工业甲醛溶液中甲醇气相色谱法检测条件的优化

Optimization of detection conditions for methanol in industrial formaldehyde solution by gas chromatography

采用有机相乙腈溶解甲醛进行气相色谱法检测甲醇含量,以正丁醇作为内标物,外标法进行定量分析。与水相的国家标准方法进行结果对照,该方法检出限为,2种浓度加标水平下,样品的加标回收率在96.73%~98.23%之间。该方法灵敏度高,稳定性好,有效地避免了甲醛水溶液低温浑浊现象,正丁醇比乙醇保留时间长,能够更好地与目标组分甲醇进行区分,可替代现行有效标准方法。

The methanol content was detected by gas chromatography using organic phase acetonitrile to dissolve formaldehyde,and n-butanol was used as the internal standard,and the external standard method was used for quantitative analysis. Compared with the national standard method for water phase,the detection limit of this method is that the recovery rate of the samples is between 96.73 and 98.23% under the two concentration levels. The method has high sensitivity and good stability,and can effectively avoid the low-temperature turbidity of the formaldehyde solution. The retention time of n-butanol is longer than that of ethanol,which can better distinguish it from the target component methanol,and can replace the current effective standard method.