Simultaneous Determination of Cd and Fe in Beans and Soil of Different Regions of Brazil Using High-Resolution Continuum Source Graphite Furnace Atomic Absorption Spectrometry and Direct Solid Sampling

Abstract

A fast routine screening method for the simultaneous determination of cadmium and iron in bean and soil samples is proposed, using high-resolution continuum source graphite furnace atomic absorption spectrometry and direct solid sampling. The primary absorption line at 228.802 nm has been used for the determination of cadmium, and an adjacent secondary line, at 228.726 nm, for iron. Fourteen bean samples and 10 soil samples from nine states all over Brazil have been analyzed. The limits of detection (3 sigma, n = 10) were 2.0 microg kg(-1) for Cd and 4.5 mg kg(-1) for Fe. The relative standard deviation ranged from 4 to 7% for Cd and from 5 to 28% for Fe, which is usually acceptable for a screening method. The accuracy of the method has been confirmed by the analysis of two certified reference materials; the results were in agreement with the certified values at a 95% confidence interval.

Unusual calibration curves observed for iron using high-resolution continuum source graphite furnace atomic absorption spectrometry

“…The original idea of this work has been to transfer the procedure that has been developed for the simultaneous determination of Cd and Fe in grain products using direct solid sampling [9] to the analysis of bean and soil samples from different regions of Brazil [7]. While the procedure worked well for the bean samples, the soil samples turned out to be a problem due to their extremely high iron content.…”

“…In order to coat the platform with the W-Ir mixed permanent modifier, five aliquots of 40 µL of the W modifier solution were applied first, each one followed by the temperature program shown in Ref. [7,9], then five aliquots of 40 µL of the Ir modifier solution were applied, also followed by the same temperature program, resulting in a coating with 200 µg each of W and Ir.…”

“…On the other hand, HR-CS AAS is offering possibilities to extend the linear working range, the most attractive one being measurement of the absorbance at the wings of the analytical line [5]; this option, however, has only been used in a few cases [6,7] and has not yet been explored systematically for the analysis of real samples. Another possibility to cope with high analyte concentrations is the measurement at secondary, less sensitive analytical lines.…”

“…This way it has for example been possible to extend the working range for the determination of nickel in crude oil to more than three orders of magnitude by simultaneous determination at the primary resonance line at 232.003 nm and a secondary line at 232.138 nm [8]. The simultaneous determination of more than one analyte has been demonstrated for the determination of Cd and Fe in grain products [9] and in bean and soil samples [7], for Co and V [6] and Cr and Fe in crude oil [10].…”

Application of a new version of GA-RBF neural network for simultaneous spectrophotometric determination of Zn(II), Fe(II), Co(II) and Cu(II) in real samples: An exploratory study of their complexation abilities toward MTB

“…Therefore, there is a growing interest in developing reliable sensitive quantitative methodologies for the determination of the amount of micro minerals in various real samples. The most common methods for the determination of Zn 2+ , Fe 2+ , Co 2+ and Cu 2+ simultaneously or in combination with other micro minerals in pharmaceutical product and various vegetable samples are flame atomic absorption spectroscopy (FAAS) [8,9], graphite furnace atomic absorption spectrometry (GF-AAS) [10], inductively coupled plasma-mass spectrometry (ICP-MS) [11,12], inductively coupled plasma-atomic emission spectrometry (ICP-AES) [13,14], electrochemical methods [15][16] and ion chromatography [17]. However, some of the aforementioned methods employ expensive instruments and/or material, high purity solvents and often pretreatment steps of samples are required.…”