Magnetic graphitic carbon nitride nano-composite for ultrasound-assisted dispersive micro-solid-phase extraction of Hg(II) prior to quantitation by atomic fluorescence spectroscopy

Meng-Ting Shi; Xin-An Yang; Wang-Bing Zhang

doi:10.1016/j.aca.2019.04.062

Magnetic graphitic carbon nitride nano-composite for ultrasound-assisted dispersive micro-solid-phase extraction of Hg(II) prior to quantitation by atomic fluorescence spectroscopy

Anal Chim Acta. 2019 Oct 3:1074:33-42. doi: 10.1016/j.aca.2019.04.062. Epub 2019 Apr 29.

Authors

Meng-Ting Shi¹, Xin-An Yang¹, Wang-Bing Zhang²

Affiliations

¹ Department of Applied Chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China.
² Department of Applied Chemistry, Anhui University of Technology, Maanshan, Anhui 243002, PR China. Electronic address: zhangwb@ahut.edu.cn.

PMID: 31159937
DOI: 10.1016/j.aca.2019.04.062

Abstract

A nanosheet structure of Fe₃O₄/g-C₃N₄ magnetic composite has been prepared and utilized as adsorbent for the ultrasound-assisted dispersive magnetic micro-solid-phase extraction of the ultra-trace inorganic mercury [Hg(II)]. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Fouries transform infrared spectroscopy images manifested that the hydrothermal systhesis promoted the binding of Fe₃O₄ particles with g-C₃N₄. The enrichment performance of composites depended on their compositions, and the recovery of Hg(II) on C-m30 (with Fe₃O₄/g-C₃N₄ mass ratio 2:3) was higher than that on other ratios. Recorded data showed that ultrasound wave was an effective method for reducing the agglomeration of magnetic materials and enhancing their adsorption properties. The Hg signal obtained by 80% power input is 3.2 times stronger than the signal by strring mode. X-ray diffraction characterization of the recovered adsorbent showed that g-C₃N₄ needed to be updated after repeated use for four times. In addition, competitive adsorption may be main factor affecting the inhibitory effect of high concentration methylmercury on inorganic mercury. Under the optimized conditions, the detection limit of the proposed method was 1.4 ng L^-1 and relative standard deviation of 4.6% for 0.05 μg L^-1 Hg(II) was obtained. The linear calibration range was 0.005-0.4 μg L^-1. The accuracy of the method was verified through analysis of the certificated reference materials. The proposed method has been applied in the determination of inorganic Hg in natural water samples.

Keywords: Fe(3)O(4)/g-C(3)N(4); In situ slurry chemical vapor generation; Magnetic micro-solid-phase extraction; Mercury; Ultrasound-assisted dispersive.