Quantification and discovery of quality control chemical markers for Shouhui Tongbian capsules by UPLC-MS/MS

Guided by the principles of Analytical Quality by Design (AQbD), a highly selective and sensitive LC-MS/MS method was established for the simultaneous quantification of 15 compounds in Shouhui Tongbian capsules, enabling their effective quality control. The separation was carried out on a BEH C18 column (1.7 μm, 2.1 × 100 mm) with a mobile phase comprising 0.1% formic acid in 3 mM ammonium acetate aqueous solution and methanol (60 : 40, v/v) at a flow rate of 0.30 mL min^-1. The method exhibited good linearity within a certain concentration range (R² > 0.9906) depending on the compound; the precision ranged from 0.6% to 14.7% and accuracy was within 11.2%. Among the 15 detected compounds, aloin had the highest content in the Shouhui Tongbian capsules, reaching 227.3780 mg g^-1, followed by betaine and L-hydroxyproline, with concentrations of 1.3204 mg g^-1 and 1.2929 mg g^-1, respectively. This method simultaneously detected the content of 15 compounds in five batches of Shouhui Tongbian capsules.