The qualitative analysis of the spectrometer: Due to the atoms structures of each element are different, under the action of light source, can produce own characteristic spectrum. If a sample through by excitation spectrum appears several elements’ spectral line, it’s proved that there are several elements in the samples. This analysis method is called a spectrum qualitative analysis method.
Spectral instrument used for the qualitative analysis method has the following kinds:
1. Comparison spectral analysis method: This method is widely used, it includes standard sample comparison method and iron spectrum comparison method. Standard sample comparison method generally applicable to individual qualitative analysis and limited analysis. Iron spectrum comparison method not only can do single test but also to do the overall analysis.
2. Spectral wavelength measurement method: Spectrum analysis instrument use spectral wavelength measurement method for the qualitative analysis is to measure the wavelength of spectral line first, and then definite to look-up table elements, this method is seldom used in routine analysis, generally in the preparation of spectra or arbitration analysis.
Generally speaking, spectrum analysis instrument qualitative analysis can analyze 70 several elements in the periodic table, but due to the limitation of instrument and light conditions, some elements such as non-metallic and halogen element requires to test in the special conditions.
The sample of spectrum instrument qualitative analysis can be varied, so the spectrum qualitative methods each are not identical, easily conductive metal samples itself can as the electrode use dc or ac arc light source to analysis directly. Sometimes in order not to damage the sample also can use spark source analysis and laser microscopy. For organic matter, first of all for chemical processing, make it into a solution, use solution residue method to test, can burn, ash sample processing into powder evenly in the carbon electrode hole used in dc or ac arc light source analysis determination.
Spectral instrument qualitative analysis’s characteristics is simple, fast speed, need less number of samples and any form of samples can be analyzed. For most of the elements have higher sensitivity. Qualitative analysis can analyze the spectrum of one or more specified element in the sample. According to strong and weak of the sensitive line to determine their roughly content in the sample. Spectrum qualitative analysis can only be given sample element, such as abundant or a small amount or trace, want to get the correct element content must do spectral quantitative analysis.