摘要:

The polarographic waves of lead (II) and tin (II) overlap due to their similar reductive potentials and it is difficult to determine these two components simultaneously without a pre-separation. In this paper, differential pulse polarography (DPP) combined with multivariate calibration approaches, such as classical least squares (CLS), principal component regression (PCR) and partial least squares (PLS), were successfully applied to the resolution of overlapping polarographic waves of these two components in the concentration range of 0.05-3.50 mg 1−1. Satisfactory quantitative results were obtained.

ISSN:0003-2719    

DOI:10.1080/00032719908542954

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

An on-line preconcentration method, based on complex formation with ammonium diethyldithiphosphate (DDTP-NH4) and sorption on a C18-bonded silica reversed phase sorbent, for the determination of Pb, Cd and Cu in potable water and biological samples was investigated. Preconcentration factors of 25; 38 and 86 and detection limits of 7, 3" acceptdate="and 7 μg/L for Pb, Cd and Cu, respectively, were obtained, with sample throughputs of 26, 38" acceptdate="and 29 samples/h. The system was efficient at low pH ranges and good agreement between found and certified values was observed in the analysis of certified reference materials.

ISSN:0003-2719    

DOI:10.1080/00032719908542955

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A combined system of flow injection/hydride generation coupled with multichannel plasma spectrometer was put forward and applied to the simultaneous determination of trace arsenic and mercury. The interface between flow injection hydride generation (FI-HG) and ICP-AES, gas/liquid separator and main experimental parameters were described. The detection limits of the proposed method could be achieved to 0.x μg/L level; The RSD 1.4% and 1.3% at 10 ng/mL levels of As and Hg respectively. The frequency of sampling was 150/h with 80μL sampling volume. The proposed method has been applied to the simultaneous determination of As and Hg in some real samples.

ISSN:0003-2719    

DOI:10.1080/00032719908542956

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A flow injection catalytic method is proposed for determination of trace vanadium based on its catalytic action on a new indicator reaction between Victoria blue B (VBB) and potassium bromate in the presence of citric acid as an activator and in dilute sulfuric acid medium. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of VBB injected at the maximum absorption wavelength of 618 nm. The detection limit is 0.5 ng ml−1and is independent of the initial valence state of vanadium. The relative standard deviation is 1.5% obtained from 11 standard solutions each containing 40 ng ml−1of vanadium. The sampling rate is about 15 samples per hour. This method is very simple and has been applied to the determination of trace vanadium in some natural waters with recoveries of 93-103%.

ISSN:0003-2719    

DOI:10.1080/00032719908542957

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor

摘要:

A catalytic quenching spectrofluorimetric method for the determination of V(V) using azomethine-H as a luminescence reagent has been investigated due to the catalytic effect of V(V) ion on oxidation of azomethine-H by potassium bromate at pH 4.2 and 30 °C. The reaction was monitored spectrofluorimetrically by measuring the decrease of fluorescence intensity of azomethine-H (λex=382nm, λem=422nm) after a fixed time (4 min) and used EDTA to stop the reaction. The fluorescence decrease varies linearly with the concentration of vanadium(V) in the range 5.0 x 10−1-0.022 μg mL−1(SD=0.00029 for 10 times measurements), and 0.025-0.060 μg mL−1(SD=0.00038 for 15 times measurements), respectively. The detection limit of the method was down to 6.914 x 10-5 μg mL−1. The effect of foreign ions was studied and the method was found free from interference except Fe3+. The proposed method was successively applied to determine vanadium(V) in natural water.

ISSN:0003-2719    

DOI:10.1080/00032719908542958

出版商:Taylor & Francis Group    

年代:1999

数据来源: Taylor