Interferences Of Rare Earth Elements Research Articles

Spectral interferences in the determination of traces of scandium, yttrium and rare earth elements in “pure” rare earth matrices by inductively coupled plasma atomic emission spectrometry: Part VII — Terbium, Dysprosium, Holmium and Thulium

This article is the seventh part of a series of papers discussing the spectral interferences of rare earth elements (REEs) in ICP-AES. Radial viewing 27.12 MHz inductively coupled plasma atomic emission spectrometry (ICP-AES) was used in the determination of scandium, yttrium and rare earth elements in Tb 2O 3, Dy 2O 3, Ho 2O 3 and Tm 2O 3 as “pure” rare earth matrices. The quantification of the interferences in terms of Q-values for line interference Q I( a) and wing background interference Q W(Δ λ a) were used in accordance with Boumans and Vrakking [Spectrochim. Acta Part B 43 (1988) 69]. The “best” analysis lines from point of view of spectral interferences were selected. The true detection limits by using the “best” analysis lines were calculated.

Spectral interferences in the determination of traces of scandium, yttrium and rare earth elements in ‘pure’ rare earth matrices by inductively coupled plasma atomic emission spectrometry:: Part VI—Ytterbium

The present article is the sixth part in a series of papers discussing the spectral interferences of rare earth elements (REEs) in inductively coupled plasma atomic emission spectrometry (ICP-AES). The spectral interferences in the presence of ytterbium as interferent for 200-pm-wide windows centered (±100 pm) around the prominent lines of scandium, yttrium and REEs were investigated. The quantification of the interferences in terms of Q-value for line interference Q I(λ a ) and Q-values for wing background interference Q W (Δλ a ) was used in accordance with Boumans and Vrakking [Spectrochim. Acta Part B 42 (1987) 819; Spectrochim. Acta Part B 43 (1988) 69]. The excitation temperature, T exc=7200 K was chosen as the optimal in the determination of traces of REEs in Yb 2O 3.

Spectral interferences in the determination of traces of scandium, yttrium and rare earth elements in ‘pure’ rare earth matrices by inductively coupled plasma atomic emission spectrometry. Part V — gadolinium and erbium

The present article is the fifth part of a series of papers discussing the spectral interferences of rare earth elements (REEs) in inductively coupled plasma atomic emission spectrometry (ICP-AES) The spectral interferences in the presence of gadolinium or erbium as interferents for 200-pm wide windows centered (±100 pm) around the prominent lines of scandium, yttrium and REEs were investigated. The quantification of the interferences in terms of Q-value for line interference Q I (λ a ) and Q values for wing background interference Q W (Δλ a ) was used in accordance with Boumans and Vrakking [Spectrochim. Acta Part B 42 (1987) 819; 43 (1188) 69]. The excitation temperature, T exc=6200 K was chosen as the optimal in the determination of traces of RREs in Gd 2O 3 ad Er 2O 3, respectively.

Spectral interferences in the determination of traces of scandium, yttrium and rare earth elements in “pure” rare earth matrices by inductively coupled plasma atomic emission spectrometry. Part IV. Lutetium and yttrium

This article is an electronic publication in Spectrochimica Acta Electronica (SAE), a section of Spectrochimica Acta Part B (SAB). The hardcopy text is accompanied by an electronic archive, stored on the SAE homepage at http://www.elsevier.nl/locate/sabe. The archive contains data files and text files. The present article is the fourth part of a series of papers discussing the spectral interferences of rare earth elements (REEs) in inductively coupled plasma atomic emission spectrometry (ICP-AES). The spectral interferences for 200-pm wide windows centred (±100 pm) around the prominent lines of the analytes, due to matrix lines and oxide radicals (LuO or YO) that emit band spectra depending on the excitation temperature ( T exc.) in ICP were investigated. The main result is that for T exc.=7200 K, LuO and YO band components can be eliminated so that prominent analysis lines of La, Ce, Pr, Nd, Eu and Sm were observed on a smooth background. T exc..=7200 K was chosen as the optimal excitation temperature in the determination of traces of REEs in Lu 2O 3 and Y 2O 3, respectively. The quantification of the interferences in terms of Q-value was used in accordance with Boumans and Vrakking [Spectrochimica Acta Part B 42 (1987) 819; 43 (1188) 69]. The “best” analysis lines are free of line interferences and negligibly influenced by wing interferences and Lu 2O 3 and Y 2O 3 as matrices do not raise the real detection limits.

