Bromide ion selective electrode

Bromide ion-selective electrodes These electrodes have important applications in the determination of Br" in waters [437], in blood plasma [70,308] and in rocks [7,81]. Br" ISEs are suitable for studying the oscillating Zhabotinsky... 

Reliability of Bromide Ion-Selective Electrodes for Studying the Oscillatory Belouzov-... 

A knowledge of blood bromide levels is occasionally important as in patients treated with bromosedatives, or anaesthetised with halothane or suffering from drug abuse. The normal bromide level in serum is less than 0.1 mmol dm but in cases of bromide intoxication can rise to above 40 mmol dm and both levels are measurable by the bromide ion-selective electrode as long as the bromine is... 

The quaternary ammonium salts (QAS) are widely used as ionofores of ion-selective electrodes and extractants of metals halogenic anion complexes. The influence of the QASes nature with various methyl groups contents on the cadmium extraction from bromide media has been investigated. 

KOrOs and M. Burger, Bromide selective electrode for use in following the Zhabotindu-type oscillating chemical reaction, in Ion-Selective Electrodes (ed. E Pungor), Symposium 1972, Akademiai Kiad6, Budapest (1973), p. 191. Koryta,y4na/. Chim. Acta 61, 329 (1972). 

In the method proposed by van Staden for the determination of three halides, these are separated in a short colunm packed with a strongly basic ion-exchange resin (Dowex i-X8) that is placed in an FI manifold. A laboratory-made tubular silver/silver halide ion-selective electrode is used as a potentiometric sensor. Van Staden compared the response capabilities of the halide-selective electrodes to a wide concentration range (20-5000 pg/mL) of individual and mixed halide solutions in the presence and absence of the ion-exchange column. By careful selection of appropriate concentrations of the potassixun nitrate carrier/eluent stream to satisfy the requirements of both the ion-exchange column and the halide-selective electrode, he succeeded in separating and determining chloride, bromide and iodide in mixed halide solutions with a detection limit of 5 /xg/mL [130]. 

The potentiometric determination of bromide anions with ion-selective electrodes is possible with commercial electrodes that are commonly based on solid Ag2S—AgBr ion conductor membranes [148-150]. Recently, a novel liquid film sensor has been proposed by Ganjali etal. [151] Determination of bromide was reliable without significant interference from common ions such as chloride and iodide, and was reported down to a micromolar level. The electroactive species in the liquid membrane... 

The determination of iodide with ion-selective electrodes is possible with commercial sensors often based on ion conducting Ag2S—Agl solid membranes [57]. A PVC membrane-based sensor employing a silver complex with thiourea derivatives has been reported by El Aamrani et al. [202]. Interference from thiocyanate and bromide was investigated and a limit of detection in the nanomolar range was determined. A study assessing the performance... 

Fig. 1. Simultaneous separation and detection of anions and cations on a latex agglomerate column. Column Dionex HPIC-CS5 cation exchange column (250X2 mm) with precolumn HPIC-CG5 (50 X 4 mm) eluent 0.5 mM copper sulfate, pH 5. 62 flow rate 0.5 ml/min sample volume 20 gl containing 0.1 m M of each ion detection two potentiomet-ric detectors equipped with different ion-selective electrodes in series. Peaks (1) chloroacetate, (2) chloride, (3) nitrite, (4) benzoate, (5) cyanate, (6) bromide, (7) nitrate, (8) sodium, (9) ammonium, (10) potassium, (11) rubidium, (12) cesium, (13) thallium. Reprinted with permission from [10].

Akaiwa et al. [324] have used ion exchange chromatography on hydrous zirconium oxide, combined with detection based on direct potentiometry with an ion selective electrode, for the simultaneous determination of chloride and bromide in non saline waters. 

In measurements with ion-selective electrodes, interference by other ions is expressed by selectivity coefficients as in Eq. (17). If the nature of the ion-selective membrane is known, these interferences may easily be estimated. For example, in the determination of chloride with a Cl -selective electrode containing AgCl as the electroactive component in its membrane, concentrations of bromides or iodides (generally X ) must be controlled because they form less soluble silver salts than AgCl the solubility products of corresponding silver halides are used in Eq. (20) to estimate the selectivity coefficient ... 

Potentiometric detection of anions is feasible when an electrode is available that responds quickly, reversibly and reproducibly to the concentration (or more precisely to the activity) of sample ions. It is often possible to detect a given ion or class of ions with excellent selectivity. For example, solid-state or crystalline ion selective electrodes have been used in IC to detect halide anions. The fluoride ion-selcclivc electrode is particularly selective [20,21]. A copper wire electrode has been used to detect anions such as iodate, bromide and oxalate [22]. 

