Synthesis of 14C-labeled alkyl polyoxyethylene detergents

Procedures for the synthesis and purification of two 14C-labeled alkyl polyoxyethylene detergent preparations are described. One of the preparations consisted mainly of [14C]dodecyloctaoxyethylene ether, the other consisted mainly of [14C] octylhexaoxyethylene ether, with critical micellar concentrations of approximately 50 microM and 10 mM, respectively. Condensation of alkyl bromides with fractionated polyethyleneglycol resulted in less polydisperse products than conventional ethylene oxide condensation. Highly purified detergent species could easily be obtained from the preparations by thin-layer chromatography. Their use as tracers greatly simplifies determination of detergent concentration during protein solubilization and fractionation.