| The New Jersey Department of Environmental Protection Source Water Assessment Program was designed to model and trace groundwater contaminants detected in drinking water back through the hydro geologic system to their sources. The purpose of this dissertation was to examine the effectiveness of the methodology that was used to analyze water samples for semi volatiles organic contaminants.; Two methods were selected for analysis: a solid phase extraction gas chromatography/ion trap mass spectrometry (SPE-GC/ITMS) method and a solid phase micro extraction method (SPME-GC/ITMS).SPE proved to be an ideal method for hydrophobic analytes (having high octanol-water partition coefficients, Kow), but could not recover hydrophilic analytes, those having low Kow values. This was because the hydrophobic sorbent used in the SPE method could not effectively adsorb the hydrophilic analytes.; The SPME method, with use of a Carbowax/Divinylbenzene (CW/DVB) fiber, was able to extract both the hydrophobic analytes the SPE method performed well for as well as the hydrophilic analytes that proved problematic for SPE. A number of factors were then optimized for the SPME method including: sample salinity, extraction time, extraction temperature and pH to finalize a method that was able to extract analytes with a wide range of Kow values.; A model was then developed to predict if the CW/DVB fiber could adsorb an analyte based on the analytes physicochemical characteristics. Three properties were modeled: hydrophobicity (log Kow), molecular weight and Henry's Law Constant. Using multiple linear regression calculations it was determined that an analytes hydrophobicity determines whether it will be adsorbed by the fiber. A linear operational range exists (R2 = 0.96), across all compound classes, for log Kow values ranging from 2 to 5.3. Over this range the amount of analyte extracted will increase linearly with increasing log Kow values.; Field samples, ground and treated waters, were then used to compare the two methods. SPE proved to have lower background contamination levels while SPME was able to recover a greater number of low level analytes. The SPE method favored chlorinated disinfection byproducts, while SPME favored brominated disinfection byproducts, illustrating the need for both analysis techniques to be used in further studies. |
