浊点萃取预富集胶束增稳室温燐光法测定吲哚-3-丁酸

Determination of Indole-3-butyric Acid by Micelle-stabilized Room-temperature Phosphorimetry with Cloud Point Extraction for Preconcentration

提出了以非离子表面活性剂Triton X-100为萃取剂的浊点萃取预富集吲哚-3-丁酸，进而用胶束增稳室温烧光法对其进行测定的新方法。通过加入氯化钠降低表面活性剂溶液的浊点，使浊点萃取得以在15℃的环境温度下顺利完成。在基于浊点萃取而进行的相分离之后，富表面活性剂相以水适当稀释，然后用胶束增稳室温烯光法测定其中被富集的吲哚-3-丁酸。在最佳条件下，工作曲线的线性范围为1．0×10^-8 2．4×10^-7 mol／L，检出限（信噪比为3）为7．4×10^-9mol／L。方法用于自来水、江水、池塘水和土壤等强化样品中吲哚-3-丁酸的测定，回收率95％～105％，相对标准偏差2．5％～4．8％。

A new method was developed for the determination of trace indole-3-butyric acid（IBA） by mieelle-stabilized room-temperature phosphorimetry（MS-RTP）. The sample was preeoneentrated with the cloud point extraction（CPE） method using non-ionic surfaetant Triton X-100 as the extraetant. The CPE process could be facilitated at an ambient temperature of 15 ℃ by adding an appropriate amount of sodium chloride to lower the cloud point of the surfactant solution. After phase separation, the preconeentrated IBA in the rich surfaetant phase was determined by MS-RTP. Under optimized conditions, the linearity of the calibration curve for IBA was in the range of 1.0 × 10^-8 -2.4 × 10^-7 mol/L with a detection limit of 7.4 × 10^-9 mol/L（S/N = 3）. The proposed method was applied to the analysis of IBA added to tap water, river water, pond water and soil samples. The recoveries were in the range of 95% - 105% with relative standard deviations of 2.5% -4.8% .