Gas chromatographic-mass spectrometric determination of urinary 1-aminocyclopropanecarboxylic acid in mice using a deuterated internal standard.

A gas chromatographic-mass spectrometric method is described for the determination of 1-aminocyclopropanecarboxylic acid in mouse urine using the 2,2,3,3-[2H4] isotopolog as an internal standard. Samples (0.1 ml) were extracted using an exchange resin, then derivatized with pentafluoropropanol and pentafluoropropionic anhydride at 100 degrees C for 25 min. Gas chromatography was performed on a (5% phenyl)methylpolysiloxane column and detection was by selected-ion monitoring of M-CO2CH2CF2CF3 fragment ions. The method provided high response linearity (mean r = 0.999) and precision (< 5% coefficient of variation). After orally dosing mice with 1-aminocyclopropanecarboxylic acid (300 mg/kg), 46 and 10% of the dose was excreted unchanged in the 0-24 h and 24-48 h urines, respectively.