Simultaneous LC determination of spinosin, danshensu, and protocatechuic aldehyde in traditional Chinese Zaoren-an-shen capsules

A simple, sensitive, and accurate liquid-chromatographic method with UV detection has been developed for simultaneous determination of spinosin, danshensu, and protocatechuic aldehyde in traditional Chinese Zaoren-an-shen capsules. Chromatographic separation was achieved on a C₁₈ column. Vanillin was used as internal standard and the UV detection wavelength was 280 nm. Excellent linear behavior was observed over the concentration ranges investigated, with R values higher than 0.9997 for all the analytes. The limits of quantification for spinosin, danshensu, and protocatechuic aldehyde were 1.31, 0.74, and 0.27 μg mL^-1, respectively. This validated method can be used for routine quality control of Zaoren-an-shen capsules.