Evaluation of solid phase microextraction for the analysis of hydrophilic compounds

Two commercially available solid phase microextraction (SPME) fibers, polyacrylate and carboxen/polydimethylsiloxane (PDMS), were evaluated for their ability to extract hydrophilic compounds from drinking water. Conditions, such as desorption time, desorption temperature, sample temperature, sample stirring, methanol concentration in the sample, and ionic strength of the sample, were optimized for 12 hydrophilic compounds (e.g., amines and alcohols) with both fibers. Accuracy, precision, and method detection limits (MDLs) were determined for the target analytes with both fibers. In general, both fibers exhibited excellent accuracy and precision in the range of 91-110% and 1.0-13%, respectively. The carboxen/PDMS fiber extracted these hydrophilic compounds from water with 10 to 100 times lower MDLs (0.10 to 15 micrograms/l) than the polyacrylate fiber (1.5 to 80 micrograms/l). The MDLs of the carboxen/PDMS fiber demonstrate that SPME is a feasible approach for extracting hydrophilic compounds from drinking water.