Katalin Zih-Perényi

Use of a new type of 8-hydroxyquinoline-5-sulphonic acid cellulose (sulphoxine cellulose) for the preconcentration of trace metals from highly mineralised water prior their GFAAS determination

Sulphoxine cellulose microcolumn was used in an FI-GFAAS system for the preconcentration of trace metals, Cd, Co, Ni, Pb and V from water and from highly mineralised water and also in the presence of complexing agent, e.g. citrate. The recovery was quantitative at pH 5 for all of the elements from NIST 1643c trace elements in water SRM and from highly mineralised water samples. No significant difference was found in the sorption of V(IV) and V(V) during preconcentration. The preparation of the 8-hydroxyquinoline-5-sulphonic acid cellulose (sulphoxine-cellulose) by Mannich reaction from aminoethyl cellulose or via chlorodeoxy and ethylenediamine cellulose is also described.

Determination of trace elements in pharmaceutical substances by graphite furnace atomic absorption spectrometry and total reflection X-ray fluorescence after flow injection ion-exchange preconcentration

Abstract Flow injection iminodiacetic acid ethyl cellulose (IDAEC) microcolumn preconcentration and graphite furnace atomic absorption spectrometry determination of trace metals (Cd, Co, Ni, Pb) were carried out without decomposition of the drug matrix. The two forms of chromium Cr(III) and Cr(VI) were separated using IDAEC and anion exchanger diethylaminoethyl (DE)-cellulose, respectively. The detection limits of trace elements in pharmaceutical substances (sugars, sorbitol, mannitol, paracetamol, amidopyrine, chloral hydrate) after a 10-fold preconcentration in 1–5% m/v solution of pharmaceuticals were in the 0.3–29 ng g −1 range. The measured concentration of trace elements in substances investigated was below 100 ng g −1 . The spike recovery was close to 100%. The capability of total reflection X-ray fluorescence technique for the determination of trace elements in pharmaceuticals with and without preconcentation was explored.

Development of atomic spectrometric methods for trace metal analysis of pharmaceuticals

Palladium, platinum and rhodium impurities were determined in pharmaceuticals by ICP-MS. The detection limits were 15, 2.8, 2.5 ng/g for palladium in enalapril maleate, platinum in calcium folinate and rhodium in levodopa, respectively. The rhodium impurity was also determined by the GFAAS method as well. ICP-MS and TXRF methods were applied for screening of other metal impurities of pharmaceuticals.

Flow-injection preconcentration and graphite furnace atomic absorption spectrometric determination of platinum.

Flow-injection graphite furnace atomic absorption spectrometric (GFAAS) methods were worked out using oxime, sulphoxine and 2,2-diamino-diethylamine (DEN) cellulose microcolumns for preconcentration of platinum after reduction by iodide or sulphite ions. The detection limits were, at 20-fold enrichment, 0.21, 0.18 and 0.30 mug l(-1), respectively. The total reflection X-ray fluorescence spectrometry (TXRF) was also used for the determination of platinum in eluates. The method was applied for the determination of platinum in salmeterol xinafoate and Ca-folinate pharmaceutical compounds. Decomposition of organic matrix of Ca-folinate was necessary before the preconcentration.

On-line preconcentration and GFAAS determination of trace metals in waters

An on-line separation preconcentration system coupled to electrothermal (graphite furnace) atomic absorption spectrometry was developed. A miniature column packed with iminodiacetic acid ethyl cellulose (IDAEC) was inserted into the loop. A peristaltic pump was used to deliver solutions. A flow of air was driven into the packed column, evacuating it between sample loading, washing and elution. The retained analyte was introduced on-line to graphite furnace using countercurrent elution with HNO 3 . The system was applied for the determination of V, Co and Pb in medicinal mineral water samples, and nickel in sea water samples. The detection limits (3σ) were 0.058, 0.022, 0.067, 0.062 μg/l for Co, Pb, V, and Ni, respectively. The R.S.D. (n = 5) was < 5% at 0.4-1.0 μg/l concentration range.

Bihor Mountains: Vărăsoaia Cave System (V5)

Vărăsoaia cave system (VCS) was discovered in 1986 in the Bihor Mountains of Western Romania, under the Padis Plateau. After countless rounds of in-cave blasting aiming to overcome some very tight passages, the cavers managed to intercept a complex karst system with several very large active (carrying underground streams) and dry galleries and reached the −653 m in depth. To date, VCS is the deepest explored cave of Romania. The network currently has over 25 km of mapped passages, but explorations are still underway. Due to floods risk and high collapse possibility in some cave sections, visiting permits are granted only to experienced cavers.

Bihor Mountains: Valea Rea Cave

Valea Rea Cave in the Bihor Mountains of Western Romania contains large chambers, passages with distinctive morphology, and abundant and beautiful speleothems in which 33 minerals were identified. We found evidences for both hypogenic and epigenic speleogenetic processes contributing to the origin of the cave. With a known length of over 16 km and a depth of 384 m, Valea Rea overshadows most of the other caves in the country, and emerges as one of the mineralogical treasure of the world.