Sensitive determination of lead in an herbal tea matrix utilizing carbon doped CuO nanoparticles as solid phase adsorbent

This study presents the development of an efficient solid-phase microextraction (SPME) strategy using C-doped CuO nanoparticles for the trace determination of lead by using flame atomic absorption spectrometry (FAAS). The C-doped CuO nanoparticles were synthesized by the precipitation method. The morphological and structural properties of the nanoparticles have been investigated by XRD, SEM, and EDX analysis. A comprehensive optimization study was conducted to maximize the extraction efficiency by evaluating various experimental factors including buffer solution volume/type, mixing duration, sample volume, adsorbent quantity, and desorption solution volume/concentration. Under the optimum conditions, the limit of detection (LOD), the limit of quantification (LOQ), and the linear dynamic range were calculated as 0.011 mg/kg, 0.035 mg/kg, and 0.03–0.40 mg/kg, respectively. For the proposed SPME procedure, an enhancement factor of 82-fold was calculated by comparison of the detection sensitivity of the developed method with direct FAAS measurements.