三种分光光度法测定水中甲醛的对比分析与方法评价

Comparative analysis and evaluation of three spectrophotometric methods for determination of formaldehyde in water

对现行实施的测定水中甲醛的三种分光光度标准分析方法,进行了比对分析试验;并从方法学的角度进行方法评价。测定水中甲醛的标准分析方法,主要有《4-氨基-3-联氨-5-巯基-1,2,4-三氮杂茂(AHMT)分光光度法》、《乙酰丙酮分光光度法》和《变色酸分光光度法》。对这几种分析方法,在实际分析测定的基础上,分别从方法的校准曲线、试剂空白影响、方法的灵敏度、有效测定范围等方面进行比对分析和评价。结果表明,在上述几种分析方法中,AHMT分光光度法的灵敏度最高,分别比变色酸光度法和乙酰丙酮光度法高1倍和4倍;同时方法的选择性好,可使大量醛类共存下不干扰测定,是现行标准分析方法中的优选分析方法。

The comparative experiments on the three currently applied standard spectrophotometric methods for determination of formaldehyde in water have been performed,and an evaluation has also been conducted from the perspective of methodology.4-Amino-3-hydrazino-5-mercapto-1,2,4triazole(AHMT)spectrophotometry,acetylacetone spectrophotometry and chronotropic acid spectrophotometry are the three major standard methods for determination of formaldehyde in water.To compare the effect of these methods,based on practical assay determination,related analysis and evaluation have been carried out in terms of calibration curve,reagent blank influence,sensitivity,detection limit,etc.According to the experimental results,among the methods above,the sensitivity of AHMT spectrophotometry is the highest,which is 1 time and 4 times of acetylacetone spectrophotometry and chronotropic acid spectrophotometry,respectively.In addition,the selectivity of AHMT spectrophotometry is the best,can make a large amount of aldehydes coexist without interfering with the determination.Therefore,AHMT spectrophotometry is an optimal analytic method among currently applied standard methods.