Solventless sampling of phthalate esters

An environmentally friendly method to passively sample six phthalate esters in water has been devised. The sampling device consists of a semi-permeable membrane, which the analytes diffuse through and are collected onto Tenax TA. The Tenax TA was then thermally desorbed with a helium stream into a gas chromatograph-mass spectrometer (GC-MS) after the sampling period. Samplers were exposed to water samples for known periods of time at known concentrations to create time-weighted average (TWA) plots. For all six phthalates the resulting TWA plots had linear correlations, allowing for the determination of permeation constants for the phthalates. The lag time for each phthalate was also determined using this method. An advantage of this method is that no solvents are used. The analytes are removed from the Tenax TA using thermal desorption rather than liquid extraction.