title: Preconcentration of trace arsenite and arsenate with titanium dioxide nanoparticles and subsequent determination by silver diethyldithiocarbamate spectrophotometric method.
abstract: A novel method of preconcentration of trace arsenite and arsenate by using titanium dioxide nanoparticles as adsorbent was described. The concentrations of preconcentrated arsenite and arsenate were determined by a silver diethyldithiocarbamate spectrophotometric method without desorption. Batch adsorption experiments were carried out as a function of the pH, contact time, amount of titanium dioxide nanoparticles, and solution volume. In the pH range 5 to 6, adsorption rates of arsenite and arsenate were higher than 98%. The calibration coefficient was 0.9991, and the linear range was 0 to 100 microg/L. The developed method was precise, with the relative standard deviation <5% at concentration level of 10 microg/L, with a detection limit (3sigma, n=6) of 0.44 microg/L. The accuracy of the method for total arsenic was validated by standard reference materials (SRM 3103a) (National Institute of Standards and Technology, Gaithersburg, Maryland). The method was also applied to the analysis of arsenite and arsenate in natural water samples to verify the accuracy. The recovery values remained in a narrow range, from 95 to 103%.
authors.affiliation: Tianjin Enter-Exit Inspection and Quarantine Bureau, Tianjin, China.
authors.forename: Yabing
authors.initials: Y
authors.lastname: Xiao
authors.forename: Jie
authors.initials: J
authors.lastname: Ling
authors.forename: Shahua
authors.initials: S
authors.lastname: Qian
authors.forename: Anqing
authors.initials: A
authors.lastname: Lin
authors.forename: Wenjie
authors.initials: W
authors.lastname: Zheng
authors.forename: Weiya
authors.initials: W
authors.lastname: Xu
authors.forename: Yuxuan
authors.initials: Y
authors.lastname: Luo
authors.forename: Man
authors.initials: M
authors.lastname: Zhang
mesh_terms: D000042:Absorption; D001149:Arsenates / Q000032:analysis*; D018053:Arsenites / Q000032:analysis*; D002138:Calibration; D004050:Ditiocarb / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry; D012680:Sensitivity and Specificity; D012996:Solutions / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014025:Titanium / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis*
chemical_list: D001149:Arsenates; D018053:Arsenites; D012996:Solutions; D014874:Water Pollutants, Chemical; C001924:silver diethyldithiocarbamate; C009495:titanium dioxide; D004050:Ditiocarb; D014025:Titanium; C015001:arsenite; C025657:arsenic acid