On-line precipitation–dissolution in knotted reactor for thermospray flame furnace AAS for determination of ultratrace cadmium

Abstract A simple, environmentally friendly, cost-effective and sensitive method was developed for the determination of trace cadmium in rice and water by using flow injection (FI) on-line precipitation–dissolution in a knotted reactor (KR) as a preconcentration scheme for thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS). The preconcentration was achieved by online merging the sample solution and the precipitating reagent in a KR and subsequently eluting the resultant precipitate of cadmium hydroxide with 1 mol/L HNO3. The eluant was then introduced into TS-FF-AAS for the determination. A self-assembled FI system was employed to hyphenate the KR system with TS-FF-AAS. Under optimal chemical and instrumental conditions, a limit of detection of 0.04 μg/L and a sensitivity enrichment factor of 34 for cadmium was obtained with a total initial sample volume of 4 mL. The proposed method was applied to the determination of cadmium in certified reference rice and water samples with analytical results in good agreement with their certified values. Real rice samples and real water samples were also determined by the proposed method, with analytical results confirmed by inductively coupled plasma mass spectroscopy (ICP-MS).

[1]  M. Arruda,et al.  A sensitive method for cadmium determination using an on-line polyurethane foam preconcentration system and thermospray flame furnace atomic absorption spectrometry. , 2004, Analytical sciences : the international journal of the Japan Society for Analytical Chemistry.

[2]  Z. Fang,et al.  Determination of cadmium in biological materials by flame atomic absorption spectrometry with flow-injection on-line sorption preconcentration. , 1994, Talanta.

[3]  X. Hou,et al.  Selective determination of trace amounts of silver in complicated matrices by displacement-cloud point extraction coupled with thermospray flame furnace atomic absorption spectrometry , 2008 .

[4]  Xiu‐Ping Yan,et al.  Investigation of on-line coupling electrothermal atomic absorption spectrometry with flow injection sorption preconcentration using a knotted reactor for totally automatic determination of lead in water samples , 1996 .

[5]  Xiu‐Ping Yan,et al.  Determination of trace cadmium in rice by flow injection on-line filterless precipitation-dissolution preconcentration coupled with flame atomic absorption spectrometry. , 2003, Journal of Agricultural and Food Chemistry.

[6]  Z. Fang,et al.  Octadecyl immobilized surface for precipitate collection with a renewable microcolumn in a lab-on-valve coupled to an electrothermal atomic absorption spectrometer for ultratrace cadmium determination. , 2005, Analytical chemistry.

[7]  M. Sperling,et al.  Flame atomic absorption spectrometric determination of lead in biological samples using a flow injection system with on-line preconcentration by coprecipitation without filtration , 1991 .

[8]  X. Hou,et al.  Cloud point extraction-thermospray flame quartz furnace atomic absorption spectrometry for determination of ultratrace cadmium in water and urine , 2006 .

[9]  X. Hou,et al.  Determination of trace cadmium and zinc in corn kernels and related soil samples by atomic absorption and chemical vapor generation atomic fluorescence after microwave-assisted digestion , 2006 .

[10]  M. Arruda,et al.  Determination of cadmium and lead at low levels by using preconcentration at fullerene coupled to thermospray flame furnace atomic absorption spectrometry , 2004 .

[11]  H. Berndt,et al.  Beam injection flame furnace atomic absorption spectrometry: a new flame method. , 2000, Analytical chemistry.

[12]  Liping Dong,et al.  Flow injection on-line coprecipitation preconcentration for electrothermal atomic absorption spectrometry , 1992 .

[13]  C. Tarley,et al.  Highly improved sensitivity of TS-FF-AAS for Cd(II) determination at ng L−1 levels using a simple flow injection minicolumn preconcentration system with multiwall carbon nanotubes , 2006 .

[14]  M. Arruda,et al.  Acid extraction and cloud point preconcentration as sample preparation strategies for cobalt determination in biological materials by thermospray flame furnace atomic absorption spectrometry , 2006 .

[15]  F. Adams,et al.  Determination of (ultra)trace amounts of antimony(III) in water by flow injection on-line sorption preconcentration in a knotted reactor coupled with electrothermal atomic absorption spectrometry , 1996 .

[16]  D. Beauchemin,et al.  Determination of trace metals in saline water using flow injection on-line precipitation coupled with inductively coupled plasma mass spectrometry , 2001 .

[17]  L. Martínez,et al.  Knotted Reactors and their Role in Flow‐Injection On‐line Preconcentration Systems Coupled to Atomic Spectrometry‐Based Detectors , 2005 .

[18]  Xiu‐Ping Yan,et al.  Flow injection on-line group preconcentration and separation of (ultra)trace rare earth elements in environmental and geological samples by precipitation using a knotted reactor as a filterless collector for inductively coupled plasma mass spectrometric determination , 1999 .

[19]  H. Berndt,et al.  Air driven on-line separation and preconcentration on a C18 column coupled with thermospray flame furnace AAS for the determination of cadmium and lead at μg l−1 levels , 2004 .

[20]  Xiu‐Ping Yan,et al.  Flow injection on-line preconcentration and separation coupled with atomic (mass) spectrometry for trace element (speciation) analysis based on sorption of organo-metallic complexes in a knotted reactor , 2001 .

[21]  X. Hou,et al.  Determination of Cadmium in Biological Samples , 2006 .

[22]  H. Berndt,et al.  Thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) — a simple method for trace element determination with microsamples in the μg/l concentration range , 2000 .

[23]  M. Arruda,et al.  Online Preconcentration/Determination of Cadmium Using Grape Bagasse in a Flow System Coupled to Thermospray Flame Furnace Atomic Absorption Spectrometry , 2006 .

[24]  H. Berndt,et al.  Improvements in thermospray flame furnace atomic absorption spectrometry , 2003 .