X-ray fluorescence spectrometer SPECTRO iQ II

In August 2008 a simultaneous energy-dispersive X-ray fluorescence spectrometer SPECTRO iQ II was purchased for analytical laboratory. After instrument installation, necessary training of the laboratory staff in the field of both X ray fluorescence spectrometry and instrument operation, verification of spectrometer parameters, testing of measurement conditions and developments of quantitative methods based on large calibration sets we would like to introduce new possibilities of both qualitative analyses and quantitative determinations of many elements contained in your samples. Now we can determine elements, which have not been analyzed yet. The X-ray fluorescence analyzer allows extending the current offer of our laboratory services.

Method principle: A solid, liquid or powder sample is excited in a sample compartment of the analyzer with X-rays emitted from an X-ray tube. The innermost electrons of various atoms are ejected from the inner shells creating vacancies in the process called the photoelectric effect. The vacancies present instable condition for the atomic system. Electrons from outer shells occupy the vacancies; the corresponding energy differences cause an emission of characteristic secondary (fluorescence) X-rays. The radiation frequencies are characteristic for individual elements. The intensity of a particular line corresponds to the content of an element in the sample. All element specific X-ray fluorescence signals from the sample are detected simultaneously in a fixed mounted semiconductor detector and evaluated. Hence, an X-ray fluorescence spectrum is obtained. SPECTRO iQ II instrument uses a polarized primary radiation for increased sensitivity and the noise reduction (especially important for determination of the light elements). The analysis is non-destructive, thus the sample after analysis (eventually after a solvent evaporation) can be used further.

Qualitative analysis: The SPECTRO iQ II spectrometer allows a qualitative detection of elements from Na to U (except Pd) in different types of samples (e.g. liquids, solutions, solid powders) samples (except gases). We have got the cups for analyses of liquid samples (solutions, emulsions and suspensions) and furthermore for powder samples and solid pressed tablets. The limits of detection are different depending on individual elements; commonly they are in range from one to tens ppm.

Quantitative analysis: Currently, we can perform quantitative analyses of the elements, which we have been doing with titration methods, i.e. P, S, Cl, Br and I. A new method for the determination of K is established. Considering the results of many performed tests, both precision and accuracy of results obtained via X-ray fluorescence method is comparable to the current methods' performance characteristics. Nowadays the quantitative analyses are limited to sample solutions in methanol, because the calibration models for methanolic solutions are developed. Thus at least a minimal solubility of analyzed sample in methanol is required to prepare a defined sample solution. For simultaneous analyses of the all elements required we need 2-5 mg of a sample. Of course, this value depends on the content of determined elements in a particular sample.

In fact, we can develop methods for determination of any element (from Na to U except Pd) but we need an appropriate standard (or standards) with a known (certified) content of the element to be determined. In future, it is possible to develop various quantitative methods in several other non-volatile solvents with proper elemental compositions (water, ethanol…) with respect to your requirements.