Wyniki wyszukiwania - Biblioteka Nauki

1

Determination of diclofenac in pharmaceuticals and urine samples using a membrane sensor based on the ion associate of diclofenac with Rhodamine B

100%

Kormosh Z. , Hunka I. , Bazel Y. , Laganovsky A. , Mazurenko I. , Kormosh N.

Open Chemistry

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2007

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tom 5

|

nr 3

813-823

EN

The potentiometric response characteristics of a diclofenac selective electrode, based on ion association in different plasticizers, were compared. The sensitivity, working range, detection limit and selectivity of membrane sensors demonstrated significant dependence on the type of plasticizers. The potentiometric unit presented a linear response toward diclofenac concentrations between 1 × 10−5 − 5 × 10−2 mol L−1, with slopes of approximately 60 mV dec−1, and exhibited a response time of 3 s. The potentiometric analysis of sodium diclofenac in pharmaceutical formulations was perfomed by the membrane electrode proposed and compared with the results of potentiometric titration given by the Pharmacopoeia of Ukraine. [...]

2

Iodide Ion-Selective PVC Membrane Electrode Based on a Recently Synthesized Salen-Mn(II) Complex

100%

Shamsipur M. , Sadeghi S. , Naeimi H. , Sharghi H.

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2000

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tom Vol. 74, nr 2

231-238

EN

A new PVC mebrane electrode for iodide ions based on a recently synthesized salen-Mn9II) complex as membrane carrier was prepared. The electrode exhibits a Nernstian slope of 59.0=+0.4 mV per decade for 1- over a wide concentration range (1.0 x 10-1 --.4x 10-5M). It has a relatively fast response time of about 20 s and can be used for at least three months without any divergence in potential. The proposed sensor shows a fairly good discriminating ability towards 1- ion in comparison to other common anions. The electrode can be used in the pH range 3.5-8.5. It was used as an indicator electrode in potentiometric titration of iodide ion.

3

Thermodynamics of Substituted Pyrazolone : VI. Potentiometric and Conductometric Studies of Complexes of Some Transition Metals with 4-(4-Acetophenyl)hydrazono-3-methyl-1-phenyl-2-pyrazolin-5-one

100%

El-Bindary A. , El-Sonbati A. , Kera H.

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2000

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tom Vol. 74, nr 2

239-244

EN

The dissociation constant of 4-(4-acetophenyl)hydrazono-3-methyl-1-phenyl-2-pyrazolin-5-one (AHMPP) has been determined potentiometrically in 0.1 M KCl and 50% (v/v) ethanol-water mixture. Also, the stepwise stability constants of the formed complexes of Mn2+, Co2+, Ni2+, Cu2+, Zn2+, La3+, Ce3+, UO2+2 and Th4+ with AHMPP have been determined. The stability of the formed complexes follow the sequence: Th4+ UO2+2 Ce3+ La3+ Mn2+ Co2+ Ni2+ Cu2+ Zn2+ The thermodynamic parameters (deltaG, delta H and deltaS) for AHPP and its complexes were evaluated and discussed. The dissociation process is nonspontaneous, endothermic and entropically unfavourable. The formation of the metal complexes has been found to be spontaneous, exothermic or endothermic (depends on the metal) and entropically favourable. The stoichiometries of these complexes were determined conductometrically indicating the formation of 1:1 and 1:2 (etal:ligand) complexes.

4

Dynamic models of ion-selective electrodes with their electronic interface

100%

Wiora A. , Wiora J. , Kozyra A.

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2006

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tom Vol. 13, nr 4

421-432

EN

Dynamic models of an ion-selective electrode are analysed in this article taking into account the independence of values of its dynamic parameters from the value and direction of activity change. Unfortunately, a complicated mathematical representation of a new model makes the model difficult to be applied in practice. Therefore, some simplifications are made constructing two semi-empirical models: 1) a model with the k parameter and 2) a model basing on two other models well-known from the literature. Verifications of the new models have been performed using the measuring set-up built in the Division of Measurement Systems at the Silesian University of Technology. Obtained results proved that the model with the k parameter completely fulfils the goal of the article - its dynamic parameters are dependent on the slightest degree of the kind of activity step.

