Određivanje kadmija u vinu atomskom apsorpcijskom spektrometrijom

The objective of the present investigation was to develop a bilayer-floating tablet (BFT) for captopril using direct compression technology. HPMC, K-grade and effervescent mixture of citric acid and sodium bicarbonate formed the floating layer. The release layer contained captopril and various polymers such as HPMC-K15M, PVP-K30 and Carbopol 934p, alone or in combination with the drug. The floating behavior and in vitro dissolution studies were carried out in a USP 23 apparatus 2 in simulated gastric fluid (without enzyme, pH 1.2). Final formulation released approximately 95% drug in 24 h in vitro, while the floating lag time was 10 min and the tablet remained floatable throughout all studies. Final formulation followed the Higuchi release model and showed no significant change in physical appearance, drug content, floatability or in vitro dissolution pattern after storage at 45 oC/75% RH for three months. Placebo formulation containing barium sulphate in the release layer administered to human volunteers for in vivo X-ray studies showed that BFT had significantly increased the gastric residence time.Opisana je izravna metoda određivanja kadmija u uzorcima vina elektrotermičkom atomskom apsorpcijskom spektrometrijom (ETAAS). Za atomizaciju su upotrebljene pirolitičke grafitne cjevčice i grafitne cjevčice sa standardnom pirolitičkom platformom po L’vovu. Granica određivanja bila je 0,08 microg L1 kadmija. Relativna standardna devijacija za koncentracijsko područje od 0,2 do 10 g L-1 bila je između 1 i 7%. Točnost metode potvrđena je usporedbom rezultata s rezultatima dobivenih iz vlažno digeriranih uzoraka i spiked uzoraka. Pomoću ove metode određeno je da se koncentracija kadmija u makedonskim vinima kreće u rasponu od 0,10 do 0,90 microg L-1

Svojstva bakar(II)-histidin kompleksa izoliranog iz dijalizirane humane plazme s histidinom

The copper(II)-histidine complex obtained following dialysis of human plasma with histidine was investigated using various types of extraction systems and ion exchange resins. According to the results obtained, the Cu(II)-histidine complex formed under the dialysis conditions has one positive charge. Preconcentration of copper from the dialysis solution was achieved by its extraction as a dithiocarbamate complex and by sorption on cation-exchange resin or onto chelate sorbent.U radu su ispitivani različiti sustavi za ekstrakciju i ionske-izmjenjivačke smole za izolaciju bakar(II)-histidin kompleksa iz dijalizirane humane plazme s histidinom. Prema dobivenim rezultatima, bakar(II)-histidin kompleks ima jedan pozitivan naboj. Prekoncentracija bakra iz otopine za dijalizu postignuta je ekstrakcijom ditiokarbamatnog kompleksa i sorpcijom na kation-izmjenjivačku smolu ili stvaranjem kelata

In Vitro Evaluation of a Stable Monomeric Gold(II) Complex with Hematoporphyrin IX: Cytotoxicity against Tumor and Kidney Cells, Cellular Accumulation, and Induction of Apoptosis

The antineoplastic potential of a stable monomeric Au(II) complex with hematoporphyrin IX (Hp), namely [Au(II)Hp−2H.(H2O)2], was investigated in a panel of tumor cell lines. The complex exhibits strong cytotoxicity, whereby the leukaemia- and lymphoma-derived cell lines are more sensitive, with IC50 values comparable to those of the reference anticancer drug cisplatin. In contrast, the solid tumor models are more sensitive to the platinum drug. A comparative assessment of both agents against the human kidney cell line 293T has shown that [Au(II)Hp−2H.(H2O)2] is less cytotoxic. The gold complex induces oligonucleosomal DNA fragmentation in tumour cells following 24-hour treatment and hence its cytotoxic effect is at least partly mediated by induction of apoptotic cell death. A prominent intracellular gold accumulation was detected after treating tumor cells with [Au(II)Hp−2H.(H2O)2] which shows that its putative pharmacological targets are readily accessible after a short incubation period

Preconcentration Methods for Determination of Thallium in Natural Waters

Two preconcentration procedures for electrothermal atomic absorption (ETAAS) determination of thallium in mineral, spring, tap, river, underground and sea water were developed and compared: (i) Column solid phase extraction with new sandwich type disposable sorbent columns

Arsenic, cadmium and lead in medicinal herbs and their fractionation

Arsenic, cadmium and lead were determined for quality control monitoring purposes of Bulgarian herbs and their infusions by inductively Coupled plasma mass spectrometry and electrothermal atomic absorption spectrometry. Twelve samples of yarrow (Achillea millefolium), 18 of chamomile (Flores Chamomillae), 8 of bearberry leaves (Folia uvae ursi), 24 of peppermint (Mentha piperitoe folium), 10 of hibiscus (Hibiscus sabdariffa), 14 of oregano (Origanum vulgare) and 12 of thyme (Thymus serpyllum) were analyzed. The studied toxic elements were present in the medicinal plants (12-225 mu g/kg As, 15-268 mu g/kg Cd, 0.2-8.6 mg/kg Pb). Arsenic was found in all herbal infusions at levels up to 0.4 mu g/l. Cadmium was present in infusion!; of chamomile, hibiscus, peppermint and thyme at levels Lip to 0.7 mu g/l. Lead was detected only in hibiscus infusions (2-3 mu g/l). It was established that the major part of arsenic and lead in herbal infusions existed in biomacromolecular fraction. Cadmium appears to be present mainly in cationic form at pH 1 (stomach acidity), but at pH 7.6 (intestine acidity) there is a non-cationic fraction as well