品红亚硫酸钠试剂在快速检测甲醛中的应用

Application of Fuchsin Sodium Sulfite in Rapid Detection of Formaldehyde

利用品红亚硫酸钠检测甲醛时,该试剂的配制和使用条件对试剂本身的稳定性及检测的灵敏度均有影响。试验对试剂的适宜配制和使用条件进行了筛选研究,并通过测定甲醛标样与试剂反应的开始变色时间、初始颜色、初始吸光度、稳定时间、稳定颜色和稳定吸光度,建立了比色色列。试验结果表明:在配制试剂过程中,溶解品红的适宜水温为80℃,在100mL溶液中添加2mL9.8%硫酸有利于提高试剂的稳定性;在检测样品中甲醛残留过程中,品红亚硫酸钠试剂的使用温度应低于55℃,反应环境适宜pH为1.5～6.4。检测过程中主要干扰物为乙醛,在2mL待测液中加入1滴0.98%硫酸处理可排除该干扰。不同浓度甲醛标样与品红亚硫酸钠显色反应呈现不同颜色,在最适反应条件下,根据测定结果做出色列表,将试样反应显色与色列对比可半定量检测出试样中甲醛的含量。

It is noted that the preparation and utilization condition for fuchsin-sodium sulfite can influence the stability of the reagent and the sensitivity of rapid detection for formaldehyde. The optimum conditions for preparation and utilization of fuchsinsodium sulfite were studied, and a colorimetry table was established through measuring reaction parameters between formaldehyde standard solution and fuchsin-sodium sulfite. The results showed that the optimum water temperature for dissolving fuchsin was 80℃, and adding 2mL 98% sulphuric acid for every 100mL solution could increase the stability of the reagent when fuchsinsodium sulfite solution was prepared. The optimum conditions for utilizing this reagent to detect rapidly formaldehyde residue were as follows： temperature of reaction lower than 55℃ ,pH value of the reaction environment 1.5-6.4. The colorimetry table could be used to evaluate rapidly formaldehyde residue in samples by comparing the color of the reaction product with that on the colorimetry table.