双波长叠加紫外光度法测定SDBS

Determination of SDBS with Nile Blue Sulphate by Dual-wavelength Overlapping UV-Spectrophotometric

研究了硫酸耐尔蓝与十二烷基苯磺酸钠（SDBS）的反应，建立测定SDBS的双波长叠加紫外光度法。在pH=5．02缓冲溶液中，硫酸耐尔蓝与SDBS形成离子缔合物，在紫外区有正、负吸收峰，最大正吸收波长位于304nm，最大负吸收波长位于280nm，摩尔吸光系数分别为ε280为2．5×10^4L·mol^-1·cm^-1 ε304为2．2×10^4L·mol^-1·cm^-1，当用双波长叠加法时，ε280＋304为4．7×10^4L·mol^-1·cm^-1，线性范围均为0．5—4mg／L。研究了反应的适宜条件，用于环境水中SDBS的测定，回收率在98．9％～103．2％。

A new UV - spectrophotometry method for the determination of sodium dodecylbenzene sulfonate （SDBS） were studied, based on the reaction of SDBS with Nile blue sulphate. In pH = 5. 02 buffer solution, Nile blue sulphate and SDBS could form ion association complexes with an obvious positive absorption peak and a negative absorption peak. The maximum positive absorption wavelength was found at 304 nm and maximum negative absorption wavelength was found at 280 nm. Their apparent molar absorptivity of ε304 was 2.5×10^4L·mol^-1·cm^-1, ε280 was 2.2×10^4L·mol^-1·cm^-1, When the dual - wavelengths overlapping absorption spectrometry were used to determine SDBS, the apparent molar absorptivity of ε304 ＋280 was 4.7×10^4L·mol^-1·cm^-1. The linear ranges of SDBS were from o. 5 to 4 mg/L. The optimum reaction conditions were studied. The method was applied to determine the environmental waters with satisfactory results. The recoveries were 98. 9% - 103. 2% .