5

Oxovanadium(IV) complexes of 1-hydroxyalkane-1,1-diyldiphosphonic acids

88%

Dyba M. , Kozłowski H. , Tlałka A. , Leroux Y. , El Manouni D.

|

1998

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tom Vol. 72, nr 7

1148-1153

EN

Potentiometric and spectroscopic (EPR and UV-VIS) methods were used to study the oxovanadium(IV) complexation with several 1-hydroxyalkane-1,1-diyldiphosphonic acids. Coordination of oxovanadium(IV) to all diphosphonic ligands studied starts at very low pH and formation of the stable monomeric and trinuclear species between pH range 2-9 is observed.

6

Potentiometric determination of cysteine with thiol sensitive silver-mercury electrode

88%

Drożdż R. , Naskalski J. , Ząbek-Adamska A.

Acta Biochimica Polonica

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2007

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tom 54

|

nr 1

205-211

EN

A potentiometric procedure for cysteine thiol group concentration monitoring in media generating free radicals was developed using a thiol specific silver-mercury electrode. Electrolytic deposition of mercury on a silver wire and treatment with 20 mM cysteine in 0.5 M NaOH were used to produce the electrode. A silver-chloride electrode in saturated KCl was the reference. A glass capillary with 1 M KNO3 in 1% agarose gel was the liquid junction. The electrode responded to cysteine concentration in the range from 0.01 to 20 mM yielding a perfect linear relationship for the dependence of log [cysteine] versus electrode potential [mV], with b0 (constant) = -373.43 [mV], b1 (slope) = -53.82 and correlation coefficient r2 = 0.97. The electrode potential change per decade of cysteine concentration was 57 mV. The minimal measurable signal response was at a cysteine concentration of 0.01 mM. The signal CV amounted to 4-6% for cysteine concentrations of 0.01 to 0.05 mM and to less than 1% for cysteine concentrations of 0.5 to 20 mM. The response time ranged from about 100 s for cysteine concentrations of 0.01 to 0.1 mM to 30 s at higher cysteine concentrations. The standard curve reproducibility was the best at cysteine concentrations from 0.1 to 20 mM. In a reaction medium containing cysteine and copper(II)-histidine complex ([His-Cu]2+) solution in 55 mM phosphate buffer pH 7.4 the electrode adequately responded to changes in cysteine concentration. Beside cysteine, the silver-mercury electrode responded also to thiol groups of homocysteine and glutathione, however, the Nernst equation slope was about half of that for cysteine.

7

Analytical applications of electrode sensitive to labetalol in pharmaceuticals

88%

Gorodkiewicz E. , Falkowski P. , Sankiewicz A. , Figaszewski Z.

Open Chemistry

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2003

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tom 1

|

nr 3

242-259

EN

The analytical properties of an ion-selective electrode sensitive to labetalol with a liquid membrane, based on ion-pair complexes with sodium tetraphenylborate (TPB-Na+) are described. The studied electrode can be used for the determination of labetalol hydrochloride as a protonated form of labetalol in pharmaceuticals. The calibration curve, e.g. EMF=f(pCLabHCl) is linear in the range from 10−5 to 10−2 mol L−1 with a correlation coefficient of 0.9992 and slope of 61.13 mV/decade, which is close to the Nernstian slope. The detection limit of the examined electrode is 7.20×10−6 mol L−1. The influence of pH of the tested solutions on the formulation of the electrode is not as considerable since the electrode works correctly in the pH range 3.0–8.0. The main attributes of the developed electrode are: stability, good reproducibility of EMF and short response time, close to 30 seconds depending on labetalol concentration in the solution. The electrode shows good selectivity for many inorganic ions. The selectivity for drug cations is weaker due to the structural similarity of the interfering cations to labetalol. The results of labetalol determination using direct potentiometry in drugs such as Pressocard (Polpharma) and Trandate (GlaxoWellcome) were compatible with the quantity of labetalol declared by the manufacturer, and with parallel UV spectrophotometric and HPLC determinations.

