Morphology-maintaining synthesis of copper hydroxy phosphate@metal–organic framework composite for extraction and determination of trace mercury in rice

• Published in: Food chemistry Vol. 343; p. 128508
• Main Authors: Song, Chenchen, Zhang, Yanhao, Li, Xinglin, Ouyang, Gangfeng, Cui, Jiting, Zhang, Ling, Yu, Ajuan, Zhang, Shusheng, Cui, Yuanyuan
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2021
• Subjects: Adsorption; Adsorption mechanism; Atomic fluorescence spectroscopy (AFS); Copper - chemistry; Copper hydroxy phosphate@MOF; Food Analysis - methods; Food Contamination - analysis; Hydrogen-Ion Concentration; Kinetics; Mercury - analysis; Metal-Organic Frameworks - chemistry; Oryza - chemistry; Phosphates - chemistry; Photoelectron Spectroscopy; Rice sample; Self-template; Solid phase extraction (SPE); Spectrometry, Fluorescence; Spectrum Analysis, Raman; Sulfhydryl Compounds - chemistry; Thiadiazoles - chemistry; Trace mercury; Solid phase extraction (SPE); Copper hydroxy phosphate@MOF; Self-template; Trace mercury; Rice sample; Adsorption mechanism; Atomic fluorescence spectroscopy (AFS)
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.128508

•A morphology-maintaining DMP-Cu decorated by DMTZ was prepared and characterized.•The CHP facilely served as the source of metal and in situ converted to MOF shell.•A SPE method with AFS was developed for the determination of trace mercury in rice.•The Hg2+adsorption were fitted by pseudo second-order kinetics and Langmuir model.•XPS and Raman spectra verified the interaction between Hg2+ and S/N groups on DMP-Cu. A novel copper hydroxy phosphate@MOF composite DMP-Cu decorated by 2, 5-dimercapto-1, 3, 4-thiadiazol was facilely prepared and characterized. A dispersive SPE strategy using DMP-Cu as adsorbent combined with atomic fluorescence spectroscopy was developed for the selective capture of trace total mercury in rice sample. The adsorption mechanism showed that the Hg2+ removal process was fitted with pseudo second-order kinetics and the Langmuir adsorption model. The adsorbent was easy to be regenerated and the maximum adsorption capacity for the removal of Hg2+ was 249.5 mg g−1 at the optimal pH of 4. X-ray photoelectron spectroscopy and Raman spectra verified the selective and strong interaction between Hg2+ and thiol/nitrogen-containing functional groups of DMTZ on DMP-Cu. The trace total mercury in rice samples was determined with detection limit of 0.0125 ng mL−1 and relative standard deviation below 6%. The high recoveries were obtained in range of 98.8–109% for the spiked rice samples.