Sustainable disposable chitosan dip-coated paper-based sorbent for extraction of sunset yellow from food samples and pharmaceuticals.

Sunset yellow (SY) is a synthetic azo dye that has been used widely in food industries and is linked to numerous health problems, especially with children. In this work, a straightforward, affordable, and eco-friendly paper-based extraction method was devised for SY extraction and subsequent spectrophotometric determination. The extraction method relied on the use of a disposable and biodegradable chitosan (CHT)-modified paper-based sorbent. The prepared sorptive sheets were characterized using scanning electron microscopy, energy-dispersive X-ray analysis, and water contact angle measurements. SY adsorption onto CHT was best described by the pseudo-first order kinetic model. The different parameters governing the extraction efficiency of the devised paper-based sorbent were investigated. SY was most effectively captured on paper treated with 0.6% CHT after 20 min and was released using a mixture of methanol and 0.1 N HCl (1:1, v/v) after 25 min, achieving an enrichment factor of 2.4. The absorbance intensity at 482 nm showed a good correlation with SY concentration over the range of 10-60 μg/mL. The devised approach showed recovery values between 99 - 105% and enabled the quantification of SY in spiked orange juice, spiked carrot juice, pediatric syrup and carbonated orange beverage without the need for specific reagents, costly instrumentation, or tedious extraction processes. The AGREEprep tool demonstrated the superior environmental impact of the developed method compared to the reported procedures for cloud point extraction.