HPLC-fluorescence method for determination of tramadol hydrochloride in human plasma

OBJECTIVE To develop an HPLC fluorescence method for determination tramadol hydrochloride in human plasma.METHODSThe method involved a single liquid-liquid extraction procedure and aspecific determination with fluorescence detector,in witch fluconazol was used as internal standard.HPLC instrument was used with the column C18(Diamonsil,250 mm×4.6 mm,5 μm),the mobile phase was composed of phosphate buffer solution(0.04 mol·L-1,pH 3.5)-acetonitrile(77∶23).The fluorimetric excitation and emission wavelength were set at 275 nm and 302 nm,respectively.RESULTSLinear range was 5-1 000 μg·L-1.The lower limit of quantitation was 1.0 μg·L-1.The within-day and between-day precision of variation was less than 7.7%.The average extraction recoveries for tramadol were(85.2±4.3)%,(80.6±3.5)% and(83.6±3.6)%,respectively.CONCLUSIONThe method is reproducible,sensitive,convenient and rapid.It is applicable to the determination of the concentration of tramadol in human plasma.