US 4,468,742 AGranted

Microprocessor system for quantitative chromatographic data analysis

AssigneeThe Regents of the University of California

InventorsDonald J. Jenden, Robert W. Silverman, Frederick C. Lee

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Abstract

Quantitative chromatography is widely used in many fields to measure the amount of a compound present in a mixture. A series of Gaussian-like peaks are generated as output, and the size is conventionally measured by peak area or peak height determinations. The microprocessor-based analysis system of the present invention is designed to "learn" the characteristics of a set of chromatographic peaks. Retention time and peak width parameters are used to detect and measure selected peaks by a convolution procedure based on a matched filter. The filter is applied to peaks in the neighborhood of selecting peak times which have a shape closely resembling that of a control sample. The system is built around a microprocessor with a wide dynamic range analog-to-digital conversion input stage. Operator interaction with the programs and the printing of output results is facilitated.

Claims23

Dependent claims

In the quantitative analysis of a series of samples as to the contents therof in apparatus producing an output signal reflecting the quantity of a component as a peak of substantially Gaussian shape at a fixed time associated with the component, the improved method comprising the steps of:

(a) injecting into the apparatus a standard sample containing a known amount of the compound to be analyzed;
(b) measuring the time to the output of a signal peak associated with the compound to be analyzed to establish the retention time of the apparatus associated therewith;
(c) saving said established retention time;
(d) establishing a data filter by scaling a Gaussian based curve to the curve of said signal peak;
(e) injecting into the apparatus a series of samples containing unknown amounts of said compound to be analyzed;
(f) for each sample of said series, sequentially convolving said data filter to the output signal for a sequence of time divisions on either side of and in close proximity to said saved retention time following the injection of said sample to establish a figure of merit reflecting the size of the output signal waveform at its peak to said data filter curve;
and,
(g) determining the quantity of component for each of said samples of said series as a function of said figure of merit relative to the known quantity in said standard sample.

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Dependencies are inferred from the claim text.