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

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• 作者：Xuefei Mao ; Jixin Liu ; Yatao Huang ; Li Feng ; Lihua Zhang ; Xiaoyan Tang ; Jian Zhou ; Yongzhong Qian ; Min Wang
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2013
• 出版时间：January 30, 2013
• 年：2013
• 卷：61
• 期：4
• 页码：848-853
• 全文大小：238K
• 年卷期：v.61,no.4(January 30, 2013)
• ISSN：1520-5118

文摘

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鈥?.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鈥?00 mg) of the methods of the Association of Official Analytical Chemists.

Keywords:

cadmium; rice; minimum sample mass; solid sampling; electrothermal vaporization atomic fluorescence spectrometry (ETV-AFS)