Assessment of Homogeneity and Minimum Sample Mass for Cadmium Analysis in Powdered Certified Reference Materials and Real Rice Samples by Solid Sampling Electrothermal Vaporization Atomic Fluorescence Spectrometry

Abstract

To optimize analytical quality controls of solid sampling electrothermal vaporization atomic fluorescence spectrometry (SS-ETV-AFS), the homogeneity (H(E)) of rice samples and their minimum sample mass (M) for cadmium analysis were evaluated using three certified reference materials (CRMs) and real rice samples. The effects of different grinding degrees (particle sizes <0.85, <0.25, <0.15, and >1 mm) on H(E) and M of real rice samples were also investigated. The calculated M values of three CRMs by the Pauwels equation were 2.19, 19.76, and 3.79 mg. The well-ground real rice samples (particle size <0.25 mm) demonstrated good homogeneity, and the M values were 3.48-4.27 mg. On the basis of these results, the Cd concentrations measured by the proposed method were compared with the results by microwave digestion graphite furnace atomic absorption spectrometry with a 0.5 g sample mass. There was no significant difference between these two methods, which meant that SS-ETV-AFS could be used to accurately detect Cd in rice with several milligrams of samples instead of the certified value (200 mg) or the recommended mass (200-500 mg) of the methods of the Association of Official Analytical Chemists.

Efficient generation of volatile species for cadmium analysis in seafood and rice samples by a modified chemical vapor generation system coupled with atomic fluorescence spectrometry

“…Generally, the combination of chemical vapor generation (CVG) with a specific and sensitive detector including atomic absorption spectroscopy (AAS) [2][3][4], atomic fluorescence spectrometry (AFS) [5][6][7], and inductively coupled plasma mass spectrometry (ICP-MS) [8,9] has been considered as an efficient approach for determination of Cd. The volatile cadmium species can be generated by using the reaction of Cd(II) and sodium borohydride (NaBH 4 ).…”

Direct determination of cadmium in geological samples by slurry sampling electrothermal atomic absorption spectrometry

“…The assessment of cadmium (Cd) in the environment or geological samples is important in the study of environmental pollution because of the toxic effect of Cd on human health and the fact that Cd-contaminated crops can grow from polluted soil. [1][2][3] The abundance of Cd in the upper continental crust is only 0.09 mg g À1 . Therefore, the concentration of Cd is at trace or ultra-trace levels in natural soils, sediments, and rocks (except for Cd mineral deposits).…”

Analytical Methodologies for Agrometallomics: A Critical Review

“…or milligram level, e.g., direct solid analysis of ETV-ICP-OES using ∼2 mg of sample was developed for the determination of both macro (Al, Ca, Fe, Mg, S) and trace (Ag, As, Au, Ba, Cd, Ce, Co, Cr, Cs, Cu, Dy, Eu, Ga, Hf, Hg, Ho, In, K, La, Mn, Mo, Na, Nd, Ni, P, Pb, Rb, Sb, Sc, Se, Si, Sm, Sr, Ti, U, V, W, Yb, Zn, Zr) elements existing in avian bone and slag samples;233 Mao et al230 used ETV-AFS to analyze submilligram powdered rice sample to evaluate the Cd distribution and homogeneity for different sample preparations. Of course, if ETV is coupled with ICP-TOF-MS,234−236 ICP-SF-MS,237−239 or MC-ICP-MS,…”