Multivariate detection limits for selected ion monitoring gas chromatography — mass spectrometry

Abstract

A multivariate approach is developed for estimating detection limits for selected ion monitoring gas chromatography—mass spectrometry. This technique is directly based on the Hubaux—Vos technique which regresses instrument response onto concentration. The statistics of this regression are used to estimate the detection limit as the lowest true concentration which will, with high probability, be significantly different from a blank and therefore be considered a positive sample. The proposed multivariate approach forms a composite instrument response from all mass channels monitored using the first principal component. The instrument and method detection limits estimates using this approach are shown to be directly comparable to estimates obtained using the conventional univariate approach.