[TLC scanning determination of baicalin content in niuhuang qingxin pills]

Baicalin in the samples was extracted with ultrasonic wave, the extract was spotted on thin-layer plates of gel GF254 and developed with the mobile phase consisting of toluene-ethylacetate-formic acid (2:3:2.2). Determinations were carried out with Shimadzu CS-930 TLC scanner with lambda s = 280 nm and lambda R = 207 nm. The linear range was 0.46-4.6 micrograms/ml. The average recovery of baicalin from the samples was 98.35%, RSD = 2.82%.