János Borszéki

Sample preparation procedure for the determination of sulphur and trace metals in oil products by the ICP with a minitorch using emulsions

A quick sample preparation method was used for the determination of sulphur and trace metals in oil and oily products by the ICP with a minitorch. Stable aqueous emulsions of oils and oil products were made by using two kinds of emulsifiers (one with low sulphur content, the other sulfonated). Aqueous standard solutions can be used for the preparation of calibration solutions. The contents of S, Al, Cr, Cu, Fe, Mg, Ni and Pb in aqueous emulsions were determined and the results were in good agreement with the composition of oil standard solutions used for control analysis procedure.

Determination of sulfur content of diesel fuels and diesel fuel-like fractions of waste polymer cracking

The element content of low and high sulfur containing diesel fuels was measured by different analytical methods: energy-dispersive X-ray fluorescent (EDXRF) and inductively coupled plasma atomic emission (ICP-OES) spectroscopy methods. Then results were compared. High sulfur containing diesel fuels were from heavy diesel engines and diesel fuel-like liquids obtained by thermal degradation of waste polymers. In case of X-ray analysis also the effect of the used thin foils with different chemical compositions (polypropylene, polycarbonate, polyester) on the accuracy was investigated. According to data considerable differences and deterioration of accuracy was observed in the respect of foils in case of both low and high sulfur containing hydrocarbons. Results indicated appropriate correlation between experimental results measured by both two methods, but differences could be observed in the correlation, which could be explained with different ratio of C/H of samples.

Preconcentration of trace elements on oxine cellulose

SummaryPreconcentration of Trace Elements on Oxine Cellulose 8-Hydroxychinoline, covalently bound to filter cellulose (oxine cellulose), was used for preconcentrating trace metal ions from complex matrices and for matrix separation, respectively. Mn, Fe, Co, Ni, Cu, Zn and Cd traces were preconcentrated on columns filled with oxine cellulose and analysed by AAS and ICP after being eluted with dilute HNO3. At a given pH-value, alkali and alkaline earth metal ions can be quantitatively separated as matrix elements; high concentration factors are obtained and the eluates can be measured without interference. The usefulness of the method is shown by control analyses of EPA- and NBS-SRMs.

Application of pressurized sample preparation methods for the analysis of steels and copper alloys

Pressurized sample preparation devices (High Pressure Asher, Pressurized Microwave Digestion system, compared with a PTFE decomposition vessel) were used to dissolve certified metal alloy samples (steel, copper) for ICP analysis. Based on the results of the analysis it was established that both up-to-date devices can be advantageously applied to quickly and quantitatively dissolve metal alloy samples. To dissolve the samples, two different kinds of acid mixtures (A: nitric and hydrochloric acid; B: nitric and hydrochloric and sulphuric and phosphoric acid) were used. The sample preparation is simpler and less time-consuming than the earlier commonly used methods, sample loss and degree of contamination are also reduced. Steel samples containing tungsten, titanium and niobium (less than 0.5%) can only be analyzed using a mixture of the four acids. By dissolving steel samples in the nitric and hydrochloric acid mixture, the concentration of their most common elements (Cr, Ni, Mn, V, Cu) as well as their S and P content can be determined. Copper alloy samples can be dissolved quickly by the pressurized microwave decomposition device using hydrochloric acid and diluted (1:1) nitric acid.

X-ray fluorescence raw intensities vs. concentration data for multivariate classification of hungarian coal

Abstract A set of coal samples was examined by routine methods of coal analysis (density, calorific value, sulfur content, etc.) and by trace element determinations on the coal ash. Both data sets gave satisfactory clustering of samples from similar geological zones. X-ray fluorescence spectra were evaluated in order to identify the significant data-reduction steps in the sequence raw spectra/net intensities/trace element concentrations that is commonly used in x-ray spectrometry. The deconvolution yielding net intensities from spectra was identified as the most significant step. This was explained by the decorrelation effect of geochemically dissimilar elements.

Application of the Kálmán filter for analysis of complex matrices by ICP-AES☆

Abstract Composition of bauxite samples was determined by ICP-AES. Twelve trace and two matrix elements are investigated: Ba, Cr, Cu, La, Mn, Mg, Sr, Ti, V, W, Y, and Zn and Al and Fe, respectively. Three types of evaluation methods are employed and the results compared to each other as well as to the certificates of standard bauxite samples. Of these three methods one is a single-element evaluation, the second is the Kaiman filter technique, and the third is a multivariate calibration method. In terms of a general assessment of the Kaiman filter, it can be observed that in the example given this method is not much better than the single-element method. The Kaiman filter accomodates all the points in a spectrum including those with high error. In trace element analysis, however, the Kaiman filter performs better and gives more reliable results.