adsorption and solid-phase extraction uv-vis spectrophotometric determination of rhodamine 6g in food sample using marble powder waste

Abstract: the solid-phase extraction (spe) as a routine technique of sample preparation is used in the sorbent extraction method, and this technique has diverse applications such as food analysis [1]. nowadays, natural sorbents have been highly regarded by researchers in various industries, especially in the food industry due to their non-toxicity, cost-effectiveness, lack of need for complex production processes, and abundantly available [2]. these sorbents are usually prepared from agricultural, mineral, and construction wastes. natural adsorbents can be a lucrative alternative to synthetic and commercial adsorbents in spe methods. in this study, we provided marble powder wastes (mpw) from doroud stonework, lorestan, iran, and we washed and calcined it. we employed mpw to adsorb and detect trace amounts of rhodamine 6g in food samples using the solid-phase extraction uv-vis spectrophotometry method. the structure and morphology of mpw were characterized by ft-ir, xrd, and fe-sem analysis. a three-factor, three levels of box-behnken design was utilized to explore the optimum condition of the sorbent mass, ph, and uptake time. the sorption percent of rhodamine 6g at 544 nm was considered as the dependent variable against these parameters. according to information obtained from anova analysis, the model's f-values and p-values were calculated at 193.57 and 0.103, which illustrate the factors in the models have a substantial effect on the response. under optimum conditions: adsorption percent, linear range, the limit of detection, and limit of quantification were obtained at 97.60±1.04, 50-20000 μg.l-1, 8.50 μg.l-1, and 28.35 μg.l-1, respectively. the enrichment factor was determined at 66.66 and relative standard deviations for 6 repetitions are achieved at 3.68 %. this spe method by mpw adsorbent has been successfully feasible for the determination of rhodamine 6g content in food samples. this operation was carried out by adding 50, 100, and 200 μg.l-1 of rhodamine 6g in 5 mg/l of jelly, orange juice, saffron ice cream, and tap water in the analytical laboratory of lorestan university. finally, the reusable, good lod, notable rsd %, short-time extraction, selective, sensitive, low-cost, and high enrichment factor are benefits of this spe method.