Water Analysis by Solid Phase Microextraction Based on Physical Chemical Properties of the Coating

A novel and simple method using solid phase microextraction (SPME) with poly(dimethylsiloxane) fiber coating and linear temperature-programmed retention index (LTPRI) has been developed to quantify petroleum hydrocarbons in water. Partition coefficients (K fw) for the analytes in water and SPME were established for a series of aromatics, cycloalkanes and alkanes. There is a linear relationship between log K fw for each hydrocarbon series and LTPRI. The slope of the curves for all the series are the same and related to the partial free energy of solution for the hydrocarbon−fiber coating solution. The y-intercept of the plots is distinct for each group of hydrocarbons and related to Henry's law coefficients for each series. Therefore, the K fw for a series of hydrocarbons can be estimated using literature Henry's law coefficients. This method was used to quantify BTEX-contaminated water.