A PGE2-derivative for quantitative gas chromatographic mass spectrometric measurement in the selected ion monitoring mode

Abstract

The quantification of prostaglandin PGE2 by gas chromatography mass spectrometry in the form of an easily prepared derivative is described. After extraction and purification of biological samples the compound was derivatized in two steps to 9-enol-PGE2- methylester - trimethylsilylether , 9-enol-PGE2-Me- TMS3 . The molecular ion at m/z 582 with 40% relative abundance and the fragment ion at m/z 492 with 100% relative abundance permit a specific and sensitive evaluation in the selected ion monitoring mode. The high masses selected lie above the biological background. The calibration curve produced by adding known amounts (10-200 ng) of PGE2 to blank human urine and with (2H4)-deuterated PGE2 as internal standard gave a linear correlation. The separation from biological impurities was obtained on a 50 m glass capillary column and resulted in sharp and symmetrical peaks.

Derivatization in Mass Spectrometry—6. Formation of Mixed Derivatives of Polyfunctional Compounds

“…The [M -Me 3 SiOH] +• ions and tetradeuterio analogs as internal standards were involved in the measurement. 94,95 Quantitative analysis of some similar prostaglandins can be accomplished by GC/EI-MS in a SIM mode by applying other fragment ions. For example, ions [M -C 5 H 11 -Me 3 SiOH] + (loss of pentyl radical as shown in the above structure) appeared to be more suitable for simultaneous determination of prostaglandins F 2α , E 1α , E 2α and 19-hydroxy-F 2α and -E 2α in the semen of fertile men.…”