Determination of arsenic by hollow-cathode emission spectrometry

1984 ◽  
Vol 156 ◽  
pp. 121-127 ◽  
Author(s):  
A. Alimonti ◽  
S. Caroli ◽  
F. Petrucci ◽  
C. Alvarez Herrero
1981 ◽  
Vol 35 (3) ◽  
pp. 302-307 ◽  
Author(s):  
Bo Thelin

A high temperature hollow cathode lamp from Applied Research Laboratories, Luton, was used for multielement determination of trace elements in steels, nickel-base alloys and ferroalloys. A 10-mg sample (chips) was placed inside a hollow graphite electrode in the lamp, which was filled with helium. It was possible to raise the power through the lamp linearly and automatically, so that the combined thermal and sputtering effect in the lamp atomized the different elements one after another according to their boiling points. This selective volatilization improved the precision and the limits of detection for the elements determined. Analysis results for Pb, Bi, Zn, Ag, Sb, and Ca in the concentration range 0.05 to 100 μg g−1 are discussed. Because of the effective atomization in the lamp, no matrix effects were observed for these elements. One of the main purposes of this investigation was to study the time dependence of the intensity for the different elements during the volatilization phase. This procedure gave very clean spectra. In this investigation a new computerized image dissector echelle spectrometer, was used as the registration system.


2009 ◽  
Vol 63 (8) ◽  
pp. 971-973 ◽  
Author(s):  
Ejaz UR Rehman ◽  
Shakeel UR Rehman ◽  
Shafaat Ahmed

A simple method has been developed for the determination of 6Li atom % using combined atomic emission–absorption spectrometry employing a commonly available natural lithium hollow cathode lamp. Unlike in previous practice, there is no need for specially fabricated and high cost 6Li and 7Li monoisotopic lamps in this method. The method requires adjustment of total lithium contents of the sample, i.e., 6Li + 7Li, to 2 μg-mL−1 based upon atomic emission spectroscopy (AES) ( Caes) against a 2 μg-mL−1 natural lithium standard. The concentration of the sample was then analyzed by atomic absorption spectroscopy (AAS) measurements ( Caas). The difference between the concentration measured by AES and AAS, i.e., Caes — Caas, was calculated. The magnitude of the difference was found to be a function of 6Li fraction in the sample. A calibration curve was constructed by plotting 6Li atom % versus [( Caes — Caas)/ Caes] X 100. 6Li atom % of an unknown sample can be evaluated by putting its [( Caes — Caas)/ Caes] X 100 value in the calibration curve. The method is fast, convenient, and precise.


2018 ◽  
Vol 84 (12) ◽  
pp. 5-19
Author(s):  
D. N. Bock ◽  
V. A. Labusov

A review of publications regarding detection of non-metallic inclusions in metal alloys using optical emission spectrometry with single-spark spectrum registration is presented. The main advantage of the method - an extremely short time of measurement (~1 min) – makes it useful for the purposes of direct production control. A spark-induced impact on a non-metallic inclusion results in a sharp increase (flashes) in the intensities of spectral lines of the elements that comprise the inclusion because their content in the metal matrix is usually rather small. The intensity distribution of the spectral line of the element obtained from several thousand of single-spark spectra consists of two parts: i) the Gaussian function corresponding to the content of the element in a dissolved form, and ii) an asymmetric additive in the region of high intensity values ??attributed to inclusions. Their quantitative determination is based on the assumption that the intensity of the spectral line in the single-spark spectrum is proportional to the content of the element in the matter ablated by the spark. Thus, according to the calibration dependence constructed using samples with a certified total element content, it is possible not only to determine the proportions of the dissolved and undissolved element, but also the dimensions of the individual inclusions. However, determination of the sizes is limited to a range of 1 – 20 µm. Moreover, only Al-containing inclusions can be determined quantitatively nowadays. Difficulties occur both with elements hardly dissolved in steels (O, Ca, Mg, S), and with the elements which exhibit rather high content in the dissolved form (Si, Mn). It is also still impossible to determine carbides and nitrides in steels using C and N lines. The use of time-resolved spectrometry can reduce the detection limits for inclusions containing Si and, possibly, Mn. The use of the internal standard in determination of the inclusions can also lower the detection limits, but may distort the results. Substitution of photomultipliers by solid-state linear radiation detectors provided development of more reliable internal standard, based on the background value in the vicinity of the spectral line. Verification of the results is difficult in the lack of standard samples of composition of the inclusions. Future studies can expand the range of inclusions to be determined by this method.


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