Capillary Column Gas Chromatographic Determination of Residual Solvents in Daidzein

A method of capillary column gas chromatography for the determination of residual solvents in daidzein was reported in this paper. The sample (0.5 g) was dissolved in DMSO containing n-butanol as internal standard and made up to volume of 5 mL. Under the optimized conditions,using a gas chromatograph equipped with DB-17 quartz capillary column (0.54 mm×30 m,1.0 μm) as separation column and FID as detector,the residual solvents,ethanol and DMF,in daidzein were determined. Detection limits were 9.6 pg for ethanol and 5.7 ng for DMF. Linear regression equations were Y=0.046 27+0.653 69 X with r=0.998 2 for ethanol,and Y=0.025 31 X+0.356 54 X with r=0.993 4 for DMF. Linearity was ranged in 50.4-718.9 g·L-1 for ethanol and 9.8-137.2 g·L-1 for DMF.