Noise and background reduction method for component detection in chromatography/spectrometry

A method of identifying and quantifying the chemical components of a mixture of organic materials comprising;

• a first step of subjecting said organic material to chromatography to separate components of said mixture and a second step of subjecting the separated materials to spectrometry to detect and identify said components, wherein said chromatography and spectrometry is performed by
• a) injecting a sample into a column;
• b) separating components by partitioning at different rates in the column;
• c) passing separated components into a spectrometer;
• d) obtaining a series of spectra to detect all species present;
• and
• e) storing the spectra in a computer file;
• the improvement comprising enhancing the spectral data by a variable selection using the following steps:
• i) smooth the spectroscopic variables;
• ii) obtain the mean value of the intensity of the spectroscopic variables;
• iii) subtract the mean value obtained in step ii from the smoothed variables obtained in step i;
• iv) normalize the output of step iii and the original spectroscopic variables;
• v) compare the values of step iv to obtain a measure of similarity for each spectroscopic variable;
• vi) determining a threshold value of similarity measurement so as to reject unwanted signals;
• vii) select only those spectroscopic variables whose similarity measurement is over the threshold value;
• and
• viii) plot the sum of the selected variables versus time to obtain the enhanced chromatogram.