8

Characteristics of carbon nanomaterials and their application in the construction of potentiometric sensors – review

88%

Pietrzak K. , Wardak C.

Annales Universitatis Mariae Curie-Skłodowska, sectio AA – Chemia

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2019

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tom 74

|

nr 2

EN

Carbon nanomaterials have been very popular in the scientific community in recent years, because of their unusual physical and chemical properties. Their high electrocatalytic activity, very good electrical conductivity and mechanical resistance mean that scientists are constantly looking for new technological solutions to take advantage of the opportunities offered by nanomaterials in many areas of human activity. One of such area are potentiometric sensors. There are many publications in which scientists describe methods of construction, analytical parameters and practical applications of new sensors obtained using carbon nanomaterials, and often also describe methods of synthesis of new original nanomaterials. The purpose of this work was to characterize carbon-based nanomaterials and their application in the construction of ion-selective electrodes.

9

Electrochemical Methods for Total Antioxidant Capacity and its Main Contributors Determination: A review

75%

Pisoschi A. M. , Cimpeanu C. , Predoi G.

Open Chemistry

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2015

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tom 13

|

nr 1

EN

Backround: The present review focuses on electrochemical methods for antioxidant capacity and its main contributors assessment. The main reactive oxygen species, responsible for low density lipoprotein oxidation, and their reactivity are reminded. The role of antioxidants in counteracting the factors leading to oxidative stress-related degenerative diseases occurence, is then discussed. Antioxidants can scavenge free radicals, can chelate pro-oxidative metal ions, or quench singlet oxygen. When endogenous factors (uric acid, bilirubin, albumin, metallothioneins, superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase) cannot accomplish their protective role against reactive oxygen species, the intervention of exogenous antioxidants (vitamin C, tocopherols, flavonoids, carotenoids etc) is required, as intake from food, as nutritional supplements or as pharmaceutical products. Literature study: The main advantages of electrochemical methods with respect to traditional, more laborious instrumental techniques are described: sensitivity, rapidity, simplicity of the applied analytical procedure which does not require complicated sample pre-treatment etc. The paper reviews minutiously the voltammetric, amperometric, biamperometric, potentiometric and coulometric methods for total antioxidant capacity estimation. For each method presented, the electroactivity and the mechanism of electro-oxidation of antioxidant molecules at various electrodes, as well as the influences on the electroactive properties are discussed. The characteristics of the developed methods are viewed from the perspective of the antioxidant molecule structure influence, as well as from the importance of electrode material and/or surface groups standpoint. The antioxidant molecule-electrode surface interaction, the detection system chosen, the use of modifiers, as well as the nature of the analysed matrix are the factors discussed, which influence the performances of the studied electrochemical techniques. Conclusions: The electrochemical methods reviewed in this paper allow the successful determination of the total antioxidant capacity and of its main contributors in various media: foodstuffs and beverages, biological fluids, pharmaceuticals. The advantages and disadvantages of the electrochemical methods applied to antioxidant content and antioxidant activity assay are treated and interpreted, in the case of various analysed matrixes. Combining advanced materials with classical electrode construction, provides viable results and can constitute an alternative for the future.

10

A very simple biosensing system for educational purposes

75%

Tymecki Ł. , Rozum B. , Koncki R.

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2006

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tom Vol. 51, No. 6

977-985

EN

An extremely cheap, complete bioelectrochemica! cell for potentiometric determination of urea has been described. The ceil consists of two pH-sensitive metal oxide electrodes: one of them plays a role of an internal electrode of the biosensor, whereas the second one serves as a pseudorclerencc electrode. Either enzyme or biological material containing urease has been immobilized physically by entrapment in polymer membrane. For potentiometric measurements with such a biocell, a simple and low-cost multimeter is sufficient. The proposed very simple biosensing system is useful in students' laboratory practice to illustrate several properties of biosensors, i.e. biosensitivity, dynamics, determination range, operational and storage stability, benefits of the applied immobilization methods, ere.

