Evaluation of the sample treatment influence in green and sustainable assessment of liquid chromatography methods by the HEXAGON tool: Sulfonate-based dyes determination in meat samples

Abstract

Green and Sustainable assessment of sample treatment has been carried out when using liquid chromatographic methods in food analysis. Particularly, published sulfonate-based dyes determination by conventional liquid chromatography with diode array (HPLC-DAD) or mass detectors (HPLC-MS/MS) was selected as starting point. Greenness-sustainability have been quantitatively evaluated by means of the HEXAGON tool, in which sample treatment and method characteristics noticeably play a key role in defining the figures of merit of the analytical procedure. According to the evaluation results that are represented in a hexagon pictogram with an overall score from 0 to 4 (the lower the score, the greater contribution), a new analytical method is proposed by means of both minimizing and miniaturizing sample treatment step. In-tube solid-phase microextraction online coupled to capillary LC (IT-SPME-CapLC-DAD) provided a more green and sustainable alternative to current food dyes analysis without losing sensitivity (LODs 0.5-1 µg/g sample). The proposed method was tested on chicken meat samples (2 g), using ethanol-ammonia-water mixture (80:1:19, v/v/v; 5 mL) as extraction solution. The arithmetic means of the HEXAGON scores (sav) were: 1.71, 2.57 and 2.71 for IT-SPME-CapLC-DAD, HPLC-DAD and HPLC-MS/MS, respectively. The proposed method was closer than the others tested to a hypothetical LC procedure without sample treatment, which provided a sav value of 1.