Utility of solid-phase extraction coupled with spectrophotometry for a novel green nano determination of copper(II) using 4-((furan-2-ylmethylene) amino)-5-methyl-4H-1,2,4-triazole-3-thiol
Alaa S. Amin, Mostafa Y. Nassar, Aya Gomaa
Abstract
A highly sensitive, selective and accurate method has been developed to determine ultra trace amounts of copper(II) by solid-phase extraction (SPE). The following parameters such as pH, concentration of the reagent, Triton X-100, reversed-phase Amberlite IR-120, equilibrating temperature and centrifuging time were evaluated to enhance the sensitivity and extraction efficiency of the proposed method. The method has been based on copper(II) and 4-((furan-2-ylmethylene) amino)-5-methyl-4 H-1,2,4-triazole-3-thiol (FAMT) reaction, followed by solid-phase extraction (SPE) of Cu(II)-FAMT with a reversed-phase Amberlite IR-120. This was performed by using borate buffer solution of pH 7.6 in the presence of Triton X-100 medium. FAMT reacts with copper(II) to form a deep green complex with molar ratio of (2: 1) (FAMT: copper). An enrichment and improvement factor of 200 and 540, respectively, were obtained by elution of the complex from the resin with a minimal amount of dimethylsulfoxide (0.5 mL). The molar absorptivity of the complex was 6.49 × 106 L mol−1 cm−1 at 499 nm. Beer’s law was obeyed in the range 5.0–190 ng mL−1 of the measured solution. After optimising the instrumental and experimental parameters, the maximum values for quantification and detections limits of 100 mL sample system were 5.40 and 1.64 ng mL−1. The suggested method has been successfully applied for determination of copper ions in various environmental (water, vegetables, food, and biological) samples.