PL

W pracy przedstawiono bardzo prosty do wykonania system polencjometryczny do biode-tekcji mocznika. Biogniwo pomiarowe składa się z dwóch tlenkowych elektrod pl I-metrycz-nych, 7. których jedna pefni funkcje elektrody pseudoreferencyjnej, zaś druga elektrody wewnętrznej bioczujnika mocznikowego. Do uczulenia tej elektrody wykorzystano fizyczne metody immobilizacji unieruchamiając inkluzyjnie oczyszczony enzym bądź tkankowy preparat biologiczny zawierający ureazę. Stwierdzono, że do pomiarów potencjometry cznych z użyciem tak otrzymanego bioogniwa można zastosować tani miernik elektroniczny. Opisany system bioanalityczny może służyć do eksperymentalnej weryfikacji zasady działania bioczujników oraz określenia wpływu różnorodnych parametrów i czynników na charakterystyki analityczne bioczujników. Znaczącymi zaletami zaproponowanego systemu są: jego prostota, znikomy koszt oraz możliwość wykonania pracy eksperymentalnej (wytworzenie systemu analitycznego oraz badanie jego charakterystyk analitycznych) bez stosowania zaawansowanego sprzętu laboratoryjnego oraz kosztownych odczynników.

11

Interfering influence of redox reactants on potentiometric responses of electrodes with conducting polymer films

75%

Michalska A. , Nadrzycka U. , Maksymiuk K.

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2006

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tom Vol. 51, No. 6

923-938

EN

Conducting polymer (CP) films, used as ion-sensing membranes under open-circuit potcn-tiometric conditions, are highly sensitive towards redox interferents. u h ich seriously limit their analytical application. The factors affecting potential transients upon addition of redox reactant. as well as stable potentiometric responses in the presence of selected model redox reactants have been considered. The role of polymer redox capacitance and charge transfer kinetics has been studied. Theoretical predictions and experimental results obtained for polypyrrole, poly (N-me thylpyrrole), and poly(3,4-ethylenedioxythiophene) (PEDOT) in the presence of Fe(CN)63-/4- confirm a crucial role of spontaneous charging and discharging processes of CP films (e.g. polymer oxidation by dissolved oxygen, or deprotonation) for redox sensitivity. An experimental protocol utilising polarized electrode potentiometry has been developed in order to determine charging/discharging currents of the polymer in the absence and presence of added redox reactants. Polymers characterized by a significant charging/discharging rate (e.g. polypyrrole doped with perchloratc ions) have been found more resistant towards redox interferences than more stable polymers (e.g. PEDOT) with low-rate charging/discharging. This effect can be of a key importance not only for the CP-based ion-sensitive membranes, but also for conducting polymers used as ion-lo-elec-tron transducers (solid contacts) in all-solid-state ion-sclectivc electrodes.

PL

Warstwy polimerów przewodzących, stosowane jako membrany jonoczułe w warunkach potencjometry cznych, sąbardzo podatne na wpływ interferentów redoks, silnie ograniczający ich zastosowania analityczne. W pracy rozpatrywano c/.ynniki wpływające zarówno na zmiany potencjału w czasie po dodaniu reagenta redoks, jak i stabilne odpowiedzi notencjo-metryczne rejestrowane w obecności wybranych modelowych reagentów redoks. Dyskutowano również rolę pojemności redoks polimeru oraz, kinetyki przeniesienia ładunku. Przewidywania teoretyczne i wyniki eksperymentalne uzyskane dla polipiroiu, poli(N-metylopirolu) i poli(3,4-etylenodioksytiofenu) (PEDOT) w obecności układu Fe(CN)T63-/4-potwierdziły kluczową role samorzutnych procesów ładowania i rozładowania polimerów przewodzących (jak np. utlenianie polimeru tlenem z roztworu lub dcprotonowanie) dla czułości redoks. Opracowano procedurę eksperymentalną, wykorzystującą potencjomctrię z elektrodą polaryzowaną, w celu wyznaczania prądówzwiązanych z lądowaniem/rozładowaniem polimeru w nieobecności i obecności dodanego reagenta redoks. Wykazano, że polimery charakteryzujące się dużą szybkością procesu lądowania/rozładowani a {jak polipirol domieszkowany jonami chloranowymi(VH)) są odporniejsze na interferencje redoks niż bardziej trwale polimery (jak np. PEDOT) charakteryzujące się małą szybkością ładowania/rozładowania. Efekt ten ma kluczowe znaczenie nie tylko dla polimerów przewodzących pełniących role membrany jonoczułej, ale też dla polimerów stosowanych jako przetworniki jonowo-elektronowe (stale kontakty) w elektrodach jonoselektywnych pozbawionych roztworu wewnętrznego.

