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The Contribution of Electrochemistry for a Better Understanding of the Degradation by Tribocorrosion of Metallic Implant Materials

Benea Lidia

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 2

547--554

EN

In this paper there are presented some results obtained by open circuit potential and electrochemical impedance spectroscopy measurements from studies performed on the behavior of tribocorrosion on metallic implant biomaterials as: 304L stainless steel, Co/nano-CeO2 nanocomposite layer and Ti6Al4V untreated and oxidized alloy to form a nanoporous TiO2 film. The open circuit potential technique used in measuring the tribocorrosion process provide information on the active or passive behavior of the investigated metallic biomaterial in the biological fluid, before, during friction and after stopping the friction. Thus it clearly show a better behavior of Co/nano-CeO2 nanocomposite coatings as compared with 304L stainless steel to tribocorrosion degradation in Hank solution; as well the better behavior of nanoporous TiO2 film formed annodically on Ti6Al4V alloy surface as compared with untreated alloy to tribocorrosion degradation in artificial saliva Fusayama Meyer. The slight decrease in polarization resistance value resulted from electrochemical impedance spectroscopy measured during friction in the case of the Co/nano-CeO2 nanocomposite layer (four times smaller), compared to 304L stainless steel, whose polarization resistance decreased more than 1000 times during friction shows the higher sensitivity of stainless steel to degradation by tribocorrosion. The same behavior is observed when comparing the polarization resistance of untreated titanium alloy recorded during friction that is about 200 hundred times smaller, while the specific polarization resistance of the oxidized alloy with the nanoporous film of titanium oxide, decreases very little during friction, highlighting the beneficial effect of modifying the titanium alloy by anodic oxidation to increase its resistance to the degradation process by tribocorrosion.

2

Simultaneous determination of celiprolol HCl and chlorthalidone in tablets and biological fluids using high-performance liquid chromatography

Belal F., El-Brashy A. M., El-Enany N., Tolba M. M

Acta Chromatographica

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2012

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Vol. 24, no. 2

185--206

EN

A simple, accurate, and sensitive reversed-phase HPLC method was developed for the simultaneous determination of celiprolol HCl (CE) and chlorthalidone (CT). Good chromatographic separation was achieved using a 250 mm × 4.6 mm i.d., 5 μm particle size Hypurity C8 column. Mobile phase containing a mixture of methanol and 0.04 M phosphate buffer (35:65, υ/υ) at pH 7.0 was pumped at a flow rate of 1.2 mL min-1 with UV detection at 225 nm. Lisinopril dihydrate (LIS) was used as internal standard. The method showed good linearity in the ranges 0.2–20 and 0.2–10 μg mL-1 with limits of detection 0.06 and 0.04 μg mL-1 and limits of quantification 0.20 and 0.14μg mL-1 for CE and CT, respectively. The suggested method was successfully applied to the simultaneous analysis of the studied drugs in their synthetic mixture and coformulated tablet. The method was further extended to the determination of CE in biological fluids. The proposed method was also applied to the determination of the studied drugs in presence of some coadministered or related drugs such as atenolol, propranolol, acetazolamide, enalapril, nicardipine, triamterene, and hydrochlorothiazide without any interference.

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Study of results of microcrystallization indices correlation in different biological fluids : experimental and clinical case

Pohodenko-Chudakova I.O., Gontchar F.L.

Engineering of Biomaterials

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2010

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Vol. 13, no. 99-101

6--7

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Zastosowanie techniki LC-MS-MS do oznaczania stężeń substancji leczniczych w materiale biologicznym

Rudzki P.J., Kobylińska K.

Przemysł Chemiczny

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2006

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T. 85, nr 5

360-362

PL

Chromatografia cieczowa połączona z tandemową spektrometrią mas (LC-MS-MS) jest jedną z częściej stosowanych technik do oznaczania stężeń substancji leczniczych w materiale biologicznym. Przybliżono podstawy teoretyczne spektrometrii mas oraz korzyści wynikające z połączenia z chromatografią cieczową. Przedstawiono zalety i wady zastosowania LC-MS-MS w badaniach farmakokinetycznych, w szczególności w badaniach równoważności biologicznej produktów leczniczych.

EN

A review covering biochem. applns. of liq. chromatography coupled with mass spectrometry, ion sources, advantages and limitations of the LC-MS-MS technique.

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Środowiskowy dym tytoniowy - skład, oddziaływanie na organizm, problemy analityczne

Demkowska I., Polkowska Ż., Namieśnik J.

Chemia i Inżynieria Ekologiczna

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2006

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Vol. 13, nr S2

229-249

PL

Palenie tytoniu jest przyczyną znacznego zanieczyszczenia powietrza wewnętrznego różnego typu pomieszczeń. Wiele związków chemicznych wydzielających się wraz z głównym i bocznym strumieniem dymu papierosowego wykazuje charakter rakotwórczy, a także wywołuje skutki toksyczne odlegle w czasie. Różny stopień narażenia na szkodliwe składniki środowiskowego dymu tytoniowego obserwuje się zarówno u aktywnych, jak i biernych palaczy. Przedstawiono przegląd informacji dotyczących technik pobierania i przechowywania próbek włosów oraz płynów biologicznych człowieka (mocz, krew, osocze krwi, surowica krwi, ślina, mleko karmiącej matki), jak również stosowanych procedur oznaczania końcowego biomarkerów ekspozycji w tychże próbkach.

EN

Tobacco smoking is an important source of indoor pollution in different enclosed spaces. Many of the compounds, which are released from mainstream and sidestream smoke of one cigarette, are toxic and cancerogenic. Exposure to ETS was evaluated in a group of both active and passive smokers. In this study useful information about collection and storage of hair and biological fluids samples was introduced. Additionally, application of suitable measuring techniques was also presented.