Metallothionein induction in Littorina littorea (Mollusca: Prosobranchia) on exposure to cadmium

1992 ◽  
Vol 72 (2) ◽  
pp. 329-342 ◽  
Author(s):  
M.J. Bebianno ◽  
W.J. Langston ◽  
K. Simkiss
Keyword(s):  
Digestive Gland ◽  
Metal Binding ◽  
De Novo ◽  
Differential Pulse ◽  
Littorina Littorea ◽  
Differential Pulse Polarography ◽  
Tissue Preparation ◽  
Surrounding Water ◽  
Pulse Polarography ◽  
Intertidal Gastropod

Cadmium uptake, storage and metabolism has been studied in the digestive gland and remaining tissues of the intertidal gastropod Littorina littorea (L). Accumulation of cadmium was linear with time in both of these compartments in individuals exposed to a range of cadmium concentrations (4, 40 and 400 μg Cd l−1).The subcellular distribution of cadmium in the digestive gland and remaining tissues of Littorina littorea reveals that most of the metal is bound to metallothionein, even in controls, and that cadmium associated with metallothionein increases in proportion to cadmium concentrations in the surrounding water.Measurements of metallothionein, made by differential pulse polarography showed that, in the digestive gland, concentrations of this metal-binding protein are not significantly affected by cadmium exposure, while in the remaining tissues they are dose-related.The inherently high levels of metallothionein in the digestive gland of L. littorea explain the role of this tissue as a major site for cadmium storage. However, the lack of significant de novo synthesis of metallothionein in response to cadmium, together with polarographic interferences from high molecular weight thiolic proteins, reduces the value of this tissue preparation as a means of detecting sublethal responses to metals.

Induction of Metallothionein Synthesis in the Gill and Kidney of Littorina Littorea Exposed to Cadmium

1995 ◽  
Vol 75 (1) ◽  
pp. 173-186 ◽  
Author(s):  
M.J. Bebianno ◽  
W.J. Langston
Keyword(s):  
Molecular Weight ◽  
Metal Binding ◽  
Gel Filtration ◽  
Biological Response ◽  
Differential Pulse ◽  
Molar Ratio ◽  
Littorina Littorea ◽  
Differential Pulse Polarography ◽  
Steady State Condition ◽  
Field Samples

Induction of metallothionein synthesis in Littorina littorea exposed to cadmium (400 µg I-1) is tissue dependent. Concentrations of the metal-binding protein increased by a factor of four in the gills and by a factor of three in the kidney.Gel filtration chromatography of heat-treated cytosolic extracts reveals that cadmium, accumulated in both the gills and the kidney, is bound principally to the newly formed metallothionein. Cadmium saturation of the protein (at an MT:Cd molar ratio of 1:5) and the approach of steady-state condition for Cd accumulation was indicated in the latter tissue, but there was little evidence for Cd equilibrium in gills.Metallothionein levels in the kidney of L. littorea can be determined on a routine basis in laboratory experiments and in field samples by differential pulse polarography of wholecytosol preparations: heat-treatment/centrifugation is sufficient to remove most of the interference from high-molecular-weight thiolic proteins. In contrast, the use of gelfiltration chromatography is recommended alongside polarographic analysis of the gill cytosol to enable quantification of, and compensation for, such interferences, and hence to ensure that only metallothionein is determined.Measurements of metallothionein induction in the kidney of Littorina may therefore prove useful in the determination of sublethal biological response to metal contamination. Background metallothionein concentrations of 3–4 mg g-1 (measured polarographically) serve as a baseline against which samples from contaminated sites can be assessed.INTRODUCTIONExposure of marine organisms to metals such as cadmium can induce the synthesis of low molecular weight, cysteine-rich proteins, metallothioneins (MTs), which are capable of sequestering and detoxifying excess intra-cellular metal.

