Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry for Simultaneous Analysis of 22 Analytes of Oncheong-Eum, a Traditional Korean Herbal Formula

Abstract

Oncheong-eum (OCE) is a traditional Korean herbal formula comprising eight medicinal herbs for treating skin disorders, including eczema and skin rashes. Here, we sought to simultaneously analyze 22 analytes of OCE using ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS). All analytes were separated on a Waters Acquity UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) maintained at 45 °C by gradient elution with a mobile phase of 0.1% (v/v) aqueous formic acid–acetonitrile. By applying a multiple reaction monitoring method, we rapidly determined the various analytes simultaneously. The coefficient of determination of the regression equation prepared in the tested concentration range of each authentic reference standard was ≥0.9950 and showed good linearity. The accuracy ranged from 84.23% to 115.47%, and the relative standard deviation values for intra- and interday precisions ranged from 0.84% to 9.57%, respectively. Analysis of OCE samples using this method showed that they contained up to 27.10 mg/g of active ingredients. The method can provide data to improve the consistency and, thus, the future quality of OCE preparations and other traditional herbal formulas.