Kamiusuki T, Monde T, Nemoto F, Konakahara T, Takahashi Y
Central Research Laboratory, NEOS Co., Ltd., Kohka-gun, Shiga, Japan.
J Chromatogr A. 1999 Aug 13;852(2):475-85. doi: 10.1016/s0021-9673(99)00628-7.
The separation and characterization of octylphenol ethoxylate surfactants were carried out by reversed-phase high-performance liquid chromatography on branched fluorinated silica gel columns. For Triton X-100, simultaneous separation of octylphenol ethoxylate oligomers, positional isomers of octylphenyl group and butylphenol ethoxylate oligomers was achieved. These oligomers were completely separated and identified by means of MS spectra. Ethoxylated oligomers are eluted in the sequence from small to large oligomers. Fifty-five oligomers of Triton X-405 could be separated by using gradient elution. To separate octylphenol ethoxylate surfactant, non-end-capped branched fluorinated silica gel columns were superior to end-capped columns. The relationship between ln k' and methanol concentration was linear, indicating that branched fluorinated silica gel columns were operating in the reversed-phase mode. As Van 't Hoff plots of capacity factor for all oligomers gave straight lines, the equilibrium of conformation for the ethylene oxide chain might lay to one side of either zigzag or meander conformers.
采用反相高效液相色谱法，在支链氟化硅胶柱上对辛基酚聚氧乙烯醚表面活性剂进行了分离和表征。对于Triton X - 100，实现了辛基酚聚氧乙烯醚低聚物、辛基苯基位置异构体和丁基酚聚氧乙烯醚低聚物的同时分离。通过质谱对这些低聚物进行了完全分离和鉴定。乙氧基化低聚物按低聚物从小到大的顺序洗脱。采用梯度洗脱可分离出55种Triton X - 405低聚物。对于分离辛基酚聚氧乙烯醚表面活性剂，未封端的支链氟化硅胶柱优于封端柱。ln k'与甲醇浓度之间呈线性关系，表明支链氟化硅胶柱以反相模式运行。由于所有低聚物容量因子的范特霍夫图均为直线，环氧乙烷链构象的平衡可能偏向锯齿形或曲折形构象中的一侧。
