Development of a dispersive solid phase extraction method based on copper-metal organic framework nanoparticles for the determination of lead at trace levels in stream samples

Abstract

In this study, a facile, rapid, and cost-effective method was developed for the determination of lead ions using copper-metal organic framework (Cu-MOF) nanoparticles based dispersive solid phase extraction (DSPE) in slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS) system. Cu-MOF nanoparticles were used as sorbents, and SQT was used to increase the residence time of lead atoms in the light path. The limit of detection (LOD) and limit of quantification (LOQ) of the Cu-MOF-DSPE-SQT-FAAS system were calculated as 7.1 µg L-1 and 23.5 µg L-1 under optimum experimental conditions, respectively. The regression coefficient (R2) was found to be 0.9967, and the linear operating range was determined between 15 and 300 µg L-1. Thanks to the developed method, a 103.7-fold improvement was achieved for the sensitivity of the traditional FAAS system by comparing the slopes of the linear calibration plot equations. The feasibility of the proposed method was investigated by spiking experiments with utilizing the stream water samples. The good recovery results obtained in the range of 90.8% to 127.1% demonstrated the applicability of the developed method to river water samples with high accuracy and precision. Cu-MOF structures have been employed for the first time for the preconcentration of Pb ions, and their prominent surface properties suggest that they may also be applicable for other analytical processes for different analytes.