● AAS intrinsically more sensitive than AES ● Similar atomization techniques to AES ● Addition of radiation source ● High temperature for atomization necessary flame and electrothermal atomization ● Very high temperature for excitation not necessary generally no plasma / arc / spark AAS Atomic absorption spectrometry
● AAS intrinsically more sensitive than AES ● Similar atomization techniques to AES ● Addition of radiation source ● High temperature for atomization necessary flame and electrothermal atomization ● Very high temperature for excitation not necessary generally no plasma / arc / spark AAS Atomic absorption spectrometry
§8-2 Basic principle of AAS 1. Resonance line and absorption line E0 E1 E2 E3 A B Resonance emission line (simplified as resonance line): Electron, after absorbing electromagnetic radiation of the given frequency，is promoted from its ground state to the first excited state, a excited state with lowest energy, relevant absorption spectral line is called resonance absorption line.(使电子从基 态跃迁至第一 激发态所产生的吸收谱 线称为共振吸收线(简称为共振钱) )
§8-2 Basic principle of AAS 1. Resonance line and absorption line E0 E1 E2 E3 A B Resonance emission line (simplified as resonance line): Electron, after absorbing electromagnetic radiation of the given frequency，is promoted from its ground state to the first excited state, a excited state with lowest energy, relevant absorption spectral line is called resonance absorption line.(使电子从基 态跃迁至第一 激发态所产生的吸收谱 线称为共振吸收线(简称为共振钱) )
Resonance emission line (simplified as resonance line): The spectral line which electron emits when it directly returns (relax) form lowest electronic excited state to ground state is called resonance emission line which frequency equals that of electromagnetic radiation absorbed by electron when it is promoted from ground state to the first excited state. (电子从基 态跃迁到能量最低的激发态(称为第一激发态)时要吸收一定 频率的光，它再跃迁回基态时，则发射出同样频率的光(谱 线)，这 种谱线称为共振发射线(简称共振线)。)
Resonance emission line (simplified as resonance line): The spectral line which electron emits when it directly returns (relax) form lowest electronic excited state to ground state is called resonance emission line which frequency equals that of electromagnetic radiation absorbed by electron when it is promoted from ground state to the first excited state. (电子从基 态跃迁到能量最低的激发态(称为第一激发态)时要吸收一定 频率的光，它再跃迁回基态时，则发射出同样频率的光(谱 线)，这 种谱线称为共振发射线(简称共振线)。)
Characteristic spectral lines（特征谱线） Emphases For most atoms, resonance line is also sensitive line
Characteristic spectral lines（特征谱线） Emphases For most atoms, resonance line is also sensitive line
若将不同频率的光(强度为I0n )，) 通过原子蒸气(见右图)，有一部 分光将被吸收．其透过光的强 度(即原子吸收共振线后光的强 度)与原子蒸气的宽度(即火焰的 宽度)的关系，同有色溶液吸收 光的情况完全类似，遵循朗伯 定律，即： Atomic vapor I0n In L Schematic diagram of atomic absorption Where Kn is absorption coefficient of atomic vapor to the electromagnetic with a frequency of n 2. Line profile and line broadening In = I0n e -KnL (eq.8-1)
若将不同频率的光(强度为I0n )，) 通过原子蒸气(见右图)，有一部 分光将被吸收．其透过光的强 度(即原子吸收共振线后光的强 度)与原子蒸气的宽度(即火焰的 宽度)的关系，同有色溶液吸收 光的情况完全类似，遵循朗伯 定律，即： Atomic vapor I0n In L Schematic diagram of atomic absorption Where Kn is absorption coefficient of atomic vapor to the electromagnetic with a frequency of n 2. Line profile and line broadening In = I0n e -KnL (eq.8-1)