RESUMEN
OBJECTIVE: To develop an HPCE method of tetramethylpyrazine hydrochloride in rat plasma using pyramide as the internal standard. METHODS: The separation was performed on a fused-silica uncoated capillary with an inner diameter (ID) of 75 μm, an effective length of 50 cm and a total length of 60 cm. The optimum HPCE conditions were as follows: 100 mmol·L-1 SDS-30 mmol·L-1 sodium tetraborate solution (40:60) was used as the background electrolyt, the samples were injected at the anodic end at 0.5 psi for 6 s, separation voltage was 20 kV at positive power, capillary temperature was 20°C, and detection wavelength was 295 nm. RESULTS: The linear range was 1.12-286.72 mg·L-1(r=0.9996), and the inter-day and intra-day precisions expressed as RSDs were less than 4.21% and 4.74%, respectively. The average recoveries were 91.22%-97.48%, and the limit of detection was 0.16 mg·L-1. CONCLUSION: This method is rapid and accurate to quantify tetramethylpyrazine hydrochloride in rat plasma.