Dispersive micro-solid phase extraction coupled with spectrophotometric using (MgFe CLDH)/GO magnetically separable sorbent for pre-concentration of anionic food dyes in water samples

In the present study, a method was described for the extraction of Sunset Yellow (SY) and Tartrazine (TZ) as anionic food dyes in actual samples by using magnetic calcined layered double hydroxide onto graphene oxide (MgFe CLDH)/GO (called MgO/MgFe2O4/GO) sorbent. The analytes were accumulated on MgO/MgFe2O4/GO-NCs with more detail recognized by XRD, FESEM, EDS element mapping, VSM and FTIR methods. The prepared nanocomposite (NC) was employed as an extractive phase for dispersive micro-solid phase extraction (D-μ-SPE) of SY and TA from actual samples. Then, the extracted SY and TZ dyes were analysed by UV-vis spectrophotometer. Main variables related to the extraction process including pH, nano composite mass, sonication and vortex time and eluent volume were optimized by central composite design (CCD). The optimum conditions obtained for pH, nano composite mass, sonication and vortex time and eluent volume were 6.0, 0.02g, 16 sec and 6.40 min, and 500 μL, respectively. The extraction recovery equal to 96.31% and 97.66% for SY and TZ, respectively obtained from the predicted model, was in agreement with the experimental data (95.32±2.33% and 96.89±1.84%). In addition, under the optimal conditions, the calibration curve was found out to be linear over the concentration range of 0.5-2.50 mg L-1 with R2 >0.98. The LODs ranged from 0.14 to 0.16 mgL-1. Furthermore, the enrichment factors (EF) were achieved in the range of 20.65 to 36.66 with pre-concentration factor (PF) of 20. In the meantime, the obtained assay accuracy in the analysis of medical extract of Miranda Drink, Saffron and water samples fell within the range of 93.00%-107.00%, whilst the precision expressed RSD lower than 3.50%.