The role of chemical elements to ensure and promote our health is undisputed. Some of them are essential for plants, animals and human, others can cause diseases. The major source of mineral constituents is food, drinking water has a minor contribution to it, so the knowledge of elemental intake through food is crucial and needs continuous moni...toring and by this way it promotes the food quality assurance and dietetics.
With the evolution of spectroscopic methods increasingly lower concentrations could be determined, so the elemental composition of a sample could be more precisely and fully described. Due to the results the gathered knowledge up to the present is supported and new observations can be done helping us to understand such complex systems as biological organisms are.
The quality of a food is determined by the full process of its production, consequently it starts with agricultural production so elemental-analysis usually cover the whole soil – plant – (animal) – food chain, by this way the „Fork-to-Farm” precept is true in elemental analysis field also.
The history of elemental analysis in the University of Debrecen, Centre for Agricultural and Applied Economic Sciences, Faculty of Agricultural and Food Sciences and Environmental Management, Institute of Food Processing, Quality Assurance and Microbiology goes back to 1980s when the so called Regional Measurement Central gave the background for research. The continuous deployment resulted in an obtain of an inductively coupled plasma atomic emission spectrometer (ICP-AES) in 1988, which extended the scope of examinations due to its excellent performance characteristics
compared to flame atom absorption (FAAS) and flame emission spectrometers (FES). The instrumental park retain up to date correlate to the developing analytical techniques due to acquiring a newer ICPAES in 1998 and an inductively coupled plasma mass spectrometer in 2004 – which sensitivity is three order of magnitude better compared to ICP-AES. The Institute supports the work with its own ICP-AES and ICP-MS since 2011.
In the field of elemental analysis inductively coupled plasma mass spectrometers (ICP-MS) have the best sensitivity that means the lowest limit of detection, subsequently their applicability for the detection of essential and toxic elements in foods and foodstuffs is prominent. For the most elements could be measured the detection limit is betw...een μg kg-1 (ppb) and ng kg-1 (ppt) e.g. for arsenic and selenium.
Considering an analytical task (sample type, analytes and their concentration, pretreatment procedure etc.) the applicability of an analytical method is determined by its performance characteristics. The purpose of validation is to ensure that the method would be used fulfills the requirements of the given task. In this article we describes one of the performance characteristics, the linearity, and the whole validation procedure aims measurement of arsenic and selenium in foodstuffs by inductively coupled plasma mass spectrometer (Thermo XSeries I.); but because of the limited number of pages the results are demonstrated only for arsenic.
The linearity of calibration was evaluated in three concentration ranges (0.1–1 μg l-1; 1–10 μg l-1; 10–50 μg l-1), with nine line-fit possibilities (without weighting, weighting with absolute or relative deviation; with or without forcing the curve through blank or origin) and different methods (graphical examination, correlation coefficient, analysis of variance).
The best method to ensure the linearity of correspondence between signal and concentration was the ANOVA test. In view of calibrations it was found that the range of 10–50 μg l-1 could be regarded as linear with four line-fit possibilities, and was non-linear between 0.1–1 μg l-1 and 1–10 μg l-1.
In the course of our examination, we assessed biometric data that determine gender, we evaluated sexual activity, measured the nourishment and necropsies of two feral pigeon populations feeding and nesting at animal breeding farms. The changes in the body weight of the different genders were significant on both farms (p<0.05).
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On both farms, the elemental food source of the birds was the fodder and corn kernels given to cattle, and was supplemented by that of the pigeons living at the Debrecen farm with food from surrounding farms and with other seeds (pea, millet, rye).
By the examination of the genitals, the birds collected from the Nyírbátor farm showed sexual activity from the beginning of spring, and in the summertime decreasing activity is characteristic, while the pigeons from the Debrecen farm are only active from the summer months. In the course of the examinations in the Veterinary Institute of Debrecen, the birds proved to be free of parasites and the results of the Newcastle disease analysis were negative as well. The bacteriologic analyses showed a different proportion of E.coli, Pasteurella multicoda, haemolysing Staphylococcus bacteria at the two cattle farms. During the examinations for the statement of Salmonellas, this causative agent was stated only in case of birds that spend nights and nested in the town, which allude to human origin. We demonstrated Eimeria oocysts during the parasitological examination of the fecal samples in 5 cases at the Debrecen, and in 1 case at the Nyírbátor farm.
Toxic elemental contents are one of the food safety risks in wines. Therefore International Organization of Vine and Wine (O.I.V.) defined the limit of some elements in it. Thirty Hungarian blaufränkisch wines were analysed by ICP-MS in order to determine the concentration of toxic elements. All wines are passed by the O.I.V limits to toxic el...ement content (Cu, Zn, Cd, Pb) according to analysis. Copper is the only outlier in some samples, but they also did not overstep the limit. In the case of zinc the maximum is approximately fourth, in case of cadmium and lead the highest concentration is less than tenth and sixth of the O.I.V. limit, respectively.