12

Voltammetric and potentiometric studies of some sulpha drug-Schiff base compounds and their metal complexes

75%

Ghoneim M. , Mabrouk E. , Hassanein A. , El-Attar M. , Hesham E.

Open Chemistry

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2007

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tom 5

|

nr 3

898-911

EN

The electrochemical behavior of some sulpha drug-Schiff bases at a mercury electrode was examined in the Britton-Robinson universal buffer of various pH values (2.5–11.7) containing 20% v/v) of ethanol using DC-polarography, cyclic voltammetry and controlled-potential electrolysis. The DC-polarograms and cyclic voltammograms of the examined compounds exhibited a single, 2-electron, irreversible, diffusion-controlled cathodic step within the entire pH range which is attributed to the reduction of the azomethine group-CH=N- to -CH2-NH-. The symmetry transfer coefficient (α) of the electrode reaction and the diffusion coefficient (D 0) of the reactant species were determined. The electrode reaction pathway of the compounds at the mercury electrode was suggested to follow the sequence: H+, e−, e−, H+. The dissociation constant of the sulpha drug-Schiff bases, the stability constant and stoichiometry of their complexes with various divalent transition metal ions (Mn2+, Co2+, Ni2+, Cu2+ and Zn2+) were determined potentiometrically at room temperature. [...]

13

Strontium Isopoly Tung states: Synthesis and Properties

75%

Rozantsev G. M. , Radio S. V. , Gumerova N. I.

|

2008

|

tom Vol. 82, nr 11

2067-2080

EN

By single-point pH-metric titration method we investigated the interactions in the system of Na2WO4 - HNO3 - KNO3 - H2O in the conditions that are close to equilibrium. We also showed by mathematical modeling of the processes (Newton's method, CLINP 2.1 software) that interconvertion between particular isopoly tungstate anions (ITA) takes place and this leads to the decrease in concentration of hexatungstate W6O20(OH)2 6- and hydroheptatungstate HW7O24 5- anions with simultaneous increase of quantity of paratungstate B HxW12O40(OH)2 (10-x) - and metatungstate W12O38(OH)2 6- anions in the system. The results of the modeling were proven by the successful synthesis of strontium salts with ITA. From non-equilibrium solution with different acidity Z = n(H+) / n(WO42-) we isolated strontium paratungstate B Sr5[W12O40(OH)2]ź27H2O (Z = 1.14-1.17) and strontium hydroheptatungstate Sr5[HW7O24]2ź30H2O (Z = 1.29). From the equilibrium solution the only strontium paratungstate B Sr5[W12O40(OH)2]ź27H2O (Z = 1.17-1.33) precipitates. All the salts synthesized were characterized by elemental analysis, FTIR spectroscopy, X-ray diffraction, and DTA.

14

Jonoselektywne elektrody ołowiowe ze stałym kontaktem

63%

Wardak C.

|

2010

|

tom Vol. 51, nr 6

37-39

PL

W pracy przedstawiono porównanie właściwości membranowych elektrod ołowiowych ze stałym kontaktem o różnej konstrukcji. Badano trzy typy czujników: czujnik nr 1 z wewnętrzną elektrodą wyprowadzającą Ag/AgCI i z cieczą jonową jako medium przewodzącym, czujniki nr 2 i 3 z polimerem przewodzącym odpowiednio na podłożu i węgla szklistego i złotym. W celu oceny przydatności analitycznej skonstruowanych czujników wyznaczono ich podstawowe parametry analityczne takie jak: zakres pomiarowy, nachylenie krzywej kaibracyjnej, granica wykrywalności, czas odpowiedzi, zakres pH oraz współczynniki selektywności.

