An accurate but time consuming technique commonly used to analyze samples for quality control applications is Gas Chromatography / Mass Spectrometry (GC/MS). Although GC/MS is a well-known technique, analysis times are usually long and its output (a total ion chromatogram) can be hard to interpret. It is therefore of high interest to provide a faster screening technique that does not compromise the accuracy of results usually obtained with GC/MS. Chemical sensors are ideal for these types of applications because they provide fast chemical analysis with minimal sample preparation. In this study, a ChemSensor that incorporates well-known mass spectrometry technology with multivariate data analysis was used for two different applications.
The first application consists of the analysis of 13 different olive oils. The goal of this application was to classify unknown olive oils as degassed or pure. In order to validate the fast results obtained with the Headspace ChemSensor, traditional headspace GC/MS analyses were also performed. The second application illustrates the use of the ChemSensor to detect a compound not present in the standard samples. In this case, 2,4,6 trichloroanisole, responsible for the corky off-flavor of wine, was spiked into white wine and detected using HeadSpace (HS), Solid Phase MicroExtraction (SPME) and Stir Bar Sorptive Extraction (SBSE) using the GERSTEL Twister.
For the olive oil application two multivariate models (KNN and SIMCA) were created and all unknown samples were correctly classifi ed. Detection of trichloroanisole was possible at low ppm levels using HS; ppb levels using SPME and ppt levels using Twister sampling. Advantages of using the ChemSensor over traditional GC/MS analysis were faster analysis times and the option of creating customized reports that classifi ed samples as acceptable or rejected.
