) and from 1.6 to 11.1% for PGE3 (1.5--50 ng injected). The method was applied to the PG analysis of rat renomedullary tissues. The recovery of synthetic PGE2 added to medullary homogenates was 100.5 +/- 1.7% (mean +/- SEM, n = 9), and the recovery of PGE3 was 91.3 +/- 1.4% (n = 9).