Determination of multiclass contaminants in chilli powder based on magnetic multiwalled carbon nanotubes and UPLC-QTOF/MS

•A UPLC-QTOF/MS method was developed for multiclass contaminants in chilli powder.•A single run was used for analysis of 15 mycotoxins, 9 dyes and 192 pesticides.•The recoveries of 99.54% analytes were in the range of 60%∼120%.•The MEs of 85.6% of the analytes were in the acceptable range of 0.8 ∼ 1.2.•The clean-up process reduced sorbents consumption and improved the cleaning effect.