LAUSR

BACKGROUND A naturally occurring material, namely sporopollenin (SP), was subjected to an easy physical surface modification process called a polydopamine coating. The treatment changed the acid-base properties of the surface, so that in the new form the SP surface gained a very attractive character for anionic dyes. OBJECTIVE The aim of the study was to develop preconcentration and subsequent spectrophotometric determination methods for two anionic colorants, brilliant blue (BB) and sunset yellow (SY), using polydopamine-coated (PDC) SP. METHOD The experiments were carried out in a column system, and the effects of experimental parameters were studied to determine optimal conditions for the quantitative, simultaneous spectrophotometric determination of the dyes. RESULTS The dyes could be detected at µg/L levels in their binary mixtures, so the detection limits were found to be 1.5 and 4.3 µg/L in the linear dynamic ranges of 0.0-3.5 and 0-8 µg/mL for BB and SY, respectively. The proposed material and procedure led to quantitative recoveries of between 95 and 100% for the dyes. CONCLUSIONS The procedure was applied to real food samples containing BB and SY and both dyes were successfully determined in liquid and solid foodstuffs. The mussel-inspired surface modification is proposed as a useful process to modify the surface of SP. HIGHLIGHTS The mussel-inspired polydopamine dip-coating method was adopted to modify the surface of SP for the first time. The PDCSP was successfully used to create a new adsorptive preconcentration method for simultaneous spectrophotometric determination of BB and SY in foodstuffs.