Determination of platinum in biological material by differential pulse polarography: Analysis in urine, plasma and tissue following sample combustion

1983 ◽  
Vol 48 (10) ◽  
pp. 2903-2908 ◽  
Author(s):  
Viktor Vrabec ◽  
Oldřich Vrána ◽  
Vladimír Kleinwächter
Keyword(s):  
Biological Material ◽  
Biological Fluid ◽  
Mercury Electrode ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Linear Calibration ◽  
Catalytic Current ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode

A method is described for determining total platinum content in urine, blood plasma and tissues of patients or experimental animals receiving cis-dichlorodiamineplatinum(II). The method is based on drying and combustion of the biological material in a muffle furnace. The product of the combustion is dissolved successively in aqua regia, hydrochloric acid and ethylenediamine. The resulting platinum-ethylenediamine complex yields a catalytic current at a dropping mercury electrode allowing to determine platinum by differential pulse polarography. Platinum levels of c. 50-1 000 ng per ml of the biological fluid or per 0.5 g of a tissue can readily be analyzed with a linear calibration.

Polarography of N,N-dimethyl-4-amino-4'-hydroxyazobenzene in water-methanol mixtures

1985 ◽  
Vol 50 (3) ◽  
pp. 712-725 ◽  
Author(s):  
Jiří Barek ◽  
Lubomír Kelnar
Keyword(s):  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Reduction Mechanism ◽  
Pulse Polarography ◽  
Methanol Medium

The polarographic reduction of N,N-dimethyl-4-amino-4'-hydroxyazobenzene in water-methanol medium was investigated. Evidence is presented for adsorption of the depolarizer on the electrode, and a reduction mechanism is proposed. Conditions are indicated for the determination of this compound in the concentration range 10-4-10-6 mol/l by d.c. polarography, 10-5 to 3 . 10-7 mol/l by Tast polarography, and 10-5-3 . 10-8 mol/l by differential pulse polarography.

Polarographic and voltammetric determination of 6-mercaptopurine and 6-thioguanine

1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima
Keyword(s):  
Detection Limit ◽  
Differential Pulse Voltammetry ◽  
Detection Limits ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Differential Pulse Polarography ◽  
Hanging Mercury Drop Electrode ◽  
Pulse Polarography ◽  
Pulse Voltammetry

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.

The polarographic and voltammetric determination of 2,6-dicyano-4-nitro-2'-acetylamino-4'-diethylaminoazobenzene

1990 ◽  
Vol 55 (6) ◽  
pp. 1508-1517 ◽  
Author(s):  
Jiří Barek ◽  
Dagmar Civišová ◽  
Ashutosh Ghosh ◽  
Jiří Zima
Keyword(s):  
Azo Dye ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Determination Limit ◽  
Polarographic Reduction ◽  
Hanging Mercury Drop Electrode ◽  
Optimal Conditions ◽  
Pulse Polarography ◽  
Pulse Voltammetry

The polarographic reduction of the title azo dye was studied and optimal conditions were found for its analytical utilization in the concentration range 1 . 10-6 - 1 . 10-7 mol l-1 using differential pulse polarography and 1 . 10-6 - 1 . 10-8 mol l-1 using fast scan differential pulse voltammetry or linear scan voltammetry at a hanging mercury drop electrode. When the latter technique is combined with adsorptive accumulation of the studied substance on the surface of the hanging mercury drop, the determination limit can be further decreased to 3 . 10-9 mol l-1.

Polarographic and voltammetric determination of N,N’-dinitrosopiperazine

1991 ◽  
Vol 56 (7) ◽  
pp. 1434-1445 ◽  
Author(s):  
Jiří Barek ◽  
Ivana Švagrová ◽  
Jiří Zima
Keyword(s):  
Mercury Electrode ◽  
Linear Sweep Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Polarographic Reduction ◽  
Concentration Region ◽  
Pulse Polarography ◽  
Chemical Efficiency ◽  
Dropping Mercury Electrode

Polarographic reduction of the genotoxic N,N’-dinitrosopiperazine was studied and its mechanism was suggested. Optimum conditions were established for the determination of this substance by tast polarography over the concentration region of 1 . 10-3 to 1 . 10-6 mol l-1 and by differential pulse polarography on the conventional dropping mercury electrode or by fast scan differential pulse voltammetry and linear sweep voltammetry on a hanging mercury drop electrode over the concentration region of 1 . 10-3 to 1 . 10-7 mol l-1. Attempts at increasing further the sensitivity via adsorptive accumulation of the analyte on the surface of the hanging mercury drop failed. The methods are applicable to the testing of the chemical efficiency of destruction of the title chemical carcinogen based on its oxidation with potassium permanganate in acid solution.

