title: Solid phase extraction and spectrophotometric determination of silver with 2-(2-quinolylazo)-5-diethylaminophenol as chromogenic reagent.
abstract: A new chromogenic reagent, 2-(2-quinolylazo)-5-diethylaminophenol (QADEAP), was synthesized. A sensitive, selective and rapid method has been developed for the determination of microg/L level silver ion based on the rapid reaction of silver(l) with QADEAP and the solid phase extraction of the colored chelate with C18 cartridge. The QADEAP reacts with Ag(l) to form a violet chelate of a molar ratio 1:2 (silver to QADEAP) in pH 3.5-8.0. This chelate was prconcentrated by solid phase extraction with C18 cartridge. An enrichment factor of 100 was achieved. The molar absorptivity of the chelate is 1.30 x 10(5) L mol(-1) cm(-1) at 590 nm in measured solution. Beer's law is obeyed in the range of 0.01-0.6 microg/ml. The relative standard deviation for eleven replicate samples of 0.01 microg/ml is 1.15%. The detection limit is 0.02 microg/L in the original samples. This method was applied to the determination of microg/L level silver ion in water with good results.
authors.affiliation: Department of Chemistry, Yunnan University, Kunming 650091, P. R. China.
authors.forename: Guangyu
authors.initials: G
authors.lastname: Yang
authors.forename: Qiufen
authors.initials: Q
authors.lastname: Hu
authors.forename: Jihong
authors.initials: J
authors.lastname: Yang
authors.forename: Zhangjie
authors.initials: Z
authors.lastname: Huang
authors.forename: Jiayuan
authors.initials: J
authors.lastname: Yin
mesh_terms: D000627:Aminophenols / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D002138:Calibration; D002863:Chromogenic Compounds / Q000737:chemistry*; D005618:Fresh Water / Q000032:analysis; D015386:Hazardous Substances / Q000032:analysis / Q000302:isolation & purification; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012834:Silver / Q000032:analysis / Q000302:isolation & purification*; D013057:Spectrum Analysis / Q000592:standards
chemical_list: C475893:2-(2-quinolylazo)-5-diethylaminophenol; D000627:Aminophenols; D001391:Azo Compounds; D002863:Chromogenic Compounds; D015386:Hazardous Substances; D012834:Silver