Electrodes suitable for the potentiometric determination of surfactants are either specially designed liquid or solid membrane electrodes or ion-selective electrodes that in addition to being selective to a particular ion, also quantitatively respond to surfactants. For example, a nitrate ion-selective electrode responds to anionic surfactants, a calcium ion-selective electrode is sensitive to quaternary ammonium salts, and a barium ion-selective electrode can be used for assaying polyethoxylates [43], In some cases it is possible for one to perform potentiometric determination of a counter-ion, e.g. one can titrate alkylpyridinium chloride or bromide salts with silver nitrate solution using silver wire as an indicator electrode [38]. 

The selectivity coefficient of an iodide ion-selective electrode for bromide ion is to be determined using the equation derived in problem 14, above. An iodide ion-selective electrode and an appropriate reference dec-trode are equilibrated in 50.0 ml of 1.00 x 10" MKI at 25°C. The equilibrium potential is -130.2 mV. Then, 0.50-, 1.00-, 2.00-, and 2.00-ml aliquots of 1.00 M KBr are added sequentially. After each addition, the equilibrium potential is measured -131.5, -133.9, -137.5, and -140.8 mV, respectively. Determine the selectivity coefficient for bromide ion if the slope of the calibration curve for iodide is 59.2 mV/ decade. What assumptions have been made in this approach ... 

The application of potentiometric detection in ion-chromatography is favoured by the progress in the field of membrane ion-selective electrodes (ISE). The electrodes with solid-state membranes were mostly employed for determination of halides, pseudohalides and some other anions binding silver ions. The use of fluoride electrode in multidetector, chromatographic system offers very low detection limit of 1.2 ng fluoride in injected samples. Application of bromide electrode in the same system provides even five-fold better detectability. The same level of detectability was reported by Butler and Gershey for iodide with iodide ISE. In the system with preconcentration step the detectability can be lowered by an order... 

Body fluids are complicated mixtures whose inorganic electrolyte composition in plasma and muscle cells is normally fairly constant, but which may show considerable variations in gastric and pancreatic juices, sweat, saliva and urine. Ion-selective electrodes are the only devices capable of measuring the important normal ions and dissolved gases in fluids and they have proved particularly useful for medical, biochemical and physiological investigations of calcium, potassium, sodium, ammonium, chloride and fluoride. To a lesser extent, the electrodes have been used for bromide, iodide, lead, carbon dioxide, enzymes, proteins and in metal—nucleotide systems. 

In potentiometric methods, the potential between a reference and an indicator electrode is measured, which corresponds to the analyte activity. Because of their usefulness in food analysis, ion-selective electrodes (ISEs) that measure anions like bromide, chloride, and fluoride or cations like potassium, sodium, and calcium stand out among indicator electrodes. The characteristics and advantages of ISE include the ability to measure different anions and cations directly, the fact that they do not consume the analyte, the fact that analyses are independent of sample volume when taking direct measurements, and that moreover turbidity, color, and viscosity do not affect the measurement. Potentiometric methods are also... 

Ion-selective electrodes (ISEs) are potentiometric sensors that include a selective membrane to minimize matrix interferences. The most common ISE is the pH electrode, which contains a thin glass membrane that responds to the H concentration in a solution. Other parameters that can be measured include fluoride, bromide, nitrate, and cadmium, and gases in solution such as ammonia, carbon dioxide, nitrogen oxide, and oxygen. ISEs do have their limitations including lack of selectivity and sensitivity and problems connected with conditioning of electrodes. Detection limits for nitrate-N, for example, are typically 0.098mgl for commercial field devices and have chloride as a major interferent. 

The measurements were performed on alkyltrimethylammonium bromides, RN (CH2)3 Br with R = octyl, decyl, dodecyl, tetradecyl and hexadecyl. These detergents were selected because they are easily synthesized and because commercially available bromide ion specific electrodes can be used to probe their micelle forming properties. 

Noszticzius, Z. Noszticzius, E. Schelly, Z. A. 1983. On the Use of Ion-Selective Electrodes for Monitoring Oscillating Reactions. 2. Potential Response of Bromide-and Iodide-Selective Electrodes in Slow Corrosive Processes. Disproportionation of Bromous and lodous Acid. A Lotka-Volterra Model for the Halate Driven Oscillators, J. Phys. Chem. 87, 510-524. 

Noszticzius, Z. Wittman, M. Stirling, P. 1984b. A New Bromide-Selective Electrode for Monitoring Oscillating Reactions, in 4th Symposium on Ion-Selective Electrodes, Mdtaftired. Elsevier Amsterdam pp. 579-589. 

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