Zeeman原子吸收光谱分析法中谱线轮廓的研究I.原子发射谱线.原子吸收谱线和Zeeman原子吸收谱线轮廓间重叠关系图的建立

详细报道用理论计算和绘制的37个元素分析线的发射轮廓. 吸收线轮廓和Zeeman分裂后的吸收线轮廓, 并建立了在原子吸收光谱法中三者轮廓间的重叠关系     

Zeeman原子吸收光谱分析法中谱线轮廓的研究 Ⅰ.原子发射谱线、原子吸收谱线和Zeeman原子吸收谱线轮廓间重叠关系图的建立

详细报道用理论计算和绘制的37个元素分析线的发射线轮廓、吸收线轮廓和Zeeman分裂后的吸收线轮廓,并建立了在原子吸收光谱法中三者轮廓间的重叠关系图.     

Zeeman原子吸收光谱分析法中谱线轮廓的研究(Ⅳ)──Te 214.3 nm和Te 225.9 nm谱线

Te214．3nm和Te225．9nm谱线分别是原子吸收光谱分析（AAS）法中Te的灵敏线和非灵敏线．在Zeeman原子吸收光谱分析（ZAAS）法中,尤其当Zeeman调制方式不同时,分析性能的差异非常明显,颇为典型．本文从原子吸收光谱法的基本原理,即原子发射（AE）、原子吸收（AA）和Zeeman原子吸收（ZAA）谱线轮廓间重叠关系留［‘］来研究其分析特性差异的原因以及在实际分析工作中的应用．1理论部分在原子吸收光谱法中吸光度值A和原子吸收系数间的关系式为：普通AAS法：AN一043K“（1）偏振调制方式ZAAS法：AZ（。;一0．43［K：一大：］…     

Zeeman原子吸收光谱分析法中谱线轮廓的研究Ⅱ.ZAAS法中Rz值研究

报道依据原子吸收光谱(AAS)法的基础,即谱线轮廓间重叠关系图,和Rz的定义,对常用的38条谱线的R~z~(~a~c~)和R~z~(~d~c~)进行了理论计算, 并与相应的实验数据作了对比分析研究两者差值在10%的谱线数目,R~z~(~a~c~)为33条,R~z~(~d~c~)为22条.     

Zeeman原子吸收光谱分析法中谱线轮廓的研究Ⅱ.ZAAS法中Rz值研究

报道依据原子吸收光谱(AAS)法的基础,即谱线轮廓间重叠关系图,和R_z的定义,对常用的38条谱线的R_(Z_(ac))和R_(Z_(dc))进行了理论计算,并与相应的实验数据作了对比分析研究.两者差值在10%的谱线数目,R_(Z_(ac))为33条,R_(Z_(dc))为22条.     

Zeeman原子吸收光谱分析法中谱线轮廓的研究Ⅴ.Ag328.1nm的分析性能

从理论和实验两方面研究和讨论了在ＺＡＡＳ法中，不同调制方式及磁感应强度对Ａｇ３２８．１ｎｍ的分析性能的影响，并取得一致的结果     

Zeeman原子吸收光谱分析法中谱线轮廓的研究

人和实验两方面研究和讨论了在ＺＡＳ洁，不同调制方式及磁感应强度对Ａｇ３２８．１ｎｍ的的分析性能的影响，并取得一致的结果。     

塞曼原子吸收光谱法中谱线轮廓研究：Ⅲ.π成分作用

分析了塞曼原子吸收光谱(ZAAS)法中π成分的作用,特别对横向磁场调制ZAAS法中偏光元件与π成分作用间的关系进行了详细讨论。报道了32种元素的34条谱线在无偏光元件条件下的相对灵敏系数(R_x(nP))的理论计算值与实验测定值。     

用次灵敏线原子吸收法测定铅锌矿石中铅锌

微量铅锌的原子吸收分析报道很多.矿石中高含量铅锌的测定,通常采用络合滴定法,但干扰较多、流程较长.高含量铅锌的原子吸收直接测定,则所见报道不多.本文研究了利用次灵敏线测定矿石中高含量铅锌.样品经酸溶并定容到一定体积后,可不经稀释用原子吸收仪直接进行铅、锌测定.方法简便、快速.检测结果与按国家标准分析方法结果比较,其准确度、精密度均符合要求.1试验部分1.1仪器与试剂GGX-1型原子吸收分光光度计铅、锌标准液:2.000mg·ml~(-1),2%硝酸(体积分数,下同).其他试剂均为分析纯1.2仪器工作条件选择次灵敏线铅368.4nm,锌307.6nm,空气-乙炔火焰比例根据仪器情况调整.因铅、锌灵敏度及线性范围受火焰影响,故测量过程中要求火焰状态     

