Spectral Interference Correction Research Articles

A Minicomputer-Based Emission Spectrographic Analysis System Dependent on Scanning Microphotometry

A minicomputer-based, semiquantitative, emission spectrographic system was designed to perform survey analyses (64 elements per sample), on a wide variety of geologic materials rapidly (9 s per determination). The system can analyze as many as 40 000 samples per year, while maintaining long-term consistency of results, and can provide archival storage capability (photoplate, microfiche, data bank). The minicomputer's partitioned memory allows simultaneous execution of programs to acquire 92 000 sequential, digitized, transmittance-readings per spectrum from a precision scanning microphotometer in 70 s, and to reduce these data to the peak and background transmittances, the location, and a profile code of as many as 500 analytical lines. The plate emulsion is calibrated in 10 equal segments between 2300 and 4700 Å. Intensities and preliminary concentrations based on prestored analytical curve coefficients are calculated for each line. Corrections for spectral interferences are made, and final results are selected according to a predetermined priority scheme. A report form for every 10 samples is printed within 5 min after a plate is recorded. All the preliminary data are stored on magnetic tape for production of microfiche within 24 h. Spectra on a second plate can be scanned while analysis of the first plate is being performed.

Correction of spectral overlap interference by Zeeman atomic absorption spectrometry

Interference caused by direct spectral overlap can be corrected by Zeeman Atomic Absorption Spectroscopy. Typical cases of interference of this kind appearing in the analysis of Sb were examined. Sb lines at 217.023 nm and 231.147 nm overlap the Pb absorption line at 216.999 nm and the Ni absorption line at 231.096 nm, respectively. In both cases, spectral interference can be eliminated by utilizing the Polarized Zeeman AA Technique. 8 figures, 2 tables.

Cobalt Content of Certain Standard Steel Samples for Spectroscopy

Direct-reading optical emission spectrometers and standardized reference samples are essential to modern steel-making technology. It is most desirable that these samples be as completely analyzed and standardized as possible. A complete standardization of reference samples assists in achieving economy of usage in multielement techniques and assists in the identification of and correction for spectral and other interferences. Further, iron is frequently used as an internal standard in the optical emission spectrometric analysis of ferrous alloys, and the percentage of iron contained the alloy may be used in computation. This iron percentage is commonly calculated by difference and consequently a very complete analysis of the alloy is desirable.

Corrections for spectral interferences in optical emission spectrometry with special reference to the RF inductively coupled plasma

Corrections for spectral interferences in optical emission spectrometry with special reference to the RF inductively coupled plasma

Correction for Spectral Interference with Determination of Lead in Blood by Non-Flame Atomic Absorption Spectrometry

A non-flame atomizer incorporating a graphite tube and cup is used to determine lead in whole blood and packed erythrocytes. In a direct method, a 2-mu-l sample is treated in situ in the cup with 1 mu-l of concentrated nitric acid. The oxidized sample can then be dried, ashed, and atomized without leaving a residue. The nitric acid treatment obviates correction for nonselective absorption, something previously necessary in the determination of lead in blood by non-flame techniques. The resulting chemical conversion of the matrix compounds frees the lead atomic absorption peak from the spectral interference. Alternatively, a 50-mu-l sample of blood or erythrocytes is treated with 50 mu-l of concentrated nitric acid and a 1.5-mu-l aliquot is analyzed with use of the graphite tube.

Improvements in repetitive scanning techniques for reducing spectral interferences in flame emission spectrometry

This paper describes several improvements in the use of the repetitive optical scanning (wavelength modulation) technique applied to the correction for spectral interferences due to line, band, and continuum radiation in flame emission spectrometry (FES). A simple and easily constructed mechanical device for performing the repetitive scan is described, and the procedures for optimizing experimental conditions are discussed. A new technique for the correction for spectral line interferences is introduced. Repetitive scanning FES is used for the analysis of several trace elements in NBS SRM-1633 (fly ash), and the precision and accuracy of results are compared to analysis by normal flame emission techniques.