柱前衍生高效液相色谱法同时测定水性涂料中6种醛类化合物

摘要

建立了柱前衍生高效液相色谱同时测定水性涂料中甲醛、乙醛、丙醛、苯甲醛、正戊醛和对甲基苯甲醛等6种醛类化合物的方法。样品经水超声提取后，与2，4-二硝基苯肼乙腈溶液在酸性条件下衍生，再经0.45μm 针式过滤器过滤后进样分析。系统考察了酸度调节剂、pH 值、反应温度、时间等因素对衍生反应的影响，优化的反应条件为：以稀释后的盐酸溶液作为酸度调节剂，缓冲溶液 pH =3，反应温度为60℃，反应时间为30 min。在此条件下，于0.08~2.0 mg / L 浓度范围内，6种醛类化合物呈良好的线性关系；检出限为0.05~2.50 mg / kg；在2.0、4.0、6.0 mg / kg 3个水平下的加标回收率为87.0％~112.8％；RSD 为1.12％~9.54％。结果表明，本方法具有较宽的线性范围，良好的精密度和准确度，适用于水性涂料中6种醛类化合物的同时测定。%A high performance liquid chromatography method with pre-column derivatization was developed for the simultaneous determination of formaldehyde,acetaldehyde,propionalde-hyde,benzaldehyde,n-valeraldehyde and p-tolualdehyde in water-based coatings. After ultra-sonic extraction with water, the samples were derivatized with 2,4-dinitrophenylhydrazine (2,4-DNPH)in acetonitrile under acidic condition,then filtrated by 0. 45 μm organic syringe filters for the determination. Systematic investigation was carried out on the dependence of the derivatization conditions such as the acidity regulator,pH value,reaction temperature,reaction time and other factors. The optimized conditions were as follows:the dilute hydrochloric acid solution as acidity regulator,the pH of the buffer solution of 3,the reaction temperature of 60℃ ,and the reaction time of 30 min. Under the conditions,a linear relation was achieved in the range of 0. 08-2. 0 mg / L for the peak area to concentration of the six aldehydes. The detection limits were 0. 05-2. 50 mg / kg. The recoveries of standard addition at the spiked levels of 2. 0, 4. 0,6. 0 mg / kg were 87. 0% - 112. 8% with the relative standard deviations( RSDs,n = 6)of 1. 12% -9. 54% . The results showed that this method has a wide linear range,good precision and accuracy,and it is suitable for the simultaneous determination of the six aldehydes in water-based coatings.