水果中乙醇含量的气相色谱法测定
Determination of ethanol content in fruits by gas chromatography
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摘要: 以樱桃、草莓、梨、枣四种水果为试材,采用DB-WAX(60 m×0.25 mm×0.25μm)毛细管色谱柱和氢火焰离子化检测器建立了气相色谱法测定水果中乙醇含量的方法。结果表明,在进样口温度230℃,FID检测器温度300℃,程序升温40℃(保持11 min),以20℃/min升至220℃(保持13 min),以氮气为载气,柱流量2 m L/min的条件下,乙醇有良好的分离效果。乙醇含量在0.25100μg/m L范围内,具有良好的线性关系(R2=0.99998),最低检出浓度为1.25 mg/kg。该方法稳定性、重复性和重现性良好,RSD均小于2%。在四种水果低中高三个添加水平下,平均回收率在90.88%108.80%之间(RSD=0.18%7.18%,n=6)。该方法操作简单,准确可靠,符合方法学要求,可用于水果中乙醇含量的检测。Abstract: 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.