Development of a LC-ESI/MS/MS assay for the quantification of vanillin using a simple off-line dansyl chloride derivatization reaction to enhance signal intensity.

Vanillin is responsible for producing the familiar smell of vanilla. Vanillin has many similarities with other flavor phenolic compounds and could potentially show similar pharmacological activity. A previously published analytical method was adapted, developed and tested. Vanillin was extracted from rat plasma using protein precipitation with acetone. Prior to LC-ESI/MS/MS analysis, an aliquot of the supernatant was used to proceed to the derivatization of vanillin and the internal standard with dansyl chloride to enhance signal intensity in positive electrospray mode. The chromatography was performed on a 100 x 2.1 mm C8 column and an isocratic mobile phase composed of 75:25 acetonitrile:0.5% formic acid in water with a flow rate fixed at 500 microL/min. A linear (weighted 1/concentration) relationship was used to perform the calibration over an analytical range of 10-10,000 ng/mL. The intra-batch precision and accuracy at the limit of quantitation (10 ng/mL), medium (500 ng/mL) and high (10,000 ng/mL) concentrations were 10.7, 7.0 and 7.2% and 103.5, 108.0 and 100.1%, respectively. The observed recovery was greater than 87% and no significant ionization suppression or matrix effect was observed. This LC-ESI/MS/MS method for the determination of vanillin in rat plasma provided results within generally accepted criteria used for bioanalytical assay. Copyright 2007 John Wiley & Sons, Ltd.