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Online Preconcentration and Determination of Trace Levels Cadmium in Water Samples Using Flow Injection Systems Coupled with Flame AAS
Author(s) -
Zhao Songlin,
Liang Huading,
Yan Hua,
Yan Zhengzhong,
Chen Suqing,
Zhu Xiandi,
Cheng Miaoxian
Publication year - 2010
Publication title -
clean – soil, air, water
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.444
H-Index - 66
eISSN - 1863-0669
pISSN - 1863-0650
DOI - 10.1002/clen.200900228
Subject(s) - chemistry , detection limit , calibration curve , cadmium , analytical chemistry (journal) , chromatography , certified reference materials , sorption , elution , correlation coefficient , atomic absorption spectroscopy , trace amounts , enrichment factor , volumetric flow rate , adsorption , medicine , statistics , physics , mathematics , alternative medicine , organic chemistry , quantum mechanics , pathology
A rapid and sensitive method for the determination of trace levels cadmium in water samples by flame atomic absorption spectrometry was developed. It is based on the online sorption of Cd(II) ions on a microcolumn packed with HCl treated bamboo charcoal. In a pH range of 5.0–7.5, Cd(II) ions were effectively retained on the microcolumn, which exhibited fast kinetics, permitting the use of high sample flow rates up to at least 12.8 mL/min without the loss of retention efficiency. The retained Cd(II) ions were quantitatively eluted with HCl (2.0 mol/L) for an online determination. With a preconcentration time of 80 s at a sample loading flow rate of 8.6 mL/min, a sensitivity enhancement factor of 63 was obtained compared with the slope of the linear portion of the calibration curves before and after preconcentration. The calibration graph using the preconcentration system for cadmium was linear with a correlation coefficient of 0.9997, at levels from 1–40 ng/mL. The precision (RSD) for 11 replicate measurements were 3.2% for the determination of 5 ng/mL Cd(II) and 1.8% for 20 ng/mL Cd(II), respectively, and the detection limit (3 s ) was 0.36 ng/mL. The accuracy was assessed through the determination of a certified reference material, and also through recovery experiments.