RÉSUMÉ
OBJECTIVE: To establish a high-performance capillary electrophoresis (CE) method for determinating gallic acid in commercial Quanshen pieces of two different colors, amaranth and brownish red. METHODS: CE-UV method was used in the following condition: BGE 20 mmol·L-1 sodium borate solution, voltage 20 kV, detection wavelength 290 nm, sample injection 10 s at 5 kPa, capillary temperature room temperature. RESULTS: A quantitative method was successfully developed to determine gallic acid in Quanshen pieces within 6 min. The contents of gallic acid in 7 batches of amaranth colored Quanshen pieces were 2.70% (Hubei province), 12.08% and 7.79% (Shandong province), 2.01%, 5.78%, 6.97%, and 4.22% (Hebei province), respectively. The contents of gallic acid in brownish red colored Quanshen pieces were 1.35% (Hubei province), 1.81% and 3.42% (Shandong province), 1.87%, 3.42%, 0.44%, and 1.52% (Hebei province), respectively. CONCLUSION: The method is rapid, economical and simple and can provide a powerful quality control measure for Quanshen pieces. The contents of gallic acid in the amaranth colored Quanshen pieces are higher than those in the brownish red colored pieces.