色谱柱内衍生反应测定甲醛的含量

将化学反应和色谱分离过程相结合,在柱内进行衍生反应,通过向流动相中加入新型衍生剂偏二甲肼,使待测组分甲醛在色谱柱内反应生成紫外检测器可检测的偏二甲腙。实现对不能直接用紫外法检测的甲醛的分析,研究表明此方法较经典的柱前衍生化法有简单、实用的优点。线性范围30~300mg/L,检出限量为5ng,相对标准偏差为0.29%(n=6),加标回收率为95.90%~102.5%

Determination of Formaldehyde by In-column Derivatization Reaction

Combined chemical reaction with chromatography separation process,in-column derivative reaction was carried out with a novel derivative reagent of unsymmetrical dimethyl hydrazine(UDMH) added to mobile phase which reacted with formaldehyde to form unsymmetrical dimethyl hydrazone.The later was then measured by ultraviolet detector to finally determine the content of formaldehyde which could not be directly analyzed.Results obtained in this paper proved that in-column derivatization was more simple and practical than classical pre-column derivatization.The calibration curve showed excellent linearity in the range of 30~300mg/L.The limit of detection was 5ng.The relative standard deviations was 0.29%(n=6) and the recovery was 95.90%~102.5%.