快速检测水样中甲烷含量的气相色谱法

A Rapid Gas Chromatography Method for Determination of Methane in Water Sample

该研究基于亨利定律,探讨了测定水样中甲烷含量的顶空气相色谱方法。应用SE-30非极性毛细管色谱柱,在优化后的顶空分析条件下,测定水样中甲烷组分浓度。结果显示,此方法绘制的标准曲线呈一次线性相关,相关度达99.954 6%。该方法的线性范围为0.013 19~1.978 4 mg/L,方法检出限为0.000 19 mg/L,最低检出浓度为0.001 57 mg/L,空白加标回收率为98.04%~99.82%;RSD为0.59%。以上指标分析结果均在方法学精度要求允许范围。表明该方法能实现水样中甲烷组分浓度的定量分析,分析时间仅为15 min,操作简便、精度高。

In order to determinate methane in water sample rapidly,this study proposes a gas chromatography method based on Henry's law.Methane in water sample is detected by FID through SE-30 non-polar capillary column in the optimized con- ditions of headspace analysis.The results show that the standard curve has a linear correlation,with correlation degree as 99.9546%.The indexes used to analyze the precision of the method include the linear range,the method detection limit,the minimum detection concentration,the recovery rate and RSD,which is 0.013 19-1.9784 mg/L,0.00019mg/L,0.00157mg/ L,98.04%-99.82%,0.59%respectively.It only takes 15 min to analyze a water sample,and this method is efficiency and simple,which is suitable for qualitative and quantitative analysis of methane in water sample.