Microfluidic detection platform with integrated micro-spectrometer system

•A microfluidic detection platform is presented for detection of preservatives in foods.•The platform comprises a PMMA microfluidic chip and a micro-UV detection system.•Sorbic acid concentrations of 15 commercial food samples are measured.•The measurement results deviate by no more than 7.5% versus official HPLC method.•The concentrations of benzoic acid, sulfur dioxide and formaldehyde are also measured.