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Different analytical techniques for the detection of mycotoxins have been developed in order to control the levels of mycotoxins in food and feed. Conventional analytical methods for mycotoxin determination are involving techniques such as thinlayer chromatography (TLC), high-performance liquid chromatography (HPLC) and gas chromatography (GC). Also, rapid methods for mycotoxin analysis have become increasingly important. Enzyme-linked immuno-sorbent assay (ELISA) is one of the most common rapid methods for determination of these natural contaminants. The aim of this study was to provide a comparison between two different methods of analysis (HPLC and ELISA) for the detection of different mycotoxins using data that originate from commercial proficiency tests. Based on the statistical evaluation of the results for both methods, in three proficiency tests for various mycotoxins (aflatoxins, ochratoxin and zearalenone), it could be concluded that both techniques can equally be used, although ELISA is considered to be the screening one., У циљу контроле присуства микотоксина и нивоа контаминације хране и хране за животиње развијене су различите аналитичке технике за детекцију ових природних контаминената. Конвенционалне аналитичке методе за утврђивање микотоксина су танкослојна хроматографија (ТЛЦ), течна хроматографија високих перформанси (ХПЛЦ) и гасна хроматографија (ГЦ). Такође, брзе методе за микотоксиколошке анализе постају све важније, међу којима је ЕЛИСА (Enzyme linked immuno-sorbent assay) једна од најприменљивијих. Циљ овог рада био је да се две различите и најчешће коришћене лабораторијске методе за утврђивање различитих микотоксина (ХПЛЦ и ЕЛИСА) упореде анализом података који потичу из комерцијалних тестова оспособљености (proficiency тестова). На основу детаљне статистичке процене резултата добијених применом ових метода за квантификацију афлатоксина, охратоксина и зеараленона, у три комерцијална proficiency теста, може се закључити да обе технике могу равноправно да се користе с великом поузданошћу, иако се често наводи да је ЕЛИСА погодна само за почетну тријажу узорака.

The lattice constants of a synthetic BaSO4 and fourteen natural barite samples from the Kresevo area (Central Bosnia) were determined by X-ray powder diffraction. The natural samples contained from 0.3-17.6 mole % SrSO4, and negligible concentrations of Ca and Pb (<0.03 and 0.02 wt. %, respectively), thus representing almost pure (Ba,Sr)SO4 solid solutions. The diffraction lines of most natural samples were broadened in relation to those of synthetic BaSO4. This results from obvious compositional heterogeneity, e.g. the heterogeneous distribution of strontium, as is clearly observed from Sr variation patterns across a surface of the barite obtained by proton microprobe analysis. Nevertheless, the present values of unit-cell parameters are in agreement with those of synthetic (Ba,Sr)SO4 solid solutions documented in the literature. It has been proven that the interplanar spacing d004 may be used for determination of the Sr content of natural barites; the absolute error varies from ±0.3 mole % SrSO4 (for homogeneous samples having the diffraction line 004 clearly resolved in spectral doublet components) up to ±0.5 mole % SrSO4 (for the samples with compositional heterogeneity having a broadened and relative poorly defined diffraction line 004).

The lattice constants of a synthetic BaSO4 and fourteen natural barite samples from the Kresevo area (Central Bosnia) were determined by X-ray powder diffraction. The natural samples contained from 0.3-17.6 mole % SrSO4, and negligible concentrations of Ca and Pb (<0.03 and 0.02 wt. %, respectively), thus representing almost pure (Ba,Sr)SO4 solid solutions. The diffraction lines of most natural samples were broadened in relation to those of synthetic BaSO4. This results from obvious compositional heterogeneity, e.g. the heterogeneous distribution of strontium, as is clearly observed from Sr variation patterns across a surface of the barite obtained by proton microprobe analysis. Nevertheless, the present values of unit-cell parameters are in agreement with those of synthetic (Ba,Sr)SO4 solid solutions documented in the literature. It has been proven that the interplanar spacing d004 may be used for determination of the Sr content of natural barites; the absolute error varies from ±0.3 mole % SrSO4 (for homogeneous samples having the diffraction line 004 clearly resolved in spectral doublet components) up to ±0.5 mole % SrSO4 (for the samples with compositional heterogeneity having a broadened and relative poorly defined diffraction line 004).

