Determination of trace cobalt (II) in spices samples by ultrasonic assisted cloud point extraction with spectrophotometry

Abstract

In this study, ultrasonic assisted cloud point extraction (UA-CPE) method was developed for the determination of Cobalt (II) (Co(II)) in spices. After extraction and preconcentration, the Co(II) contents of the samples were determined by UV–VIS. After complexing with Ponceau Xylidine (PX) and EDTA in the presence of cationic surfactant, CTAB at pH 4.0 with Britton–Robinson (BR) buffer, Co(II) ion was withdrawn the surfactant-rich phase of nonionic surfactant, Triton X-114 (TX-114). The concentrated surfactant-rich phase containing the analyte was diluted with ethanol to a volume of 1.0 mL and then analyzed by UV–VIS spectrophotometer. The various analytical parameters affecting the UA-CPE yield were investigated and optimized. Analytical data achieved after optimization: limits of detection (LOD) and: limits of quantification (LOQ) are 0.76 and 2.59 μg L−1, respectively; The calibration curve is rectilinear for Co(II) with changed calibration sensitivity in the range of 1–10 and 10-210 μg L−1. The precision (as RSD%) is 4.8. This optimized method was applied in the analysis of various spice samples.