二硝基苯肼柱前衍生-HPLC法测定水中微量甲醛和乙醛

Simultaneous Determination of Trace Formaldehyde and Acetaldehyde in Water by Precolumn Derivation High-performance Liquid Chromatography

目的探讨二硝基苯朋(DNPH)衍生化高效液相色谱(HPTC)法测定水中微量甲醛和乙醛的方法。方法在60℃的水浴中,水样中的甲醛和乙醛经DNPH衍生化20 min,用环己烷提取,用高效液相色谱仪测定。结果甲醛、乙醛在0～8.0μg/mL浓度范围内,标准曲线线性关系良好,甲醛和乙醛的相关系数r分别为0.9997和0.9996;甲醛和乙醛的相对标准偏差分别为0.5%～2.4%和1.1%～3.2%;加标回收率分别为97.6%～99.3%和98.4%～101.7%;方法最低检出浓度分别为0.002和0.005 mg/L。甲醛检测结果与国标方法比较无显著性差异(P大于0.05)。结论本方法不但可同时检测水中微量的甲醛和乙醛,具有灵敏度高、选择性好、精密度和准确度好等优点,而且简便、快捷,适合大批量样品分析。

Objectives To develop a method for the determination of trace formaldehyde and acetaldehyde in water by precolumn derivation high-performance liquid chromatography. Methods Samples were treated by 2,4 dinitrophenylhydrazine in 60℃ water bath for derivation for 20 rain, and then were extracted with cyclohexane ; the contents of formaldehyde and acetaldehyde were finally analyzed by high-performance liquid chromatography quantitatively. Results The linear ranges for the determination of formaldehyde and acetaldehyde were 0- 8.0 p,g/mL （ r = 0. 9997 ） and 0 - 8.0 μg/mL （ r = 0. 9996 ） , respectively. The relative standard derivations for formaldehyde and acetaldehyde were 0.5% - 2.4% and 1.1% - 3.2% , respectively. The recoveries were 97.6% -99. 3% and 98.4% - 101.7% respectively. Conclusions The method has the advantages of simplicity, repeatability and sensitivity; it can be used for simultaneous analysis of formaldehyde and acetaldehyde in water.