附件37 2.2.23 原子吸收色谱.doc

01/2008:20223 2.2.23. Atomic absorption spectrometry 原子吸收色谱法 general principle 原理 ?Atomic absorption is a process that occurs when a ground state-atom absorbs electromagnetic radiation of a specific wavelength and is elevated to an excited state. The atoms in the ground state absorb energy at their resonant frequency and the electromagnetic radiation is attenuated due to resonance absorption. The energy absorption is virtually a direct function of the number of atoms present. 当基态原子吸收特征谱线时跃迁为激发态。基态原子以其共振频率吸收能量，且该共振吸收会引起电磁辐射的衰减。能量吸收实际上是所存在数量的原子的直接功能的体现。 This chapter provides general information and defines the procedures used in element determinations by atomic absorption spectrometry, either atomisation by flame, by electrothermal vaporisation in a graphite furnace, by hydride generation or by cold vapour technique for mercury. 本章提供了原子吸收的总体信息，给出了元素测定的操作过程，包括通过火焰原子化，石墨炉电热蒸发原子化，氢化物发生器原子化或者汞冷蒸气原子化。 Atomic absorption spectrometry is a technique for determining the concentration of an element in a sample by measuring the absorption of electromagnetic radiation by the atomic vapour of the element generated from the sample. The determination is carried out at the wavelength of one of the absorption (resonance) lines of the element concerned. The amount of radiation absorbed is, according to the Lambert-Beer law, proportional to the element concentration. 原子吸收光谱是一项测量样品中所含的某种元素浓度的技术，它通过测量样品中该元素原子蒸气的辐射光吸收来实现的，通过选择待测元素的其中一条吸收谱带（共振）进行测量。根据朗伯比尔定律，所吸收的辐射的量与元素浓度成一定比例。 apparatus 仪器 This consists essentially of: 基本组成如下： —??a source of radiation; —??a sample introduction device; —??a sample atomiser; —??a monochromator or polychromator; —??a detector; a data-acquisition?unit. 光源 进样装置 样品原子化器 单色器或多色仪 检测器 数据采集系统 The apparatus is usually equipped with a background correction system. Hollow-cathode lamps and electrodeless discharge lamps (EDL) are used as radiation source. The emission of such lamps consists of a spectrum showing very narrow lines with half-width of about 0.002?nm of the