EN

The potentiometric properties of membrane lead-selective electrodes with solid contact and various construction were compared. The studies were carried out with three types of sensors: sensor no 1 with Ag/AgCI as internal reference electrode and ionic liquid as conductive medium, sensors no 2 and 3 with conductive polymer deposited on glassy carbon and gold electrode respectively. The electrode basie analytical parameters, such as detection limit, linear range, slope characteristic, response time and dependence of the electrode potential on pH as well as selectivity coefficients in relation to some inorganic cations were determined. The analysis was performed by using the standard addition technique. Good recoveries were obtained in all samples.

15

Sztuczny sensor smaku, a zmysł smaku

63%

Szpakowska M. , Marjańska E.

|

2007

|

tom Vol. 60, nr 12

576-580

PL

Omówiono klasy smaku i działanie zmysłu smaku, który odgrywa ogromną rolę w ocenie jakości żywności metodami organoleptycznymi. Metody te nie są w pełni obiektywne, stąd poszukiwanie sztucznego sensora smaku. Przedstawiono szereg rozwiązań prowadzących do opracowania sensora smaku na większą skalę. Omówiono wybrane potencjometryczne i woltamperometryczne sensory smaku, a także ich handlowe modele.

EN

Taste classes and taste sense operation have been described. The sense of taste plays tremendous role in quality estimation of food products by organoleptic methods. They are not fully objective, therefore artificial taste sensor should be developed. Several solutions leading to the elaboration of taste sensor on larger scale have been presented. The selected potentiometric and voltammetric taste sensors as well as commercial models have been discussed.

16

Potentiometric determination of pKa values of some quinolones in methanol-water and acetonitrile-water binary mixtures

63%

Sardohan T. , Kir E.

|

2009

|

tom Vol. 54, No. 4

629-643

EN

pKa values of three quinolone compounds (ciprotloxacin, norfloxacin and enoxacin) in methanol—water (MeOH—water) and acetonitrile-water (ACN—water) mixtures were determined in potentiometric measurements. Standardization of the electrode system in MeOH-water and ACN-water mixtures was carried out potentiometncally by Gran's method. The obtained results were compared to the literature pKa values determined by various techniques and to the values predicted by the SPARC on-line pK 6calculator.

PL

Wyznaczono metodą potencjometryczną wartości pKa trzech związków chinolonowych: ciprofloksacyny, norfloksacyny i enoksacyny. Pomiary wykonywano w roztworach: meta-nol-woda i acetonitryl-woda. Wzorcowanie układu elektrod w układach: MeOH-woda i ACN-woda wykonano potencjometrycznie metodą Grana. Wyniki porównano z literaturowymi wartościami pK awyznaczonymi za pomocą różnych metod jak również z wartościami obliczonymi za pomocą programu SPARC.

17

Iodometric titration of sulfur compounds in alkaline medium

63%

Ciesielski W. , Zakrzewski R.

|

2006

|

tom Vol. 51, No. 5

653-678

EN

The possibilities of application of iodine as a titrant in determination of sulfur compounds have been presented. The influence of the reaction medium, the nature of compounds, and the thiol-thione tautomerism on the reaction sto ich io metry of sulfur compounds with iodine has been discussed. The conditions of volumetric titration with visual and potentio-metric end-point detection and coulometric titration with biamperometric end-point detection have been described. The advantages of the applied analytical techniques in the determination of selected sulfur compounds in fannaceutical preparations have been presented.

