An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon paste electrode (CPE) has been developed. Pb2+ and Cd2+ were accumulated at the surface of ...An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon paste electrode (CPE) has been developed. Pb2+ and Cd2+ were accumulated at the surface of the modified electrode via formation of chemical complexes with calix[6]arene, and reduced at 1.40 V. During the following anodic potential sweep, reduced lead and cadmium were oxidized, and two well-defined striping peaks appeared at about ?0.60 V and ?0.84 V. Compared with a bare carbon paste electrode, the calix[6]arene modified CPE greatly improves the sensitivity of determining lead and cadmium. The stripping peak currents change linearly with the concentration of Pb2+ 3.0×10?8–8.0×10?6 mol·L?1 and with that of Cd2+ 6.0×10?8–1.0×10?5 mol ·L?1. The detection limits of Pb2+ and Cd2+ are found to be 8.0×10?9 mol·L?1 and 2.0×10?8 mol·L?1, respectively. The modified carbon paste electrode was applied to determine trace levels of lead and cadmium in water samples. Comparing with that of atomic absorption spectrometry, the results suggests that the calix[6]arene modified CPE has great potential for the practical sample analysis. Key words lead(II) - cadmium(II) - calix[6]arene - differential pulse stripping voltammetry - chemically modified electrode CLC number O 657.15 Foundation item: Supported by the National Natural Science Foundation of China (60171023)Biography: JI Xiao-bo (1980-), male, Master, research direction: electroanalytical chemistry.展开更多
A novel fluorescent probe,6-（N,N-dimethylamino）-2-naphthoylacryl acid（ACADAN） was designed and synthesized as a fluorescent sensor for Cu^2＋ in aqueous media.Significant amplification of fluorescence signals with...A novel fluorescent probe,6-（N,N-dimethylamino）-2-naphthoylacryl acid（ACADAN） was designed and synthesized as a fluorescent sensor for Cu^2＋ in aqueous media.Significant amplification of fluorescence signals without causing any discernible change of maximum fluorescence emission wavelength（λ max） was observed upon the addition of Cu^2＋.Importantly,ACADAN is capable of recognizing Cu^2＋ selectively in aqueous media in the presence of various biologically relevant metal ions and the prevalent toxic metal ions in the environment with high sensitivity（detection limit was 0.1 μmol/L）.展开更多
文摘An electrochemical method for the simultaneous determination of lead(II) and Cadmium(II) with a calix[6]arene modified carbon paste electrode (CPE) has been developed. Pb2+ and Cd2+ were accumulated at the surface of the modified electrode via formation of chemical complexes with calix[6]arene, and reduced at 1.40 V. During the following anodic potential sweep, reduced lead and cadmium were oxidized, and two well-defined striping peaks appeared at about ?0.60 V and ?0.84 V. Compared with a bare carbon paste electrode, the calix[6]arene modified CPE greatly improves the sensitivity of determining lead and cadmium. The stripping peak currents change linearly with the concentration of Pb2+ 3.0×10?8–8.0×10?6 mol·L?1 and with that of Cd2+ 6.0×10?8–1.0×10?5 mol ·L?1. The detection limits of Pb2+ and Cd2+ are found to be 8.0×10?9 mol·L?1 and 2.0×10?8 mol·L?1, respectively. The modified carbon paste electrode was applied to determine trace levels of lead and cadmium in water samples. Comparing with that of atomic absorption spectrometry, the results suggests that the calix[6]arene modified CPE has great potential for the practical sample analysis. Key words lead(II) - cadmium(II) - calix[6]arene - differential pulse stripping voltammetry - chemically modified electrode CLC number O 657.15 Foundation item: Supported by the National Natural Science Foundation of China (60171023)Biography: JI Xiao-bo (1980-), male, Master, research direction: electroanalytical chemistry.
基金Supported by the National Natural Science Foundation of China(Nos.30672560,81172982)the Accented Project for Natural Scientific Research of Universities in Guangdong Province,China(No.05Z012)
文摘A novel fluorescent probe,6-（N,N-dimethylamino）-2-naphthoylacryl acid（ACADAN） was designed and synthesized as a fluorescent sensor for Cu^2＋ in aqueous media.Significant amplification of fluorescence signals without causing any discernible change of maximum fluorescence emission wavelength（λ max） was observed upon the addition of Cu^2＋.Importantly,ACADAN is capable of recognizing Cu^2＋ selectively in aqueous media in the presence of various biologically relevant metal ions and the prevalent toxic metal ions in the environment with high sensitivity（detection limit was 0.1 μmol/L）.