Determination of Organic Bases by Ion-Pair Extraction Polarography Using Orange II as Counter Ion

1992 ◽  
Vol 57 (11) ◽  
pp. 2272-2278 ◽  
Author(s):  
Václav Koula ◽  
Daria Kučová ◽  
Jiří Gasparič
Keyword(s):  
Model Compound ◽  
Differential Pulse ◽  
Ion Pair ◽  
Differential Pulse Polarography ◽  
Orange Ii ◽  
Organic Bases ◽  
Counter Ion ◽  
Pulse Polarography ◽  
Ammonium Compounds

The combination of ion-pair extraction and differential pulse polarography is shown to be a method suitable for the determination of 10-7 mol l-1 concentrations of organic bases of quaternary ammonium compounds. Orange II (4-[2-hydroxy-1-naphtyl]azobenzenesulfonic acid) was found to be an appropriate polarographically active counter-ion. The proposed method was used for the determination of tetrapentylammonium bromide (as model compound), Septonex ([1-(ethoxycarbonyl)-pentadecyl]trimethylammonium bromide) and codeine.

Polarographic Determination of 6-β-D-Glucopyranosyloxy-7-hydroxycoumarin

1996 ◽  
Vol 61 (3) ◽  
pp. 333-341
Author(s):  
Jiří Barek ◽  
Roman Hrnčíř ◽  
Josino C. Moreira ◽  
Jiří Zima
Keyword(s):  
Natural Compound ◽  
Mercury Electrode ◽  
Direct Determination ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Whitening Agent ◽  
Polarographic Behaviour ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode

The polarographic behaviour was studied for 6-β-D-glucopyranosyloxy-7-hydroxycoumarin, a natural compound serving as an optical whitening agent. The substance can be quantitated by tast polarography, differential pulse polarography using a conventional dropping mercury electrode, and differential pulse polarography using a static mercury drop electrode over the regions of 20-1 000, 2-1 000, and 0.2-1 000 μmol l-1, respectively. The methods developed for the quantitation of the compound were applied to its direct determination in a raw product.

Polarographic and Voltammetric Determination of Trace Amounts of 3-Nitrofluoranthene

2006 ◽  
Vol 71 (11-12) ◽  
pp. 1571-1587 ◽  
Author(s):  
Karel Čížek ◽  
Jiří Barek ◽  
Jiří Zima
Keyword(s):  
River Water ◽  
Solid Phase ◽  
Mercury Electrode ◽  
Stripping Voltammetry ◽  
Differential Pulse ◽  
Differential Pulse Polarography ◽  
Pulse Polarography ◽  
Dropping Mercury Electrode ◽  
Separation And Preconcentration

The polarographic behavior of 3-nitrofluoranthene was investigated by DC tast polarography (DCTP) and differential pulse polarography (DPP), both at a dropping mercury electrode, differential pulse voltammetry (DPV) and adsorptive stripping voltammetry (AdSV), both at a hanging mercury drop electrode. Optimum conditions have been found for its determination by the given methods in the concentration ranges of 1 × 10-6-1 × 10-4 mol l-1 (DCTP), 1 × 10-7-1 × 10-4 mol l-1 (DPP), 1 × 10-8-1 × 10-6 mol l-1 (DPV) and 1 × 10-9-1 × 10-7 mol l-1 (AdSV), respectively. Practical applicability of these techniques was demonstrated on the determination of 3-nitrofluoranthene in drinking and river water after its preliminary separation and preconcentration using liquid-liquid and solid phase extraction with the limits of determination 4 × 10-10 mol l-1 (drinking water) and 2 × 10-9 mol l-1 (river water).

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