Portable mass spectrometer with solid phase extraction using a novel amide-functionalized magnetic covalent organic framework adsorbent for on-site detection of two triphenylmethane dyes in aquatic products

Triphenylmethane dyes have been employed as fish drugs to prevent fish diseases for aquatic products in some developing countries. Their residues in aquatic products can bring significant impact on human health. In this study, an amide-functionalized magnetic covalent organic framework assisted magnetic solid phase extraction-portable mass spectrometry (MSPE-PMS) strategy was employed for on-site simultaneous detection of cationic triphenylmethane dyes, crystalline violet (CV) and brilliant green (BG). At the optimum MSPE conditions, the adsorbent was used to efficiently enrich CV and BG through magnetic solid phase extraction within 20 min with satisfied high concentration rate (10 folds). Then, the portable mass spectrometer was employed for simultaneous detection CV and BG within 0.2 min, with good linearity (R2 ≥ 0.9973) and low detection limit (0.135–0.694 μg kg−1). The results demonstrated the method is fast and simple and has the potential to detect triphenylmethane dyes residues in aquatic products quickly and on site.