title: Determination of copper (II) in foodstuffs based on its quenching effect on the fluorescence of N,N'-bis(pyridoxal phosphate)-o-phenylenediamine.
abstract: A Schiff base-type fluorescence probe was prepared for the detection of copper (II) in foodstuffs. The probe is N,N'-bis(pyridoxal phosphate)-o-phenylenediamine (BPPP). It was synthesized by utilizing the Schiff base condensation reaction of pyridoxal 5-phosphate with 1,2-phenylenediamine. BPPP has the properties of high fluorescence stability, good water solubility and low toxicity. Its maximum excitation wavelength and maximum fluorescence emission wavelength are at 389 and 448 nm, respectively. When BPPP coexists with copper (II), its fluorescence is dramatically quenched. Under a certain condition, the fluorescence intensity decreased proportionally to the concentration of copper (II) by the quenching effect. Based on this fact, we established a fluorescence quenching method for the determination of copper (II). Under optimal conditions a linear range was found to be 0.5-50 ng/mL with a detection limit of 0.2 ng/mL. The method has been applied to determine copper (II) in foodstuff samples and the analytical results show good agreement with that obtained from atomic absorption spectrometry method.
authors.affiliation: College of Chemistry and Chemical Engineering, University of South China, Hengyang, Hunan 421001, China.
authors.forename: Canhui
authors.initials: C
authors.lastname: Xu
authors.affiliation: College of Chemistry and Chemical Engineering, University of South China, Hengyang, Hunan 421001, China. Electronic address: llfcxllc@163.com.
authors.forename: Lifu
authors.initials: L
authors.lastname: Liao
authors.affiliation: College of Chemistry and Chemical Engineering, University of South China, Hengyang, Hunan 421001, China.
authors.forename: Yunfei
authors.initials: Y
authors.lastname: He
authors.affiliation: College of Chemistry and Chemical Engineering, University of South China, Hengyang, Hunan 421001, China.
authors.forename: Rurong
authors.initials: R
authors.lastname: Wu
authors.affiliation: College of Chemistry and Chemical Engineering, University of South China, Hengyang, Hunan 421001, China.
authors.forename: Shijun
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Chemistry and Chemical Engineering, University of South China, Hengyang, Hunan 421001, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Yang
mesh_terms: D002138:Calibration; D003300:Copper / Q000032:analysis*; D005504:Food Analysis; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives* / Q000737:chemistry*; D012996:Solutions; D013050:Spectrometry, Fluorescence; D013997:Time Factors
chemical_list: C000610467:N,N'-bis(pyridoxal phosphate)-o-phenylenediamine; D012996:Solutions; D011732:Pyridoxal Phosphate; D003300:Copper
keywords: Copper (II); Fluorescence; Foodstuff; N,N′-bis(pyridoxal phosphate)-o-phenylenediamine; Quenching