[Determination of ursolic acid in herba of Verbena officinalis by HPLC].Zhongguo Zhong Yao Za Zhi. 2002 Dec; 27(12):916-8.ZZ
To establish a HPLC method for determination of ursolic acid in dried aerial part of Verbena officinalis.
The column used was a Kromasil C18 (4.6 mm x 250 mm) packed with a 5 microns stationary phase. The mobile phase consisted of methanol-sodium phosphate buffer [monobasic sodium phosphate (MW = 119.98) 1.7997 g and phosphoric acid (85%) 1.02 mL, combined and brought the total volume of 1,000 mL with water] (89:11); the mobile phase was maintained at a flow-rate of 0.8 mL per minute; the column was maintained at 40 degrees C; the DAD detector was set at 210 nm.
The liner range was 0.251-10.04 micrograms (r = 1.0000). An average recovery of 98.1% (n = 6) was obtained with a RSD of 1.0%.
The method is simple, accurate and suitable for the qualify control.