罗丹明123荧光法测定阴离子表面活性剂

Determination of anionic surfactants in water using fluorimetric method with rhodamine123

研究了罗丹明123（RDM123）与阴离子表面活性剂（AS）的荧光反应,建立了荧光光度法测定环境水中阴离子表面活性剂。在稀H2SO4溶液中,罗丹明123与阴离子表面活性剂形成黄色荧光缔合物,激发波长为500 nm,发射波长为538 nm。通过含时密度泛函计算结果得：罗丹明123化合物激发波长主要是π→π＊电子跃迁产生。阴离子表面活性剂十二烷基苯磺酸钠（DBOSO3Na）、十二烷基硫酸钠（DSO4Na）浓度分别在0-56和0-115μg/m L范围与ΔF呈良好的线性关系,检出限分别为0.0576和0.0843μg/m L,方法用于环境水中阴离子表面活性剂的测定。

Rhodamine 123（ RDM123） is shown to possess photometric reaction to anionic surfactants（ AS）.Based on this property,we report a fluorimetric method to determine AS in natural water. In a diluted H2SO4 acidic solution,RDM123 reacts with AS to form a yellow fluorescent complex with an excitation wavelength of500 nm and an emission wavelength of 538 nm. Natural bond orbital（ NBO） analysis was performed,and the results revealed that the bond interaction type to be electrostatic between the RDM123 cation and the DSO4 anion. Time-dependent density functional theory（ TD-DFT） calculation indicates that the excitation wavelength of RDM 123 is produced by a complex π → π＊transition. Fluorescence intensity and the concentrations of two anionic surfactants,DBOSO3 Na and DSO4 Na are found to be linear in the range of 0 - 56 μg / m L with a detection limit of 0. 0576 μg / m L and 0 - 115 μg / m L with a detection limit of 0. 0843 μg / m L,respectively.Based on these findings,the proposed fluorimetric method for determining AS in natural water demonstrates efficacy.