Validation of the method for determination of lead, cadmium, arsene in meat and meat products atomic-absorption spectrometry with electrothermal atom

The toxicity of heavy metals poses risks to the health of both humans and animals based on their ability to accumulate in the body. The toxicity of the metal depends on the absorbed dose, route and duration of exposure. The timely determination of heavy metals in food, in accordance with EU-approved assessment methods, is an urgent task. The aim of the study was to validate the method of determination of lead, cadmium, arsenic in meat and meat products by atomic absorption spectrometry with electrothermal atomization. The Thermo Solaar atomic absorption spectrophotometer (USA) was used to determine arsenic and cadmium, and the Varian 240 G atomic absorption spectrophotometer (Australia) was used to determine lead. Nitric acid (Merk, Germany), certified standard solutions (Merk, Germany) according to the approved methods were used for mineralization of samples and preparation of background, calibration solutions. The validation characteristics of the method for determining lead, cadmium, arsenic by atomic absorption spectrometry with electrothermal atomization, namely: detection limit, quantitative limit, accuracy, correctness, convergence, reproducibility, selectivity, linearity. The accuracy, practicality and versatility of this method have been proven, which is confirmed by LOD and LOQ: for lead 0.31, 10.0 μg / kg, cadmium 0.3 and 5.0 μg / kg, arsenic 0.2 and 10.0 μg / kg. The results obtained and the validation data on accuracy and reproducibility are in line with the requirements of European legislation on the residual content of heavy metals in meat and meat products.

SPECIFIC FEATURES OF DISTRIBUTION OF MINERALS IN ORGANS AND TISSUES OF HERRING SPECIES (CLUPEIDAE) IN CASPIAN SEA

Research objective was to identify the specific features of distribution of microelements (zink, manganese, lead, cadmium) in organs and tissues of black-backed shad Alosa kessleri kessleri (Grimm, 1887) and Dolginsky herring Alosa braschnikowii braschnikowii (Borodin, 1904) caught in the Caspian Sea. Accumulated in the tissues and organs of fish in concentrations exceeding the maximum permissible limits, heavy metals pose a danger to human health. Sampling was carried out by the standard techniques, definition of minerals was made by method of atomic and absorbing spectroscopy using an atomic and absorbing spectrometer with electrothermal atomization of MGA-915 MD. The analysis of the obtained data showed that distribution of minerals in the organs and tissues of the studied herring species had a similar pattern: the highest concentrations of minerals were registered in the gills and liver, the smallest - in muscle tissue. In comparison with black-backed shad the organs and tissues of Dolginsky herring had higher concentrations of chemical elements. Zinc has been found to accumulate mainly in the liver; manganese, lead and cadmium - in the gills. Accumulation of zinc, cadmium and lead in the studied bodies and tissues of fishes exceeded acceptable level.

Deep eutectic solvent decomposition-based microextraction for chromium determination in aqueous environments by atomic absorption spectrometry with electrothermal atomization

A sensitive, rapid, and simple procedure for the determination of traces of chromium species in natural and waste waters after microextraction using quasi-hydrophobic deep eutectic solvent based on tetrabutylammonium bromide...

ASSESSMENT OF POSSIBILITY OF DETERMINATION ELEMENTAL COMPOSITION OF WASTEWATER USING SMALL-SIZE ATOMIC-ABSORPTION SPECTROMETER WITH CONTINUOUS SPECTRUM SOURCE

The article is devoted to the evaluation of analytical capabilities of a small-size atomic absorption spectrometer, which differs from traditional atomic absorption devices in that it allows to register the whole absorption spectrum of the sample in one cycle of electrothermal atomization, thus significantly increasing the efficiency of the analysis. The evaluation of the analytical capabilities of the developed prototype was based on the example of wastewater analysis, because this type of analysis has the least stringent requirements for detection limits and the number of elements to be determined, but is also a very important task. Based on the results obtained, it has been concluded that a small-size atomic absorption spectrometer is capable of detecting 9 out of 32 elements normalized in wastewater with detection limits substantially below the MPC. Determination of another 3 elements will be possible after increasing the resolution of the spectrometer to 22-24 pm.

DETERMINATION OF LOW CONTENTS (LESS THAN 0,0005%) OF ARSENIC IN NICKEL ALLOYS BY ICP-MS AND AAS METHODS WITH ELECTROTHERMAL ATOMIZATION

In this work, the determination of low contents (less than 0,0005 wt. %) of arsenic in complex alloyed samples of nickel alloys was carried out by means of inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry with electrothermal atomization. Also, the ICP-MS method was used to determine the arsenic content in chromium, which is an alloying component of nickel alloys. A technique for dissolving a sample and preparing it for analysis is presented. Spectral interferences are eliminated by applying mathematical correction equations, a reaction-collision cell and using corrective additives. The correctness of the results obtained is confirmed by the analysis of certified reference materials of nickel alloys and chromium.

Determination of Pb (II), Cu (II), Co (II), Mn (II), and Fe (III) by electrothermal atomization atomic absorption spectrometry after preconcentration with nanofibers

The results of sorption preconcentration of some heavy metal (HM) ions with their subsequent determination in natural and drinking water by electrothermal atomization atomic absorption spectrometry (ETAAS) are presented. The sorption and desorption (0.01 – 1 M HNO3) of lead, copper, iron, cobalt and manganese ions from aqueous media on nanofiber samples obtained from polyacrylonitrile (PAN) with subsequent directed modification by 1.25 M NaOH solution upon heating (70°C) (PAN*) are studied and optimized. Nanofibers were obtained by capillary-free electroforming from solutions of PAN in dimethylformamide. This method is advantageous for the simplicity of equipment, high energy efficiency of nanofiber production, versatility and flexibility in controlling process parameters and allows production of nanomaterials with desired properties. The values of the extraction degree (95.8 – 99.5%) and selectivity coefficients for competing pairs of metal ions are calculated: вPb/Cu = 1.2; вPb/Co = 2.8; вPb/Mn = 3.2;вCu/Co = 1.7; вCu/Mn = 3.7; вCo/Mn = 2.5. A comparative analysis of the sorption activity of the obtained nanofibers revealed that the character of lead, copper, cobalt and manganese ion sorption by nanofibers is non-selective at pH 6 – 8 and selective for iron (III) ions at pH  3. A technique of sorption-atomic absorption determination of the aforementioned metal ions in real objects with preliminary nanofiber concentration at the level of tenths and hundredths of MPC is proposed. Non-woven materials based on modified PAN are used as effective extractants of nanogram quantities of HM ions. The detection limits for heavy metal ions are 40 – 80 ng/dm3.