大豆磷脂中溶剂正己烷残留检测

Detection of residual hexane in soya lecithin by GC

溶剂残留是磷脂产品食品安全重要指标。鉴于国家标准指定的检测方法检测磷脂产品存在缺陷,该文建立适合磷脂产品的气相色谱测定大豆磷脂中残留溶剂正己烷含量的方法。通过以大豆油为溶剂与大豆磷脂以4∶1（大豆油∶大豆磷脂）的比例混合,保证磷脂样品具有较好流动性。使用毛细管色谱柱（30 m×250μm×0.25μm）,FID检测器,以氮气为载气,顶空进样,采用外标法计算残留溶剂的含量。磷脂正己烷溶剂残留在0-270 mg/kg线性范围中（即每个顶空瓶正己烷含量0-1.35 mg之间）线性关系良好（0.998 4）,加标回收率在95%-101%之间。该方法具有简单、快速、准确特点。

Residual solvent is an important food safety specification of soya lecithin. Because of the defect of the detection of national standard,the study developed a method of detecting the residual hexane in soya lecithin by GC. To make sure the flowability of soya lecithin,we mixed the soya lecithin with soya oil by ratio of 1 to 4. A capillary column（30 m×250μm×0.25μm）was adopted with nitrogen as carrier gas and soya oil as solvent by headspace sampling. The residual solvent was calculated according to the external standard method. There was good linear relationship（r=0.999 6） at the rang from 0~270 mg/kg. The average recoveries were from 95% to 101% with the relative standard deviation less than 5%. The method was simple,rapid and accurate.