The development of a simple, reliable method for determination of detergent micelle aggregation number that relies solely on measurement of steady-state fluorescence quenching is presented. The degree of steady-state fluorescence quenching of a micelle-solubilized fluorophore (pyrene) by a quencher that partitions greatly into the micelles (coumarin 153) is dependent on the micelle concentration, which can therefore be determined. The aggregation number is calculated as the micelle concentration/detergent monomer concentration (the total detergent concentration above the critical micelle concentration). For the determination to be accurate, the partition coefficient of the quencher into the micelle phase is determined and used to calculate the micellar concentration of quencher. Also, the quenching of pyrene by a coumarin 153 molecule within the same micelle must be complete, and this was confirmed by time-resolved fluorescence measurements. Aggregation numbers were determined for one cationic and several nonionic detergents and were found to be consistent with literature values. The approach presented is an improvement on a previous luminescence quenching technique (Turro, N.J., and A. Yekta. 1978. J. Am. Chem. Soc. 100:5951-5952) and can be used on cationic, anionic, and nonionic detergents with micelles ranging greatly in size and under varying conditions, such as detergent concentration, ionic strength, or temperature.
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机译：提出了一种简单，可靠的测定去污剂胶束聚集数的方法，该方法仅依赖于稳态荧光猝灭的测量。胶束溶解的荧光团（py）的稳态荧光猝灭程度取决于在胶束（香豆素153）中大量分配的猝灭剂，因此取决于胶束浓度。以胶束浓度/洗涤剂单体浓度（高于临界胶束浓度的总洗涤剂浓度）计算聚集数。为了确定准确，确定淬灭剂在胶束相中的分配系数，并用于计算淬灭剂的胶束浓度。同样，必须完成在同一胶束中香豆素153分子对pyr的淬灭，这已通过时间分辨荧光测量得到证实。测定一种阳离子和几种非离子型去污剂的聚集数，发现其与文献值一致。提出的方法是对先前的发光淬灭技术的改进（Turro，NJ和A. Yekta。1978. J. Am。Chem。Soc。100：5951-5952），可用于阳离子，阴离子和非离子洗涤剂中胶束的尺寸变化很大，并且在不同条件下（例如去污剂浓度，离子强度或温度）变化很大。
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