scholarly journals Effects of Iron Concentration Level in Extracting Solutions from Contaminated Soils on the Determination of Zinc by Flame Atomic Absorption Spectrometry with Two Background Correctors

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Christophe Waterlot ◽  
Aurélie Pelfrêne ◽  
Francis Douay
Keyword(s):  
Contaminated Soils ◽  
High Speed ◽  
Iron Concentration ◽  
Absorption Spectrometry ◽  
Flame Atomic Absorption ◽  
Zinc Concentrations ◽  
Zinc Determination ◽  
Deuterium Lamp ◽  
The Continuum

Zinc and iron concentrations were determined after digestion, water, and three-step sequential extractions of contaminated soils. Analyses were carried out using flame absorption spectrometry with two background correctors: a deuterium lamp used as the continuum light source (D2method) and the high-speed self-reversal method (HSSR method). Regarding the preliminary results obtained with synthetic solutions, the D2method often emerged as an unsuitable configuration for compensating iron spectral interferences. In contrast, the HSSR method appeared as a convenient and powerful configuration and was tested for the determination of zinc in contaminated soils containing high amounts of iron. Simple, fast, and interference-free method, the HSSR method allows zinc determination at the ppb level in the presence of large amounts of iron with high stability, sensitivity, and reproducibility of results. Therefore, the HSSR method is described here as a promising approach for monitoring zinc concentrations in various iron-containing samples without any pretreatment.

Application of the high-speed self-reversal background corrector to the determination of cadmium by chemical vapor generation atomic absorption spectrometry

2012 ◽  
Vol 90 (10) ◽  
pp. 874-879 ◽  
Author(s):  
Christophe Waterlot ◽  
Aurélie Pelfrêne ◽  
Francis Douay
Keyword(s):  
Atomic Absorption Spectrometry ◽  
Atomic Absorption ◽  
Flame Atomic Absorption Spectrometry ◽  
High Speed ◽  
Absorption Spectrometry ◽  
Standard Reference Materials ◽  
Vapor Generation ◽  
Flame Atomic Absorption ◽  
Interference Problems

Concentrations of cadmium (Cd) in extracting solutions (neutral salts) from contaminated soils are often too low to be determined by conventional flame atomic absorption spectrometry. For this reason, determination of Cd requires sensitive analytical methods free from interference problems generated by samples. In this context, vapor generation atomic absorption spectrometry (HGAAS) was combined with a high-speed self-reversal background corrector. This new approach was successfully applied after optimization of the analytical parameters to obtain a maximal absorbance signal of the volatile Cd species. The optimum condition was achieved with a 3% (m/v) NaBH4 in 1.5% (m/v) NaOH reducing solution and a solution containing 0.3 mol/L HNO3. The detection limit was 1 ng mL–1 under the previous conditions and the relative standard deviation was up to 5% for 10 replicate analyses of Cd at 0.2 and 1 ng mL–1, reflecting a very highly sensitive and reproducible method. Moreover, the results showed that the proposed combination was an efficient method to overcome the interference problems caused by different coexisting cations, As, Al, Ca, Cu, Fe, Mg, Mn, Ni, Pb, Se and Zn, up to 10 µg mL–1. The method was validated with analyses of two standard reference materials and was used for Cd determination in 0.01 mol/L CaCl2 extracts from contaminated kitchen garden soils. The data were compared with those obtained by two other more conventional methods, electrothermal atomic absorption spectrometry (ETAAS) and flame atomic absorption spectrometry (FAAS). The analytical results obtained by the ETAAS and HGAAS were in a good agreement, suggesting the suitability of the method for Cd determination in 0.01 mol/L CaCl2 extracting solution.

scholarly journals Minimizing Chloride Interferences Produced by Calcium Chloride in the Determination of Cd by Graphite Furnace Atomic Absorption Spectrometry

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Christophe Waterlot ◽  
Francis Douay
Keyword(s):  
Atomic Absorption ◽  
High Speed ◽  
Graphite Furnace ◽  
Absorption Spectrometry ◽  
Chloride Ions ◽  
Background Correction ◽  
Chemical Modifier ◽  
Graphite Furnace Atomic Absorption ◽  
Deuterium Lamp

Cadmium concentrations in CaCl2 extracting solutions at various concentrations were determined by graphite furnace atomic absorption using two background correctors: the deuterium and the high-speed self-reversal background correction systems. Under- and overestimation of the Cd absorbance signals in CaCl2 solutions were observed for concentrations greater than 0.005 M using the deuterium lamp while no important effect was observed using the other background correction system. The analytical performance of the spectrometer for the determination of Cd was studied in 0.01 M CaCl2 solution and single extractions were performed using reference materials and contaminated soil samples. Cadmium was determined using the two background correction systems and a third method, which consists of the use of the deuterium lamp without any chemical modifier, was added to the study. The results showed that the third method was unable to determine Cd concentrations in the CaCl2 solution due to the presence of extractable arsenic and iron. For solutions without any dilution or diluted with a very low dilution factor, the CaCl2-extractable Cd concentrations measured using the deuterium lamp were systematically below those found using the high-speed self-reversal method. These differences were explained by the presence of chloride ions in the atomization step.

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