Electron capture detection in high-speed narrow bore capillary gas chromatography. Fast and sensitive analysis of PCB's and pesticides

In this work the combination of high-speed narrow-bore capillary GC with electron capture detection is evaluated. The make-up gas flow rate is a key parameter in the successful coupling of narrow-bore columns on ECD detection. The make-up flow has to be as high as possible to eliminate peak tailing caused by the large detection cell volume. The sensitivities at these elevated make-up flow rates (400 to 1000 ml/min) were even better than those obtained with normal make-up flow rates. Detection limits of 0.1 pg were obtained, resulting in minimum detectable concentrations of approximately 0.2 ppb. The performance of the system is illustrated by several high-speed analyses of environmentally relevant samples