The metamorphic complex of the Busovaca area is mostly composed of Upper Silurian-Lower Devonian metapelites, metapsammites and metarhyolites formed under low grade metamorphism at 350° to 450°C and 3 to 5 kbars. The ore minerals of the Busovaca deposit are: magnetite (with relics of zincian chrome-spinel), rimmed by ferrichromite, and pyrite, chalcopyrite, enargite, bornite and siegenite. The gangue minerals are: siderite, quartz, albite, hyalophane, muscovite, chromian-chlorite and manganoan ankerite. Proton microprobe analyses (PIXE) were made of samples A (core Ac of the slightly altered chrome-spinel), B (strongly altered chrome-spinel with Bc-core, Bfc-ferrichromite zones, Br-magnetite rim) and C (cryptically zoned magnetite with Cc-core and Cr-magnetite rim). The results are recalculated in formulae, and presented on separate diagrams. The optical investigations, microprobe analyses, beam-scan photographs, diffusion rates of Mg, Al, Zn, Cr, and Mn, and diagrams, allow the following conclusions to be made: (1) magmatic origin of the primary chrome-spinel, (2) the emplacement of the Zn was prior to the alteration under very low f02, most probably synchronous with the sulphide mineralization; (3) the alteration process took place in two phases: (a) the early stage volume-for-volume replacement and formation of the ferrichromite and magnetite zones, (b) the late stage characterized by decolourization and/or resorption, and/or dissolution of the core (patches, specks, “atoll structure”); (4) released Al, Cr, Mn, and Zn have been taken up by silicate, carbonate and oxide minerals forming chromian-chlorite, manganoan ankerite or contaminated siderite and pyrite; (5) the diffusion rates among Al, Zn, Cr, and Mn during different stages of the alteration have the following sequence: Al - Zn - Cr - Mn; (6) the optically unzoned magnetite crystals or aggregates originated in chrome-spinel; (7) the mineral assemblage of the Busovaca deposit co-exists with the surrounding

The metamorphic complex of the Busovaca area is mostly composed of Upper Silurian-Lower Devonian metapelites, metapsammites and metarhyolites formed under low grade metamorphism at 350° to 450°C and 3 to 5 kbars. The ore minerals of the Busovaca deposit are: magnetite (with relics of zincian chrome-spinel), rimmed by ferrichromite, and pyrite, chalcopyrite, enargite, bornite and siegenite. The gangue minerals are: siderite, quartz, albite, hyalophane, muscovite, chromian-chlorite and manganoan ankerite. Proton microprobe analyses (PIXE) were made of samples A (core Ac of the slightly altered chrome-spinel), B (strongly altered chrome-spinel with Bc-core, Bfc-ferrichromite zones, Br-magnetite rim) and C (cryptically zoned magnetite with Cc-core and Cr-magnetite rim). The results are recalculated in formulae, and presented on separate diagrams. The optical investigations, microprobe analyses, beam-scan photographs, diffusion rates of Mg, Al, Zn, Cr, and Mn, and diagrams, allow the following conclusions to be made: (1) magmatic origin of the primary chrome-spinel, (2) the emplacement of the Zn was prior to the alteration under very low f02, most probably synchronous with the sulphide mineralization; (3) the alteration process took place in two phases: (a) the early stage volume-for-volume replacement and formation of the ferrichromite and magnetite zones, (b) the late stage characterized by decolourization and/or resorption, and/or dissolution of the core (patches, specks, “atoll structure”); (4) released Al, Cr, Mn, and Zn have been taken up by silicate, carbonate and oxide minerals forming chromian-chlorite, manganoan ankerite or contaminated siderite and pyrite; (5) the diffusion rates among Al, Zn, Cr, and Mn during different stages of the alteration have the following sequence: Al - Zn - Cr - Mn; (6) the optically unzoned magnetite crystals or aggregates originated in chrome-spinel; (7) the mineral assemblage of the Busovaca deposit co-exists with the surrounding