Ultrasonic-assisted d-µ-SPE based on amine-functionalized KCC-1 for trace detection of lead and cadmium ion by GFAAS

Abstract

In this work, an efficient ultrasonic-assisted dispersive micro-solid phase extraction method (ultrasonic-assisted d-µSPE), based on amine-functionalized mesoporous silica KCC-1, was successfully utilized for the extraction and highly sensitive detection of lead and cadmium ions in water and agricultural products. The lead and cadmium ions were determined by graphite furnace atomic absorption spectrometry (GFAAS). In addition, the impact of significant factors, including pH, sorbent mass, and the sonication time in the retention step and concentration of the eluent, volume of the eluent, and the sonication time in the elution step was optimized using the Box-Behnken design. The obtained models by the Box-Behnken design for the retention and elution steps were meticulously evaluated. The results show that the proposed models for predicting and optimizing influencing parameters in the pre-concentration procedure have good adequacy and accuracy. In the optimal pre-concentration conditions, the calibration curves were linear in the range of 0.08–1.4 µg/L for cadmium and 0.6–30 µg/L for lead ions. The limits of quantification (LOQ) and the limits of detection (LOD) were 0.08 µg/L and 0.02 µg/L for cadmium ions and 0.60 µg/L and 0.18 µg/L for lead ions. The obtained relative recovery values from the analysis of spiked real samples were in the 97.2–104.0 % and 98.0–107.0 % range for cadmium and lead ions, respectively. Intra-day and inter-day relative standard deviations were 4.4 and 6.1 % for cadmium ions and 2.9 and 4.9 % for lead ions (1.0 µg/L; Number of replicate = 3).