Ivan Nemet

Tin Content Determination in Canned Fruits and Vegetables by Hydride Generation Inductively Coupled Plasma Optical Emission Spectrometry

Tin content in samples of canned fruits and vegetables was determined by hydride generation inductively coupled plasma atomic emission spectrometry (HG-ICP-OES), and it was compared with results obtained by standard method of flame atomic absorption spectrometry (AAS). Selected tin emission lines intensity was measured in prepared samples after addition of tartaric acid and followed by hydride generation with sodium borohydride solution. The most favorable line at 189.991 nm showed the best detection limit (1.9 μg L−1) and limit of quantification (6.4 μg kg−1). Good linearity and sensitivity were established from time resolved analysis and calibration tests. Analytical accuracy of 98–102% was obtained by recovery study of spiked samples. Method of standard addition was applied for tin determination in samples from fully protected tinplate. Tin presence at low-concentration range was successfully determined. It was shown that tenth times less concentrations of Sn were present in protected cans than in nonprotected or partially protected tinplate.

Elemental Composition and Chemometric Characterization of Pyrethrum Plant Materials and Insecticidal Flower Extracts

The elemental composition of native and cultivated pyrethrum plants (Tanacetum cinerariifolium) and their insecticidal extracts obtained from dried flower heads was determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). The accuracy of the analytical procedure which included pressurized digestion of plant samples in HNO3/H2O2 was tested by certified reference materials. Acceptable recoveries (90–110%) for the majority of elements were obtained measured in a simultaneous multi-element mode. The total pyrethrins content was determined by HPLC and it was 2.09% for cultivated plants and 1.58% for native species. The concentrations of 18 elements and pyrethrin content were subjected to statistical multivariate analysis which showed different patterns among plant parts. The roots were characterized by a combination of loadings of iron, aluminum, nickel, chromium, strontium, and barium, while the stems, leaves, and flowers showed more contributions from sodium, potassium, calcium, magnesium, phosphorus, sulfur, manganese, and copper. A higher loading of pyrethrins was the main characteristic of dried flower extracts. It was also observed that microelements such as copper, aluminum, and iron were more readily transferred into natural insecticide extracts.

Elemental profiling of Noahs Ark shell (Arca noae, Linnaeus, 1758) by plasma optical spectrometry and chemometric tools

Determination of metal content in biominerals provides essential information with respect to relations between biomineralization processes and environmental status. Mussels are species that have a great potential as bio-marker species and therefore, they are in the focus of numerous biomineralization and ecological studies. In this study, elemental profile of mussel shell of Noahs Ark (Arca noe, Linnaeus, 1758), which inhabit eastern Adriatic Sea was obtained by determination of seventeen elements content using inductively coupled plasma optical emission spectrometry (ICP-OES). Shell samples were collected from marine protected area and from marine shipping route in eastern Adriatic Sea. The accuracy of applied analytical procedure based on microwave decomposition of shell samples was tested by use of reference materials of limestone and by matrix-matched standards. By aid of chemometric methods, the elemental profile along with variability of elements content of shell was obtained. The impact of different environment on elements content was established by use of multivariate statistical PCA method. Discernment between two groups of samples was manifested. Among results of main, minor and trace elements content, the last one which denoted to Cd, Co, Cu, Pb, and Mn was expressed as principal distinctive feature of shell samples collected from different sampling sites. Elemental profiling of mussel shell Noahs Ark provides novel insight in species status as well as in environmental status on the observed locations.

Classification analysis of archaeological findings from early-iron production (Turopolje region, NW Croatia) based on multi-analytical profiling

The combination of XRF, SEM-EDS, ICP-AES, ICP-MS, and chemometric methods for the investigation of early-iron production artefacts is presented. Visually similar samples were randomly collected from stored humps of material that was excavated in the Turopolje region, NW Croatia. Elemental analysis of different kinds of slags and pit furnace remains is performed from major (Fe, Si, Al, Ca, K, Mg, P, Mn, and Ti) to trace constituents (Ba, Cu, Cr, Ni, Mo, Pb, V, Zn, Zr, and REEs). Applied statistical analyses (PCA and HCA) for enlarged set of measured data allow the similar features of heterogeneous materials to become clearly discernible. Thus, three types of slags, namely, iron-rich tap slag, bloom slag, and ceramic-rich slag are recognized. Moreover, retrospective examination of morphology data from SEM-EDS observations along with elemental signature and performed statistical treatment enables identification of an exception in a set of slags; it is identified as a non-processed bog iron ore. These results are advantageous for forthcoming multidisciplinary studies of early-iron production in the Pannonic area. The combination of presented methods facilitates recognition of inhomogeneous slag material from archaeometallurgical production sites, especially when numerous similar samples are scattered at an excavation site.