几种聚氧乙烯型非离子表面活性剂的分光光度法测定及其应用

介绍了几种聚氧乙烯型非离子表面活性剂的KI-I2分光光度法测定,讨论不同实验条件对测定的影响。结果表明,以碘-碘化钾溶液为显色剂的KI-I2分光光度法测定波长为500nm,显色时间为120min,Brij35,Brij30,TritonX-100和Tween-80工作曲线相关系数在0.9971~0.9995之间;检测范围分别为0.2~25mol/L、0.4~25mol/L、1.5~50mol/L和0.5~50mg/L;操作简单,酸稳定性好,大部分盐类、非离子和阴阳表面活性剂、土壤腐植酸、土壤浸提液对测定的干扰小;易水解的Al3 和Fe3 对测定有较大的干扰,但加酸后即可消除。方法直接用于测定聚氧乙烯型非离子表面活性剂在土壤上的吸附等温线获得了满意的效果。

Spectrophotometric Determination of Some Polyoxyethylene Nonionic Surfactants and Its Application

The method KI-I_2 spectrophotometry used in determing polyoxyethylene nonionic sfrfactants had been studied. In addition, the effect of different experiment conditions on the determination of nonionic sfrfactants was discussed. The results show that the wave length for determination of nonionic surfactant 500 nm and the reactive time with KI-I_2 developer was 120 min respectively, The work curves of Brij35, Brij30, Triton X-100 and Tween-80 were highly linear (correlation coefficient was 0.9971-0.9995) and their linear ranges were 0.2-25 mg/L, 0.4-25 mg/L, 1.5-50 mg/L, respectively. Furthermore, the spectrophotometric method was stable for acid condition and free from interference by most of metal ions, nonionic or anion or cationic surfactants and soil extractions. Al 3 and Fe 3 tend to hydrolysis and seriously interfere with cletermination of nonionic surfactents. How ener, such a inter ference coluld be eliminated by adjusting solution to acidic environment. The determination method was suceessfully applied to the determination of adsorption is otherm of four polyoxyethylene nonionic suerfactants on soils tested.