Measurement of Arsenic and Selenium in White Rice and River Water by Hydride Generation-Atomic Absorption Spectrometry (HG-AAS) with Electric Cell Heating

Introduction

The hydride generation method is known as a technique for high-sensitivity measurement of elements such as arsenic (As) and selenium (Se), based on the fact that at ambient temperature such elements react with newly generated active hydrogen to generate hydrogen gas compounds. Because it is not easy affected by alkaline metals, alkaline earth metals, and other elements coexisting in samples, it is often used for high-sensitivity measurement of As, Se, and other elements in the environment, foods, and other samples, not only in atomic absorption spectrometry, but also in ICP atomic emission spectrometry, ICP mass spectrometry, and other methods. The method commonly used for atomic absorption spectrometry involves sending the hydrogen compound gas (AsH₃ and H₂Se) generated in a hydride vapor generator into a quartz absorption cell and atomizing the elements by thermal decomposition. Then either a flame or electric heating (furnace) is used to heat the absorption cell. Electric heating avoids the need for gas supplies required for the flame method (acetylene and air) and offers about 1.5 times higher sensitivity than the flame method for As and Se measurements. In this example, hydride generation-atomic absorption spectrometry (HG-AAS) with an electric cell heater for heating the absorption cell was used to measure arsenic and selenium in certified white rice reference material (NMIJ CRM 7502-a) and certified river water reference materials (JSAC 0301 with nothing added and JSAC 0302 with As and Se added).

October 6, 2015 GMT