原子吸收光谱法(AAS)是研究气相中孤立原子在紫外或电磁光谱可见区域内吸收辐射能的一种方法。考虑到在原子吸收光谱中，被分析物作为自由原子被引入仪器的光束中，所有可能的旋转和振动能级都是简并的(具有相同的能量)。与多元化学物种的吸收光谱(离子或分子)通常会有多种可行的转换对应几个转动和振动能级上不同的电子能级,自由原子的光谱特征是仅仅是一个合理的很少有锋利的吸光度(光谱行)通常与电子能级的变化。多原子物质所能达到的多种可能的不同能级导致了几乎连续的可能跃迁。因此，离子(分子)的光谱由一些较宽的波段组成，这些波段是由几个独立跃迁的部分分辨率引起的。因此，原子光谱的一个特点是与多原子物种的光谱相比，它们很简单。
新西兰生物学代写作业:电磁光谱
Atomic Absorption Spectroscopy (AAS) relates to the study of the absorption of radiant energy commonly within the ultraviolet or possibly in the visible region of the electromagnetic spectrum by isolated atoms in the gaseous phase. Considering that, in Atomic Absorption Spectroscopy, the analyte is introduced to the optical beam of the instrument as free atoms, all the likely rotational and vibrational energy levels are degenerate (of the same energy). Contrary to the absorption spectra of polyatomic chemical species (ions or molecules) in which there is often a multiplicity of feasible transitions corresponding to several rotational and vibrational energy levels superimposed on distinct electronic energy levels, the spectra of free atoms are characterized by merely a reasonably very few sharp absorbances (line spectra) which are often correlated with changes in electronic energy levels. The multitude of possible different energy levels accessible to polyatomic species leads to almost a continuum of possible transitions. As a result the spectra of ions (molecules) are comprised of somewhat broad bands which are caused by the partial resolution of several individual transitions. Hence, one feature of atomic spectra is their simpleness compared to the spectra of polyatomic species.
