US 6,694,265 B2 · Method and apparatus for determining the boundaries of a detector response profile and for controlling processes

Abstract

An improved method and apparatus for identifying peaks and for determining the boundaries of those peaks, and boundaries of multiple peaks and shoulders within chromatograms. The method and apparatus effects real time identification and determination of the boundaries of these peaks for the purpose of fraction collection. The method and apparatus determines the boundary of a peak within a detector response profile that comprises data points plotted graphically on an X and Y-axis wherein the X-axis represents a first variable and the Y-axis represents a second variable, each variable having a value. The plot at each of the data points has a slope. Data points having a slope which deviates from a consistent value define a peak, and data points having a slope with a consistent value define a baseline.

Claims21

Dependent claims

A method for determining the boundary of a peak of a detector response profile said peak corresponds to a chemical entity flowing through a conduit, the method comprising the steps of:

determining the presence of a peak having an apex and two sides;
selecting a first data point and a second data point;
determining a slope-difference threshold wherein the slope-difference threshold can be a fixed value, or can be determined by the properties of the peak under analysis;
determining a slope of a line and a slope of a peak profile at the first data point and a second data point of the line;
forming a first difference and a second difference wherein the first difference is the difference between a peak slope on an up-slope at the data point minus a slope of the line and the second difference is the difference between a peak slope on a down slope at the data point minus the slope of the line;
identifying the data point with the larger difference;
wherein if that difference is greater than a slope-difference threshold, then that point is moved outward by one sample point and if the difference is less than the slope-difference threshold, no further adjustments are made;
and
determining a baseline by the final data points.

6 more elements

Dependencies are inferred from the claim text.

Method and apparatus for determining the boundaries of a detector response profile and for controlling processes

Life of this patent

Method and apparatus for determining the boundaries of a detector response profile and for controlling processes

Life of this patent

Abstract

Claims21