PL

Przedstawiono możliwości zastosowania jodu jako titrantu do oznaczania związków siarki. Omówiono wpływ środowiska reakcji, budowy cząsteczki związku oraz tautomerii tiol-tion na stechiometrię reakcji związku siarki z jodem. Opisano warunki zastosowania miareczkowania objętościowego z wizualną i potencjometryczną detekcją punktu końcowego, a także miareczkowania kulometrycznego z biamperometryczną detekcją punktu końcowego. Przedstawiono zalety stosowanych technik analitycznych do oznaczania wybranych związków siarki w preparatach farmaceutycznych.

18

Potentiometric membrane electrode for determination of nitrate based on 1,8-bis(salicylaldiminato)-3,6-dioxaoctane Ni(II) complex

63%

Mazloum Ardakani M. , Mashhadizadeh Ardakani M. H. , Karimi M. A. , Azimi M. S. , Iranpoor F. , Salvati-Niasari M.

|

2008

|

tom Vol. 53, No. 1

17-32

EN

The construction, performance, and applications of nitrate-selective electrode based on l,8-bis(salicyIaldiminato)-3,6-dioxaoctane Ni(II) complex as a carrier trapped in plasti-cized poly{ vinyl chloride) (PVC) matrix were described. The influence of membrane composition, pH, and potential interfering anions was investigated based on the response of the electrode. The electrode exhibited linear response with Nemstian slope of-58.7 š 0.7 mV per decade within the concentration range of nitrate ions of 8.0 x 10-6-1.0 mol L-1. The limit of detection was determined from the intersection of the extrapolated linear segments of the calibration plot, and equaled 8.0 x 10-6 -1.0 mol L-1. The response time of the electrode was < 15 s over the entire concentration range. The designed electrode could be used for at least three months without a significant potential drift. It exhibited good selectivity towards nitrate compared to other anions. It was applied as the indicator electrode in potentiometric determination of nitrate ions in real samples.

PL

Opisano konstrukcję, charakterystykę i zastosowania elektrody do oznaczania azotanów. Jako nośnik stosowano kompleks Ni(II) z l,8-bis(salicy!aldiminato)-3,6-dioksaoktanem w plastyfikowanym polichlorku winylu. Badano wpjyw składu membrany, pH i potencjalnie obecnych anionów na potencjał elektrody. Elektroda wykazuje nernstowskie nachylenie charakterystyki wynoszące-58,7 š 0,7 mV/dekade w zakresie stężeń 8.0 x l0-6-1.0. Granica wykrywalności wynzaczona na podstawie przecięcia liniowych odcinków krzywej kalibrowania wynosi 8.0 x 10-6 -1.0 mol L-1. Czas odpowiedzi elektrody w całym zakresie stężeń wynosi 15 s. Elektroda może być używana w ciągu co najmniej 3 miesięcy bez widocznej zmiany potencjału. Wykazuje dobrą selektywność wobec innych anionów. Elektroda została zastosowana do oznaczania azotanów w rzeczywistych próbkach.

19

Application of electrochemical sensors in determination of selected drugs

51%

Maliszewska-Mazur M. , Torbicz W.

|

tom Vol. 26, no. 4

39-46

EN

Precise and cheap methods for fast detection of drugs for the purposes of administration of appropriate medication are of paramount importance in clinical practice. Nowadays, many pharmaceutics with a high toxicity and narrow margin of safety are applied, so they should be delivered very precisely. Electrochemical methods have been used to determine the concentration of benzodiazepines, phenothiazines and paracetamol types of drugs. These drugs were widely tested, and their electrode reactions, dependences on the medium parameters and metabolism are known. These data may be the basis for the development of biosensors for the above mentioned drugs.

20

Potencjometryczna metoda oznaczania niskiej zawartości chlorków w matrycach glinokrzemianowych

51%

Sołtysik B.

|

2009

|

tom nr 2

6-10

PL

W dostępnej literaturze krajowej oraz zagranicznej brakuje prac natematmetod oznaczania zawartości chlorków w materiałach krzemianowych. Celem niniejszej pracy było przebadanie potencjometrycznej metody oznaczania niskiej zawartości oznaczania chlorków w próbkach stałych o matrycy glinokrzemianowej.