An adapted, purge and trap GC-MS technique using heated, 100mL aqueous samples was evaluated for the determination of organics in a water quality survey. The 51 volatile organics consisted of 7 aromatic, 40 halogenated aliphatic and aromatic, and 4 other compounds and included the purgeable priority pollutants listed by the U.S. E.P.A. Detection limits 1 #x3BC;g/L, analytical precision 15 RSD, recoveries 70, and precision 20 RSD for recoveries over all three concentrations were generally obtained for the 51 standards, each spiked at 1, 10, and 50#x3BC;g/L into purified water. The few instances of abnormal recoveries, poor detection limits, and poor analytical precision were often related. Improved detection limits were obtained for several water soluble and a few halogenated compounds when the concentrator trap composition was changed, transfer line temperature was decreased, and the sparger vessel temperature was increased. For survey control samples, i.e. spiked purified water in bottles transported and stored for up to 1 month, recoveries were 90#xB1;15 of those obtained for fresh calibration samples and the analytical precision for replicate control samples was 20 RSD for most of the organics. The importance of control samples in surveys was emphasized by the occurrence of some anomalous results.
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