Determination of Seven Residual Solvents in Liuwei Dihuang Glycoside by Gas Chromatography Method / 中国药房

ABSTRACT

OBJECTIVE:To establish a method for the determination of 7 residual solvents(ethanol,n-hexane,benzene,tolu-ene,xylene,styrene,divinylbenzene)in Liuwei dihuang glycoside. METHODS:The column was DB-624 capillary column,carri-er gas was nitrogen,flow rate was 5.0 ml/min;detector was a hydrogen flame ionization detector with temperature of 250 ℃(pro-grammed temperature);equilibrium temperature was 80 ℃,sample loop temperature was 90 ℃,and transfer line temperature was 100 ℃;the equilibrium time of vial heating was 30 min,sample loop filling time was 0.05 min,injection time was 1.0 min;the carrier gas pressure was 95 kpa,and the vial pressure was 60 kpa. RESULTS:The linear range was 25-500 μg/ml for ethanol(r=0.998 7),0.025-10μg/ml for n-hexane(r=0.998 8),0.025-10μg/ml for benzene(r=0.999 9),0.1-40μg/ml for toluene(r=1.000 0),0.25-100 μg/ml for xylene(r=0.999 9),0.5-500 μg/ml for styrene(r=1.000 0) and 0.5-500 μg/ml for divinylbenzene (r=1.000 0);RSDs of precision,stability and reproducibility tests were lower than 4%;recoveries were 99.60%-102.70%(RSD=1.08%,n=9),90.70%-100.30%(RSD=4.51%,n=9),100.10%-109.80%(RSD=3.82%,n=9),99.50%-110.00%(RSD=4.40%,n=9),100.00%-109.10%(RSD=3.50%,n=9),93.40%-102.30%(RSD=3.73%,n=9) and 99.70%-101.70%(RSD=0.79%,n=9),respectively;the low limits of detection were 1.000,0.025,0.025,0.025,0.100,0.025,0.250 μg/ml respectively. CONCLUSIONS:The method is simple,stable and reproducible,and can be used for the determination of residual solvents(etha-nol,n-hexane,benzene,toluene,xylene,styrene,divinylbenzene)in Liuwei dihuang glycoside.