Traceability study of hay with a mass spectrometer based on ion-molecule reactions of krypton, xenon and mercury using multivariate data analysis

Abstract

The application of mountain hay for wellness purposes has led to a substantial valorisation. To assure the quality associated with the high standards of production, which are often related to a characteristic distribution of plants and a variety of essential oils, a mass spectrometer, based on ion-molecule-reactions (IMR) of mercury, krypton and xenon, was employed to analyse characteristic VOCs of hay such as coumarin or typical monoterpenes and then used to develop an approach for the traceability of single hay samples based on concepts of multivariate statistics. The application of the primary gases to aqueous solutions of the pure compounds shows their suitability to deal with this problem, reveals important factors for the creation of a measurement set-up of such gas mixtures and indicates different mechanisms for the fragmentation, as shown for coumarin. The limit of determination (3*sR/SEN) for aqueous solutions of p-cymene is 0.13 mg L−1 using PLS1 and the presented combined mercury and xenon set-up, which confirms that this strategy is appropriate for an integration of compounds, which are present in low concentrations only, into a qualitative model. The results of the principal component analyses (PCA) of 136 hay samples were verified for the suitability to characterize single types of hay using three measurements of nine mountain hay samples, three normal hay samples and three aftermath samples for evaluation and applying SIMCA for classification at a significance level of 5%. The traceability of mountain hay samples is good (93% correctly classified) and can be used to protect these valuable samples.