Determination of 1-methoxy-2-propanol and its metabolite 1,2-propanediol in rat and mouse plasma by gas chromatography.

A method utilizing capillary GC and flame ionization detection was developed for the simultaneous determination of 1-methoxy-2-propanol (propylene glycol monomethyl ether; PGME) and its metabolite 1,2-propanediol (propylene glycol; PG) in rat and mouse plasma. The calibration graphs for rat and mouse plasma were linear with correlation coefficients at > 0.997 over the range 2-700 micrograms/ml. The limit of quantification was ca. 2 micrograms/ml (2 ng on-column) for both compounds in plasma of each species. The ranges of the precision and accuracy for PGME were 2.8-8.8% and 3.2-13%, respectively, and for PG were 11-26% and 10-25%, respectively. The recovery of PGME from rat and mouse plasma was ca. 73% and for PG it was ca. 65 and 31% from rat and mouse plasma, respectively. The method was used to study the oral absorption and metabolism of PGME in mice. PGME was readily absorbed and metabolized to PG following oral gavage administration at 90 mg/kg. The maximum concentrations of PGME and PG in plasma were attained at 20 and 30 min following dosing, respectively.