Real-Time Analysis of Gas Chromatograms with a Microcomputer System

Abstract
The real-time performance of a microcomputer system designed for dedicated control of gas chromatography and real-time analysis was studied to determine operating characteristics and accuracy of the peak-area integration algorithm. The software program developed to obtain peak areas used statistical criteria for the detection of the start, maximum value, and end of a chromatographic peak. The accuracy of the system was tested with propane-helium mixtures and by comparison to results obtained with off-line data reduction. The study showed that the real-time microcomputer system gave peak areas which were lower than the off-line results by less than 0.6 percent. The difference was shown to arise from truncation error in the double-precision octal mathematical subroutines, and to error in the assignment of a baseline at the peak-end.