Determination of ethanol content in fruits by gas chromatography

The ethanol content in fruits( cherry,strawberry,pear,jujube) were determined by gas chromatography( GC) equipped with DB-WAX( 60 m × 0.25 mm × 0.25 μm) and hydrogen flame ionization detector.Results showed that the inlet and FID detector temperature were 230 ℃ and 300 ℃,respectively.The column temperature program was initial 40 ℃( held for 11 min),with the increase rate of 20 ℃ / min to 220 ℃( held for 13 min). The carrier gas was nitrogen,and the flow rate was 2 m L / min. The calibration curve showed good linearity when ethanol concentration was in the range of 0.25~100 μg / m L with correlation coefficient of 0.99998,and the detection limit was1.25 mg / kg.The method was stable,repeatable and reproducible with RSD less than 2%. The average recoveries ranged from 90.88% to 108.80%( RSD = 0.18% ~ 7.18%,n = 6). The method was simple,accurate,and met the requirements of methodology,which may be used for the determination of the ethanol in fruits.