Calculation of some line profiles in ICP-AES assuming a Van der Waals potential

Some line profiles in ICP-AES have been calculated using the assumption of a Van der Waals potential to describe the broadening due to collisions between atoms or ions of analyte elements and neutral atoms of argon (or helium). The FWHM values are in a range between 10 and 100mÅ and are an order of magnitude larger than those obtained with the kinetic theory of gases.Conclusions are given as to the different influences of various types of broadening (pressure, Doppler, Stark and resonance) after the convolution of each profile, on the spectral interferences resulting from overlap of line wings. The influence on the separation between two lines is also discussed.     

Interferometric measurements of atomic line profiles emitted by hollow-cathode lamps and by an acetylene-nitrous oxide flame

Source line profiles for eighteen atomic transitions of nine elements emitted by low-current hollow-cathode lamps and by an acetylene-nitrous oxide flame have been measured with a Fabry-Perot interferometer. Distortions caused by instrument broadening are shown to be negligible. Contribution of self-absorption to the profile widths is estimated. In nearly all cases hyperfine structure has a decisive influence upon the observed profile. For thirteen transitions of known hyperfine structure the experimental curves are compared with computer simulated spectra using Gaussian functions to derive the Doppler temperature of hollowcathode lines and Voigt functions to calculate the collision broadening of flame lines. The results show that the Doppler temperatures of hollow-cathode lines range from 400 to 700°K, that flame lines are significantly shifted to the red and that collision broadening in the flame is fully comparable to Doppler broadening, i.e. the a-parameter varies between 0.5 and 1.5.     

Time- and wavelength-resolved emission line profiles for pulsed Cu and Ag hollow cathode lamps

Time-resolved, line emission wavelength profiles were obtained for a copper and a silver pulsed hollow cathode lamp with the use of a piezoelectrically driven interferometer. A computer was used to control the timing of the sweep of the interferometer, the pulsing of the source, and the acquisition, averaging, sorting and display of data. Minor manipulation of the data stored in core facilitated the presentation of intensity vs wavelength emission profiles in a time-resolved form. Ten sequential line profiles spaced at 21 μsec time intervals were obtained.The copper hollow cathode lamp was driven at 100 Hz with pulse currents of up to 400 mA. Pulses lasted for up to 300 μsec. Line profiles changed dramatically during a pulse and showed extreme self-reversal of the resonance emission lines after 100 μsec. Variations of line profile with dc background current level and spatial position within the discharge were also investigated. Uncorrected line widths of each of the doublets of the Cu(I) 324.7 nm resonance line measured during the first 21 μsec of the discharge, where they were narrowest, ranged from 0.0012 to 0.0022 nm, including an instrumental broadening contribution estimated to be less than 0.0004 nm. The silver lamp showed extreme self-reversal even during the first 21 μsec.     

Interferometric measurements of spectral line widths emitted by an inductively coupled plasma

Line widths of fifteen spectral lines of ten elements introduced into an inductively coupled plasma (ICP) have been measured with a Fabry-Pcrot interferometer. Instrumental broadening is estimated by measuring the line widths emitted by hollow-cathode lamps and assuming their actual profiles as purely Gaussian with Doppler widths at 400 K. For correction of the experimental widths of lines emitted by the ICP, actual profiles of the lines are assumed to be purely Gaussian as a first approximation. The calculated actual widths range from 0.0015 to 0.0051 nm. Values of the a-paramctcr of the Voigt profile are estimated by assuming the Doppler temperature of the plasma to be 5000 K. Most of the lines emitted by the ICP have a-values in a range between 0.2 and 0.7. The fact reported previously that ICP lines suffer from less collisional broadening than lines excited in flames is supported.     

