Optimization of purging efficiency and quantification of organic contaminants from water using a 1-L closed-loop-stripping apparatus and computerized capillary column GC/MS

The authors have studied four ways of improving the recovery and precision of the 1-gallon closed-loop-stripping (CLS) apparatus: by purging a smaller volume; by better control of the temperature of the gas entering the filter and of the filter itself; by increasing the temperature of the sample water bath; by eliminating as much metal as possible in the closed loop. A 1 litre system has been developed and optimized for maximal purging efficiency of 1-chloroalkane standards spiked in water. The optimal conditions for efficient recovery were established and more than 95 per cent recovery was achieved for several chlorinated paraffins. Recovery studies of a 22 compound standard mixture of organics, using two 1-L CLS devices of different design, showed that both systems had similar recovery efficiencies, about twice as good as those for 1-gallon devices. Relative standard deviations showed similar improvement.