A STATISTICAL STUDY OF GAS CHROMATOGRAPHIC SYSTEMS EMPLOYING FLAME IONIZATION DETECTORS

A statistically designed and interpreted series of experiments were performed with three commercially available chromatographs equipped with flame ionization detectors and operated with columns and under the conditions normally encountered in routine operation. The results in many cases agree with those previously published in studies of the detector system alone. In both cases the effect of air flow rate, polarizing voltage, and hydrogen flow rate are approximately the same. The linear range of sample size found was somewhat less than several published ranges, probably because of greater background noise. Carrier gas flow rate affected response, in contrast to the behavior of an isolated flame ionization detector. An important interaction of carrier gas flow rate and sample size was found; hydrogen flow ratesample size, and hydrogen flow rate-carrier gas flow rate interactions were confirmed. It is suggested that additional carrier gas be added between column and detector to allow maintenance of optimum carrier flow rate. This study shows that system performance is generally less adequate than isolated component performance, being subject to various interactions which can most readily be examined by statistically designed experiments. © 1969.