The Response Factor Method

The problems with this approach are 1) without comparing the peaks to a standard or a set of standards, it is not known whether the result is a weight, volume, or mole percent, and 2) the instrument detector does not respond to all components equally. For example, not all components will have the same thermal conductivity, and thus the thermal conductivity detector will not give equal sized peaks for equal concentrations of any two components. Thus, the sum of all four peaks would be a meaningless quantity, and the size of peak B by itself would not represent the correct fraction of the total. 

It is possible, however, to measure a so-called response factor for the analyte, which is the area generated by a unit quantity inj ected, such as a micro liter or microgram. The procedure is to inject a known quantity of the analyte, measured by the position of the plunger in the syringe (microliters) or by weighing the syringe before and after injection (micrograms). The peak size that results is measured and divided by this quantity  

The quantity of analyte in an unknown sample is then determined by measuring the peak size of the analyte resulting from an injection of a known quantity of an unknown sample and dividing by the analyte s response factor  

In this method, only the peak of the analyte needs to be measured in the four-component mixture in order to quantitate this component. 

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The samples taken from the reactors were analyzed by gas chromatography (HP-FID 5890) using a 5% phenyl polyxilosane capillary column. The chromatograph was calibrated using pure samples of the products and reactants. Calculations were done using the response factor method [11]. 

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