<p>A) A plot of identified analytes as a function of extraction time. Nonlinear regression fitting the hyperbolic extraction curve yields a Y<sub>max</sub> of 114+/−3 for the CAR-DVB-PDMS fiber (R<sup>2</sup> = 0.9937) and 94+/−4 for the PA fiber (R<sup>2</sup> = 0.9791). The PEG plot could not be extended beyond 20 min due to an unknown analyte overwhelming the MS detector. Also shown in this plot is the number of identified analytes obtained from a sample that was pretreated by boiling for 5 min before extraction. Essentially no difference in analyte number or composition is observed with the pretreated sample (CAR-DVB-PDMS+boiled sample) relative to an untreated sample (CAR-DVB-PDMS). All samples were analyzed in duplicate. See text for further discussion. B) A plot of area under the chromatographic curve as a function of time for the indicated analytes obtained using the CAR-DVB-PDMS fiber. Differences in extraction rates for the indicated metabolites are apparent.</p