Spectral interferences in the determination of traces of scandium, yttrium and rare earth elements in “pure” rare earth matrices by inductively coupled plasma atomic emission spectrometry Part III. Europium

This paper is the third part of a series of papers dealing with spectral interferences of rare earth elements (REEs) in inductively coupled plasma atomic emission spectrometry (ICP-AES). The present article shows: (a) the spectral data of europium interferent for 200 pm wide windows centred (±100 pm) about prominent lines of scandium, yttrium and REEs; (b) the database of Q values for line interference ( Q l ) and Q values for (wing) background interference ( Q w); (c) the detection limits measured by using the “true detection limit” criterion as proposed by P.W.J.M. Boumans and J.J.A.M. Vrakking (Spectrochim. Acta Part B, 42 (1987) 819; 43 (1988) 69). Different possibilities for improvement of the true detection limits are discussed: the use of equipment of high resolving power, the application of multicomponent analysis (MCA) techniques and preliminary separation of the matrix component combined with preconcentration of trace REEs. This article is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta Part B (SAB). The hard copy text is accompanied by a disk with data and text files. The data files comprise in particular the tabular material of this article in electronic form.

Spectral interferences in the determination of traces of scandium, yttrium and rare earth elements in “pure” rare earth matrices by inductively coupled plasma atomic emission spectrometry—II: Praseodymium and samarium

This paper is the second part of a series of papers dealing with mutual spectral interferences of rare earth elements (REEs) in inductively coupled plasma atomic emission spectrometry (ICP-AES). The present article covers: (a) the spectral data of praseodymium and samarium interferents for 200 pm wide windows centred (± 100 pm) about prominent lines of scandium, yttrium and REEs; (b) the data base of Q values for line interference ( Q 1) and Q values for (wing) background interference ( Q w); and (c) the detection limits measured by using the “true detection limit” criterion as proposed by Boumans and vrakking [ Spectrochim. Acta 42B, 819 (1987); 43B, 69 (1988)]. The lines with the lowest values of true detection limits for praseodymium and samarium matrices were chosen for analysis. This article is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta Part B (SAB). The hardcopy text is accompanied by a disk with data and text files. The data files comprise in particular the tabular material of this article in electronic form.

Simulation of atomic spectra—II. Mutual spectral interferences of rare earth elements in the inductively coupled plasma

This article is an electronic publication in Spectrochimica Acta Electronica (SAE), the electronic section of Spectrochimica Acta B (SAB). The hardcopy text, comprising the main article and an appendix, is accompanied by a diskette with a program, data files, and a manual. The text details the purpose of the work, with emphasis on the spectroscopic aspects, and the appendix provides the essential information for accessing the diskette and using program and data. Additional tutorial guidance is provided by the manual. The program primarily concerns the simulation of the spectra of rare earth elements (REE) as interferents in 80-pm wide spectral windows centred about the wavelengths of 26 prominent lines of Ce, La, Nd, Pr, and Sm. The program essentially covers the model described in Spectrochim. Acta 43B, 1365 (1988) and the database is identical to the experimental database published in Spectrochim. Acta 44B, 31 (1989). Accordingly, the data are for an inductively coupled plasma (ICP). The program enables the user to simulate spectra with the spectral bandwidth as an optional variable. The user may then generate spectra of both single REEs, without or with analyte, and mixtures of REEs of any composition, also without or with analyte, whereby for spectra with analyte the display includes the blank spectrum. Displays are accompanied by legends providing a set of essential numerical data. In addition, particular program options allow the generation of numerical data only, one of them being the calculation of true detection limits. This option permits it to perform, within the limited scope of the database, line selection for complex REE samples in a rational way. The program operates, in principle, with the default values of the ICP Doppler temperature (6800 K) and “average” ICP a-parameter of the Voigt profile (0.5), but these values may be optionally modified. Similarly, the user may add new data files to the base and thus also apply the program for other purposes and outside the REE environment, such as model studies in general, and for learning or teaching, as explained in the manual on the diskette. The tutorial part of this manual provides the user not only with elementary instructions for using the program as a practical tool, but also incorporates a variety of instructive examples, including a brief “course” on spectral line profiles and spectral interferences.

Mutual spectral interferences of rare earth elements in inductively coupled plasma atomic emission spectrometry—III: Pseudo physically resolved spectral data: complete results and evaluation

