Headspace Solid-Phase Microextraction for Determination of Micellar Solubilization of methyl tert-butyl ether (MTBE)

Headspace analysis using solid-phase microextraction (SPME) was tested as a rapid method to evaluate micellar solubilization of methyl tert-butyl ether (MTBE) with sodium dodecyl sulfate (SDS) and cetylpyridinium chloride (CPC). At equilibrium between aqueous phase and vapor phase, free MTBE in vapor phase (i.e., not solubilized MTBE by SDS or CPC) was analyzed by GC-FID (Hewlett Packard 5890 series II) equipped with a capillary HP1 column (30 m×0.25 mm). This method showed a good analytical performance such as linearity of calibration curve and precision (RSD less than 5%). Extent of MTBE solubilization was expressed as a function of molar ratio of SDS to MTBE and CPC to MTBE, and was saturated at about 57% and 37% with over the value of ratio 13 for SDS and CPC, respectively. This technique can be applied to analyze micellar solubilization potential of various surfactants on volatile and semi-volatile compounds.