Main content area

Synthesis and Characterization of a Molecularly Imprinted Silica Gel Sorbent for the On-Line Determination of Trace Sudan I in Chilli Powder through High-Performance Liquid Chromatography

Wang, S., Xu, Z., Fang, G., Duan, Z., Zhang, Y., Chen, S.
Journal of agricultural and food chemistry 2007 v.55 no.10 pp. 3869-3876
hot peppers, powders, artificial colors, azo dyes, food contamination, food analysis, high performance liquid chromatography, adsorption, adsorbents, silica gel
A highly selective imprinted polymer was synthesized by a surface molecular imprinting technique in combination with a sol-gel process. The imprinted polymer was evaluated by FT-IR and static and kinetic adsorption experiments. The results showed that the imprinted sorbent exhibited good recognition and selective ability, offered a faster kinetics for the adsorption and desorption of Sudan I than the non-imprinted sorbent, a saturated binding capacity (Q(max)) that reached 33.47 mg g⁻¹. The prepared sorbent was applied for the determination of trace Sudan I through on-line solid-phase coupled with high-performance liquid chromatography (SPE-HPLC). With a loading flow rate of 1.5 mL min⁻¹ for sampling 50 mL, an enrichment factor of 1266 was achieved. The detection limit (S/N = 3) was 1.2 ng L⁻¹, and the peak area precision (RSD) for five replicate detections of 0.01 micrograms L⁻¹ Sudan I was 3.66%. The Sudan I in the chilli powder from the local market was determined at three levels (0.25, 0.5, and 1.0 ng g⁻¹) with recoveries ranging from 80.31 to 94.02%.