A highly selective and sensitive liquid chromatography coupled with atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI-MS-MS) was developed and validated for the quantitation and pharmacokinetic study of carbazochrome sodium sulfonate in human plasma. Protein precipitation with 14% perchloric acid solution was selected for sample preparation, and amiloride hydrochloride was employed as an internal standard. The analytes were separated on a Hypersil ODS-2 column by a multiple-step linear gradient elution with a mobile phase consisting of 0.2% formic acid solution and methanol pumped at a flow rate of 1.0 mL/min. The determination was optimized and carried out with positive atmospheric pressure chemical ionization by selective reaction monitoring of the ion of m/z 148, the protonated thermodegraded fragment of the free acidic form of carbazochrome sodium sulfonate selected as the parent, and the ion of m/z 107 as the optimum collision induced dissociation (CID) product. The method was fully validated over a concentration range of 0.5-50 ng/mL, with the lower limit of quantitation of 0.5 ng/mL. The application of the LC-MS-MS method was demonstrated for the specific and quantitative analysis of carbazochrome sodium sulfonate in human plasma from a pharmacokinetic study in 24 healthy male Chinese volunteers after a single oral administration of 90 mg carbazochrome sodium sulfonate capsules.
2010 John Wiley & Sons, Ltd.