Electron capture detector response factors

The use of a volatile solvent, e.g., pentane, was not explored because of inherent limitations. Concentration of such extracts was not possible because of the volatility of the sample components. Therefore the maximum concentration factor that could have been achieved was limited by the partition coefficients of the compounds into the solvent used in the extraction. For most compounds this factor was estimated to be about 10 1. Furthermore, with CRMS and other general detectors, the solvent masking problem would still preclude observation of many compounds. Therefore, the method would be limited to detectors that are not responsive to the solvent used in the extraction. Recent work (3.4,5) has indicated that extraction with a volatile solvent is a viable approach for the analysis of a small set of compounds, e.g., the trihalomethanes, with an electron capture detector in drinking water samples where concentration factors of 10 1 or less are acceptable. 

The electron capture detector is a specific detector and as such the response factor will vary by the very nature of the... 

The major disadvantage of this technique is that the entire mixture must be separated and detected in the chromatographic system. All peaks must be standardized via response factors whether their analysis is needed or not. Internal normalization also requires that a detector be used that responds somewhat uniformly to all components. This technique cannot be used with electron capture and flame photometric detectors, for instance. 

In 1961 Lovelock and Zlatkis used a selective detector, in this case electron capture, to detect tetraethyllead with essentially no interference from hydrocarbons which have a much lower response factor and a photoionization detector to measure the total amount of hydrocarbons. They did not attempt to determine the various lead alkyls separately. 

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