Ultrasound-assisted dispersive solid-phase extraction for the preconcentration of dyes in water samples

In this research, the magnesium ferrite/zinc oxide (MgFe2O4/ZnO) nanocomposite has been utilized as an effective adsorbent in the ultrasound-assisted dispersive solid-phase extraction (USA-DSPE) coupled to a spectrophotometric method for preconcentration of methylene blue (MB) and safranin O (SO) dyes. X-Ray diffraction (XRD), vibrating sample magnetometer (VSM), transmission electron microscopy (TEM), and field emission scanning electron microscopy (FESEM) analyses were performed to characterize and confirm the properties of the synthesized MgFe2O4/ZnO nanocomposite. Box-Behnken design (BBD) based on response surface methodol-ogy (RSM) was utilized to optimize the variables. The results of this research showed that the max-imum extraction efficiency was obtained at pH = 7, eluent volume of 140 mL, adsorbent amount of 1.53 mg, and ultrasonic time of 8 min. After optimization by RSM and using the Quadratic model, the extraction efficiency for MB and SO was 98.60% and 97.23%, respectively. The analysis of vari-ance (ANOVA) showed that the data obtained from the experiment were consistent with the pre-dicted model. Under optimal conditions, the calibration curve was linear in the range of 5- 1000 & mu;g/L (coefficient of determination of 0.9884) for MB and 10-1100 & mu;g/L (coefficient of deter-mination of 0.9973) for SO. The limit of detections (LOD) of the proposed method for MB and SO were determined as 1.5 & mu;g/L and 3 & mu;g/L, respectively. The relative standard deviations (RSD, n = 5) for MB and SO were obtained as 1.1% and 2.1%, respectively. The results of adsorbent recovery revealed that MgFe2O4/ZnO nanocomposite could be used several times without a signif-icant adsorbent efficiency loss. Furthermore, the findings of interference studies revealed that the presence of different ions does not cause substantial interference with the extraction of dyes. The environmental water samples analysis showed that the extraction efficiency for dyes was in the range of 93.74-99.11%.& COPY; 2023 The Author(s). Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).