Automated parameter optimization in modeling absorption spectra and resonance Raman excitation profiles

An automated method is described for optimizing the molecular parameters in simultaneous modeling of optical absorption spectra and resonance Raman excitation profiles. The method utilizes a previously developed Fortran routine that calculates absorption spectra and Raman excitation profiles for polyatomic molecules in solution from a model for the potential energy surfaces and spectral broadening mechanisms. It is combined here with an optimization routine from the commercial MATLAB package that iteratively adjusts the parameters of the molecular model to minimize the least-squared error between calculated and experimental spectra. Optimizations that typically require days to weeks of human time when performed interactively can be accomplished automatically in less than an hour of computer time. The method can handle large molecules (we show results for as many as 23 Raman-active modes) and mixtures of spectral broadening mechanisms (lifetime, Brownian oscillator, and inhomogeneous), and is robust toward noise or missing data points.     

Axial profiles of excitation and gas temperatures in an inductively coupled plasma

A vertically movable horizontal slit driven by a computer-controlled stepping motor was placed close to the front of the entrance slit of a monochromator. The axial channel of the plasma being imaged onto the entrance slit, the observation height was scanned by slicing the image of the plasma with the horizontal slit. Excitation and gas temperature profiles were calculated under various operating conditions from emission profiles of Fe I and OH lines, respectively. From the axial emission and temperature profiles, two excitational regions governed by different excitation mechanisms were postulated along the axis of the plasma. In the first region from 0 to 8 mm above the load coil, low-energy lines were predominantly excited and their emission profiles were controlled mainly by the dissociation rate of molecules. In the second region from 10 to 20mm above the load coil, high-energy lines were predominant and volatilization interferences were small.     

Excitation profiles of resonance raman spectra in condensed media

A simple model, obtained by reducing a multimode system to a simple coordinate, is proposed to explain the broadening of RRS in liquid or solid media. It is shown that the coherent excitation of the near continuous background of low-frequency modes can cause homogeneous broadening of RRS profiles. The model is applied to the excitation profile of β-carotene.     

Observation of spectral line profiles emitted by an inductively coupled plasma—I.: On the wavelength shift of spectral lines

Profiles of 16 spectral lines stemming from 8 elements (Ar, Na, Cu, Sr, Cd, Ba, Mg and Li) emitted by an inductively coupled plasma (ICP) have been observed and measured with a pressure-scanning Fabry-Perot interferometer. In the process of profile observations, we have found wavelength shifts of spectral lines in an ICP and for the first time studied this phenomenon quantitatively and systematically in a spectrochemical source. The profiles of spectral lines emitted by the ICP have been compared with those emitted by hollow cathode lamps. The magnitude of the wavelength shift to the red or the blue varied more or less with the plasma conditions, observation position and the concentration of a concomitant, cesium. In the present work the observed line profiles were not deconvoluted for the apparatus profiles. Typically the order of magnitude of the wavelength shift measured for spectral lines that show large shifts at an observation height of about 4 mm in an “analytical” ICP is n × 10^?3 nm, where n is about 4 for Ar I 427.2 nm and about 1 for Cu I 521.8 nm and Sr II 430.5 nm. With regard to the wavelength shift, several trends and/or regularities were found. The Stark effect is considered as the main cause of the phenomena.     

Asymmetric Stark broadening of the Fe I 538.34 nm emission line in a laser induced plasma

In this work asymmetries along with shifts in the line profiles of neutral iron emission lines coming from a laser induced plasma have been detected. The plasma was produced in air at atmospheric pressure on a 50% Fe–Ni alloy and the emission was collected at a temporal window of (2.5, 3) μs. To avoid the effect of spatial inhomogeneity on the profiles, a deconvolution procedure was applied to obtain the spatially resolved emissivity. Asymmetric theoretical Stark profiles, which take into account the effect of static ions, were used to be fitted to the experimental data of the emission profile of the line Fe I 538.34 nm. The fitting of the theoretical profile to the experimental data was carried out by means of the least squares method using genetic algorithms to automatically solve the optimization problem. The correlation coefficient was higher for the asymmetric fits than for the symmetric ones. From the fit, the quasistatic ion broadening parameter α, the electron broadening parameter w_e, and the total shift of the maximum of the line d_t, were obtained. The ion parameter α varied in a range (0.2–0.3) for an electron density between (4–15) × 10¹⁶ cm^− 3. The ion influence on the total broadening was of 15–20%. The total shift varied in the range (0.01–0.06) nm and it was mainly given by the ion shift, the electron shift being negligible. For the electron density range in this work, approximated linear behaviors of the total width and shift with electron density have been obtained.