ABSTRACT
Bismuth modified boron doped diamond (BDD) film electrode was employed for simultaneous determination of trace ZnⅡ,CdⅡand PbⅡby anodic stripping voltammetry.BiⅢwas simultaneously in-situ deposited on bismuth modified boron doped diamond electrode with ZnⅡ,CdⅡ and PbⅡ by pre-concentration.In the presence of BiⅢ,the sensitivity for determination of ZnⅡ,CdⅡ and PbⅡ was remarkably enhanced.Influence factors such as bismuth concentration,boron doped concentrations of BDD electrode,pH,preconcentration potential were investigated and optimized.Under the optimal conditions,the stripping peak currents increased linearly with the increasing concentration of ZnⅡ,CdⅡ and PbⅡ in the range of 10-300 μg/L.The limit of detection was 0.56 μg/L for ZnⅡ,0.32 μg/L for CdⅡand 0.75 μg/L for PbⅡ (S/N=3),respectively.The interference experiments showed that common ions had little influence on the determination except CuⅡ.In addition,the developed electrode displayed a good repeatability.The method was successfully applied to determination of ZnⅡ,CdⅡ and PbⅡ in real water samples with the standard addition recoveries of 92.0%-114.0%.
ABSTRACT
A novel electrochemical method based on dehydroabietylamine schiff base( DBS) and multi-walled carbon nano-tubes( MWCNTs) composite modified glassy carbon electrode was presented for determination of Pb2+. The electrochemical behaviors of Pb2+on the modifled electrode were investigated by cyclic voltammetry ( CV) and differential pulse anodic stripping voltammetry ( DPASV ) . The results showed that under the optimized conditions including 0 . 2 mol/L NaAc-HAc used as supporting buffer ( pH 5 . 5 ) , -1 . 1 V of accumulating potential, 250 s of accumulating time, the oxidation peak current was proportional to Pb2+concentration in the range between 1 × 10-8 mol/L and 1 × 10-6 mol/L with the linear regression equation as I(μA)= 6. 6173c(μmol/L)+0. 2597(R=0. 9971) and the detection limit as 5. 0×10-9 mol/L (S/N=3). The proposed sensor was successfully employed to determine Pb2+ in real samples with satisfactory results. In addition, this method showed the advantages of simple operation, short assay time, good accuracy, satisfactory efficiency and good selectivity for determination of low concentration lead in water samples.
ABSTRACT
A method of detecting lead was developed using square wave anodic stripping voltammetry (SWASV) with DNA-carbon nanotube paste electrode (CNTPE). The results indicated a sensitive oxidation peak current of lead on the DNA-CNTPE. The curves were obtained within a concentration range of 50 ngL-1-20 mgL-1 with preconcentration time of 100, 200, and 400 sec at the concentration of mgL-1, microgL-1, and ngL-1, respectively. The observed relative standard deviation was 0.101% (n = 12) in the lead concentration of 30.0 microgL-1 under optimum conditions. The low detection limit (S/N) was pegged at 8 ngL-1 (2.6 x10-8 M). Results showed that the developed method can be used in real-time assay in vivo without requiring any pretreatment and pharmaceutical samples, and food samples, as well as other materials requiring water source contamination analyses.
Subject(s)
Electrodes , Limit of Detection , Nanotubes , Plants , WaterABSTRACT
Objective To establish a new method for determination of Pb and Cd in sewage.Methods The contents of Pb and Cd in sewage were simultaneously determined by linear sweep anodic stripping voltammetry in0.1mol/L HCl -0.1mol/L KCl solution.Results The peak potentials of Pb and Cd appeared at-588mV and-780mV respectively.The recovery rates and precisions(RSD%)of Pb and Cd were90.0%-110.0%,91%-109.5%and0.41%-4.24%,0.56%-7.03%respectively.The lin-ear range of Pb and Cd was0.005-0.2mg /L.Conclusion This method could be applied for determination of Pb and Cd in sewage.
ABSTRACT
Simultaneous determination of zinc, cadmium, tin, lead and copper was studied in 0.2-0.3M hydrochloric acid-methanol by 1.5 grade differential anodic stripping voltammetry. A stick silver base mercurial film electrode was used as a working electrode. The peak potential of Zn, Cd, Sn, Pb and Cu was distinctly separated each other being -1.05V, -0.74V -0.55V, -0.44V and -0.25V vs SCE, respectivly, in the above solvent electrolyte.Calibration curves of Cd, Sn, Pb and Cu in range of 20 to 600 ng/ml and Zn in range of 0.2 to 4 ug/ml showed linear relation. Canned foods could be analyzed, by dilution with the supporting electrolyte after digestion of the samples with mixed acid. The juice samples could be analyzed directly without digestion, by simple 5-2000 times dilution with the supporting electrolyte. Coefficient of variation and recovey was 6.7-8.0% and 91.2-107% respectively.