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原子發(fā)射光譜儀(AES)，是利用原子或離子在一定條件下受激而發(fā)射的特征光譜來研究物質(zhì)化學(xué)組成的分析方法。根據(jù)激發(fā)機(jī)理不同，原子發(fā)射光譜有3種類型：①原子的核外光學(xué)電子在受熱能和電能激
Atomic emission spectrometry (AES) is an analytical method to study the chemical composition of the material by using the characteristic spectrum of atom or ion under certain conditions. According to the different excitation mechanism, there are 3 types of atomic emission spectra: the nuclear external optical electrons in the atom and the
發(fā)而發(fā)射的光譜，通常所稱的原子發(fā)射光譜法是指以電弧、電火花和電火焰(如ICP等)為激發(fā)光源來得到原子光譜的分析方法。以化學(xué)火焰為激發(fā)光源來得到原子發(fā)射光譜的，專稱為火焰光度法。②原子核外光學(xué)電子受到光能激發(fā)而發(fā)射的光譜，稱為原子熒光(見原子熒光光譜分析)。③原子受到X射線光子或其他微觀粒子激發(fā)使內(nèi)層電子電離而出現(xiàn)空穴，較外層的電子躍遷到空穴，同時產(chǎn)生次級X射線即X射線熒光(見X射線熒光光譜分析)。在通常的情況下，原子處于基態(tài)。基態(tài)原子受到激發(fā)躍遷到能量較高的激發(fā)態(tài)。激發(fā)態(tài)原子是不穩(wěn)定的，平均壽命為10-10～10-8秒。隨后激發(fā)原子就要躍遷回到低能態(tài)或基態(tài)，同時釋放出多余的能量，如果以輻射的形式釋放能量，該能量就是釋放光子的能量。因為原子核外電子能量是量子化的，因此伴隨電子躍遷而釋放的光子能量就等于電子發(fā)生躍遷的兩能級的能量差 ，式中h為普朗克常數(shù);c為光速;ν和λ分別為發(fā)射譜線的特征頻率和特征波長。
The atomic emission spectrometry, commonly referred to as the atomic emission spectrometry, is an analytical method to obtain atomic spectra by means of arc, electric spark, and electric flame (e.g., ICP, etc.). The flame is used as the excitation source to get the atomic emission spectrum, which is called the flame photometric method. Atomic fluorescence spectroscopy, atomic fluorescence spectrometry, atomic fluorescence (see atomic fluorescence spectrometry). The atoms are X ray photons or other micro particle excitation to the inner electron ionization and a hole, the outer layer of the electronic transitions into the hole, at the same time to produce secondary X ray or X ray fluorescence (see X - ray fluorescence analysis). In the usual case, atoms are in the ground state. The ground state atom is excited by the excited transition to the higher energy. Excited state atoms are unstable, the average life expectancy of 10-10 ~ 10-8 seconds. Then the excited atom is going to jump back to the low energy state or the ground state, and at the same time release the excess energy. If the energy is released in the form of radiation, the energy is released by the energy of the photon. Because the atom energy is quantized, so with the electronic transitions and the photon energy release is equal to the electronic transitions of the two level energy difference, h for the Planck constant; C light; V and lambda respectively transmit characteristic frequency and characteristic wavelength spectrum.
根據(jù)譜線的特征頻率和特征波長可以進(jìn)行定性分析。常用的光譜定性分析方法有鐵光譜比較法和標(biāo)準(zhǔn)試樣光譜比較法。
According to the characteristic frequency and the characteristic wavelength of the spectral line can be analyzed qualitatively. Comparison of analytical methods for spectral analysis and standard sample spectra comparison.
原子發(fā)射光譜的譜線強度I與試樣中被測組分的濃度c成正比。據(jù)此可以進(jìn)行光譜定量分析。光譜定量分析所依據(jù)的基本關(guān)系式是I=acb，式中b是自吸收系數(shù)，α為比例系數(shù)。為了補償因?qū)嶒灄l件波動而引起的譜線強度變化，通常用分析線和內(nèi)標(biāo)線強度比對元素含量的關(guān)系來進(jìn)行光譜定量分析，稱為內(nèi)標(biāo)法。常用的定量分析方法是標(biāo)準(zhǔn)曲線法和標(biāo)準(zhǔn)加入法。
The spectral line intensity of the atomic emission spectrum is proportional to the concentration of I in the sample. The concentration of C is proportional to the concentration of the component. Based on the above analysis, the spectral quantitative analysis. Spectral quantitative analysis is based on the basic relationship is I=acb, B is the self absorption coefficient, alpha as the ratio of. In order to compensate for the experimental conditions of fluctuations caused by the spectral intensity variation, usually with analysis of the relationship between the line and the line intensity ratio of elements for quantitative analysis, known as internal standard method. Standard curve method and standard addition method are commonly used in the quantitative analysis.
原子發(fā)射光譜分析的優(yōu)點是：①靈敏度高。許多元素絕對靈敏度為10-11～10-13克。②選擇性好。許多化學(xué)性質(zhì)相近而用化學(xué)方法難以分別測定的元素如鈮和鉭、鋯和鉿、稀土元素，其光譜性質(zhì)有較大差異，用原子發(fā)射光譜法則容易進(jìn)行各元素的單獨測定。③分析速度快。可進(jìn)行多元素同時測定。④試樣消耗少(毫克級)。適用于微量樣品和痕量無機(jī)物組分分析，廣泛用于金屬、礦石、合金、和各種材料的分析檢驗。
The advantages of atomic emission spectrum analysis are as follows: 1. The absolute sensitivity of many elements is 10-11 ~ 10-13 G. Good selectivity. Many similar chemical properties were measured by chemical method to elements such as tantalum, niobium and zirconium and hafnium, rare earth elements, its spectral properties are quite different, easy to separate determination of elements by atomic emission spectrum law. Analysis speed. Simultaneous determination of multiple elements. The little sample consumption (mg). Suitable for the analysis of trace samples and trace inorganic compounds, which are widely used in the analysis of metals, ores, alloys, and various materials.
