title: Dynamic interaction between melamine and cyanuric acid in artificial urine investigated by quartz crystal microbalance.
abstract: The dynamic interaction between melamine (M) and cyanuric acid (CA) in artificial urine was investigated by a flow injection analysis-quartz crystal microbalance (FIA-QCM) system. Melamine was used as the recognition element and immobilized onto the QCM gold surface. The process of M and CA interaction was recorded by FIA-QCM in real-time. The multilayer complex of M and CA was successfully formed on the crystal surface of the QCM when CA and M were introduced into the FIA-QCM system alternately. The influence of pH on the M and CA interaction indicated that the M-CA multilayer complex possesses high stability over a wide range of pH values, especially in physiological urine condition. The association and dissociation rate constants were determined under artificial urine condition and the association constant for M and CA was calculated as 10(2) L mol(-1). The M-CA complex was further characterized by Fourier transform infrared spectroscopy (FT-IR) and atomic force microscopy (AFM). Mechanism study suggested that the formation of the multilayer complex in artificial urine was mainly attributed to the intermolecular hydrogen bonding between M and CA. The work provides direct insight into the dynamic interaction between M and CA under physiological conditions and would be helpful for the research of kidney stones induced by melamine contamination.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Xie
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Huang
authors.forename: Weizhi
authors.initials: W
authors.lastname: Wang
authors.forename: Guoquan
authors.initials: G
authors.lastname: Liu
authors.forename: Rui
authors.initials: R
authors.lastname: Zhao
mesh_terms: D017022:Flow Injection Analysis; D006046:Gold / Q000737:chemistry; D006860:Hydrogen Bonding; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force / Q000379:methods; D058525:Quartz Crystal Microbalance Techniques / Q000379:methods*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014227:Triazines / Q000737:chemistry* / Q000652:urine
chemical_list: D014227:Triazines; D006046:Gold; C004632:cyanuric acid; C011907:melamine