静态顶空与顶空固相微萃取-气相色谱法测定食用油中正己醛含量比较
Comparison of determination of hexanal in edible oils by static headspace and headspace- SPME method
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摘要: 分别采用静态顶空(SHS)及顶空固相微萃取技术(HS-SPME)与气相色谱联用来分析食用油中的正己醛的含量。SHS中选用的提取温度和时间为130℃和15 min,HS-SPME中用85μm Carboxen/PDMS萃取头,在130℃萃取15 min。通过同一浓度的标准溶液来比较两种方法的线性、精密度、准确度和检出限。结果表明:两种方法在0.001.00μg/g范围内都具有良好的线性,标准曲线相关系数都在0.999以上,SHS法的结果稳定,重现性好,加样回收率为98.63%100.02%,RSD为0.74%2.92%,结果优于HS-SPME法。且SHS法的检出限(5.3 ng/g)也低于HS-SPME法(31.5 ng/g)。采用F检验和t检验分析统计两种方法的测定结果无显著性差异,综合比较来看,采用SHS法测定更合理准确,节约成本,在实验室分析油脂中正己醛含量的测定中可优先考虑SHS前处理法。Abstract: Two methods for determination of hexanal in edible oils were analyzed by Static Headspace( SHS) and Headspace- Solid Phase Microextraction( HS- SPME) respectively.The hexanal were quantitatively analyzed by the gas chromatography( GC).HS- SPME and SHS were compared in terms of linear response,precision,accuracy,and detection limit.The results showed that both two methods had good linear correlation between 0.00 and 1.0 μg / g,the coefficient were above 0.999.At the same time,the result of SHS had good stability,reproducibility and sample recovery with 98.63% ~100.02% and RSD was 0.74% ~2.92%,which was better than that of the HS- SPME.And the detection limit of SHS( 5.3 ng / g) was lower than SPME( 31.5 ng / g). There were no significant difference between the two methods,However,the SHS was more reliable and accurate,it could be considered as the optimum method for the analysis the contents of hexanal in edible oils when applied in the lab.