Classification of sample types using gas chromatography and chemometric analysis: Confirmation of brands, quality or origin.
Intertek MSG is able to undertake project work to develop and apply analytical systems which use complex chromatographic patterns and statistical analyses to classify samples types.
Such analysis systems may be used to provide confirmation of brand or quality or origin of material.
The samples may for example be industrial or consumer products such as textiles, fragrances, wine or fruit which may, after appropriate method development, allow the classification by geographic source, manufacturer, type of wine or fruit variety etc.
Analysis systems generally comprise of;
A means to transfer a representative part of the sample into the analysis system.
Separation and analysis of the distinguishing characteristic features which can be used to differentiate samples from different (known) classes. These (training) samples allow one to build a chemometric model that can be used to automatically assign unknown samples to the different classes.
The chemometric methods used to elucidate the distinguishing characteristics and provide analysis. These include principle component analysis (PCA), K nearest neighbours (KNN) and SIMCA. Fig. 1 shows an example SIMCA classification plot which differentiated 7 types of fibre on the basis of headspace-GC data.
The analysis systems used in Intertek MSG are based on gas chromatography or gas chromatography- mass spectrometry, although the chemometric approaches can equally well be used with analytical data from other sources such as NMR or FTIR spectroscopy.
Figure 1: SIMCA plot differentiating seven types of material using GC-MS
Extensive development work is required and the complexity of the final analytical procedure and potentially, capital investment in equipment, would normally mean such projects would be suitable only for ongoing routine analyses of significant volume.
For further information; call Bernard Fields +44 (0) 1642 435745 or email Bernard.Fields@Intertek.com