This paper directly links up with Part II [ Spectrochim. Acta 43B, 1365 (1988)], which treats the complete theory and contains representative examples. The present work produces the “complete” results and their evaluation. The results essentially consist of pseudo physically resolved spectral data for 14 rare earth elements (REE) in 80-pm spectral windows of 26 prominent analysis lines of Ce, La, Nd, Pr, and Sm, viz., peak wavelengths, hyperfine structure widths, and Q-values of lines and background normalized to a spectral bandwidth of 1 pm. These data, along with an application program, permit the simulation of spectral scans for any specified bandwidth. The paper provides an extensive evaluation and assessment of the vast amount of new spectroscopic data. Internal consistency is checked by comparing simulated and experimental scans for two bandwidths of the echelle spectrometer with which the primary data were measured in a 50-MHz ICP. In this assessment, both the overall likelihood and—quantitatively—the equality of the experimental and calculated Q-values at the wavelengths λ a of the analysis lines ( Q Ij a) are used as criteria. External consistency is tested by comparing the present results with those of recent measurements in a 27-MHz ICP using a common grating spectrometer. Peak wavelengths, peak Q-values and Q Ij a-values (and the corresponding Q Wj a) are used in this comparison. Finally, the paper also compares the present results with the data listed in the MIT and NBS Tables. The number of REE lines identified in the 26 spectral windows of 80 pm width was 1075, which compares with 358 in the compilation for the other ICP, 260 in the MIT Tables, and 134 in the NBS Tables, while the ranges on the Q I-scale were 10 6, 1000, 500, and 170, respectively. The work has shown (a) the overall usefulness of the “ Q-concept” as a quantity for expressing “intensities” of interfering lines, (b) the validity of tranferring Q-values from the one ICP to the other, and (c) the appropriateness of the model and the associated data for simulating spectral scans for spectrometers of “whatever” type and bandwidth. On the whole, the work has demonstrated that the approach is entirely viable. It has provided an extensive data set and a reliable model for manipulating the data in such a way that faithful simulations can be obtained for a multiplicity of “spectroscopic situations”. This, in turn, permits case studies without the need of time-consuming experimental work.

Mutual spectral interferences of rare earth elements in inductively coupled plasma atomic emission spectrometry—II. Approach to the compilation and use of pseudo physically resolved spectral data

This paper is the second part of a series of three papers dealing with mutual spectral interferences of rare earth elements (REE) in inductively coupled plasma atomic emission spectrometry (ICP-AES). The present paper describes an approach to compiling spectral data and modelling spectra in such a way that spectral scans of interferents in 80-pm wide windows centred about prominent analysis lines can be simulated over a broad range of spectral bandwidths (BW). Experimental data are collected at spectral BWs between 4 and 8 pm and reduced to “pseudo physically resolved data”, whereby hyperfine structure (HFS) composites are modelled as trapezia with “Voigt shoulders”, characterized by a “HFS width”. In convolutions with the spectral instrumental function of the spectrometer, the pseudo physically resolved data can be formally treated as truly physically resolved data, provided that the spectral BW is not substantially smaller than that used in the present measurements. The approach characterizes the peak intensities of interfering lines in terms of sensitivity ratios with respect to the analysis lines (in Part I termed “ Q-values”). The dependence of these Q-values on both the BW and the physical widths of the interfering and analysis lines is taken into account. It is shown that both the scans from which the basic data were derived and scans at essentially poorer resolution (about 17 pm BW) can be well simulated. In particular, it is demonstrated that Q-values at the wavelengths of the analysis lines, crucial for the calculation of true detection limits, can be predicted with a most reasonable accuracy ( i.e., to within a factor of 1.0 to 1.5 with respect to measured values). The paper discusses the theory and its application using typical situations, including pitfalls, for illustration. It is finally shown that the measuring technique in its own right permits the identification of typically 34 lines of 13 REEs in an 80-pm spectral window, the sensitivity of the faintest line being 1 20000 ofthat of the analysis line. The numbers 34 and 1 20000 compare with 4 and 1 80 for the NBS Tables, 8 and 1 100 for the MIT Tables, and 11 and 1 1000 for a recent in-house compilation for the ICP.

Mutual spectral interferences of rare earth elements in inductively coupled plasma atomic emission spectrometry: I. Rational line selection and correction procedure

This paper is the first part of a series of three papers dealing with mutual spectral interferences of rare earth elements (REE). The present paper reports the measurement of the partial sensitivities of all REEs at the peak wavelengths of 30 prominent lines of Ce, La, Nd, Pr, Sm, and Yb, the most abundant REEs in geological samples. These sensitivities are split into line and wing contributions and are ratioed with respect to the analyte sensitivities. The “Q-values” thus obtained, along with the numerical values of the background equivalent concentrations for the pure solvent and the relative standard deviation of the background, permit a rational selection of analysis lines for REE mixtures of whatever composition using as a criterion the “true detection limit” as proposed by Boumans and Vrakking [ Spectrochim. Acta 42B, 819 (1987)]. The effectiveness of this approach is illustrated with examples. The data listed are likely to be also appropriate for other spectrometers having a spectral bandwidth of approximately the same magnitude as that used in the experiments, i.e. 17 pm. Therefore the paper includes brief instructions for applying the data. The article finally demonstrates the use of the same data for multielement interference corrections.