Determination of total mercury in fish and sea products by direct thermal decomposition atomic absorption spectrometry.

A Zeeman Mercury analyzer Model RA-915(+) (Lumex, St. Petersburg, Russia), based on the direct thermal evaporation of Hg from solid samples was used for developing a method for the determination of Hg in fish and other seafood. The method does not require any chemical pretreatment of samples. This greatly simplifies the analytical procedure and minimises potential sources of contamination. The limit of detection (3s criteria) and limit of quantification (10 s criteria) for the determination of Hg in wet fish samples with a mass of 250 mg was found to be 0.6 ng g(-1) and 2.0 ng g(-1), respectively. Time taken for the analysis of one sample is about 3 min. The accuracy of the method was confirmed by the analysis of certified reference materials of different types and by comparative analysis of fish samples using the accepted method of cold vapour generation. Excellent correspondence to the certified values was obtained. It was found that the mercury concentration in most fish species purchased from the Tshwane fish market were below the 0.5 mg kg(-1) (500 ng g(-1)), wet weight, recommended by the FAO/WHO. It was also found that the direct thermal decomposition method for the determination of mercury is a more environmentally friendly alternative since it does not generate chemical waste.

[Content of trace elements and steroid hormones in blood and tissues of internal organs of rats during an inflammatory process in the bronchi]. / Soderzhanie mikroélementov i steroidnykh gormonov v krovi i tkaniakh vnutrennikh organov krys pri vospalitel'nom protsesse v bronkhakh.

Prolonged interrupted inhalation of nitrogen dioxide in a dose of 36.0 +/- 2.2 mg/m3 was attended by definite morphological signs of inflammation in the lungs of rats (hyperplasia of goblet cells, thickening of the basilar membrane, differentiation of ciliated epithelium, etc.), reduction of the zinc content in all studied tissues and testosterone levels in blood. Intramuscular injection of 1% testosterone propionate normalized the blood level of the hormone and influenced the synthetic processes in the cells of the bronchial epithelium and the rate of its regeneration. To raise the efficacy of the correction of the pathological process in the lungs it is suggested that hormonal therapy should be combined with correction of zinc deficiency in the organism.

[Content of trace elements and steroid hormones in blood and tissues of internal organs in experimental pulmonary fibrosis induced by intratracheal administration of bleomycetin]. / Soderzhanie mikroélementov i steroidnykh gormonov v krovi i tkaniakh vnutrennikh organov pri ékperimental'nom fibroze legkikh, vyzvannom vnutritrakheal'nym vvedeniem bleomitsetina.

Pulmonary fibrosis was produced in rats by intratracheal administration of bleomycetin. The development of the fibrous process in the lungs was attended by marked reduction of the zinc content in the tissues of the viscera, plasma, and formed elements of the blood, as well as of corticosterone and testosterone in blood plasma. Respiratory insufficiency is a probable cause of the developing zinc-deficiency which leads to disturbed synthesis of steroid hormones. Injection of exogenous testosterone normalizes partly the level of steroid hormones in the blood, improves the general condition of the animals, and facilitates an increase of body weight.

[The late results of marking a surgical wound of the brain with tantalum powder]. / Otdalennye resul'taty markirovki operatsionnoi rany golovnogo mozga poroshkom tantala.

Distribution in the organism of the tantalum after its application on the brain surgical wound was studied by light microscopy and atomic-emission spectrum analysis with an induction-linked plasma in patients dying from neuro oncological diseases. It is found that in all cases a partial tantalum migration into various brain regions and internal organs occurs. Blood cells are able to fix the tantalum particles in vivo and in vitro, this process being enhanced after a preceding angiography.