Eine neue Methode zur maßanalytischen Bestimmung von Kalium nach Fällung als Kaliumtetraphenylborat

Flaschka, H.; Amin, A. M.; Holasek, A.

doi:10.1007/bf00460978

Cited by 13 publications

(3 citation statements)

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“…beaker. The samples contained between 4 and 36 mg. of potassium. A potential of +0.080 volt vs. the reference electrode was applied to the dropping mercury electrode.…”

Section: Exploratory Experimentsmentioning

confidence: 99%

Amperometric Titration of Potassium with Sodium Tetraphenylborate

Amos¹,

Sympson²

1959

Anal. Chem.

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An amperometric method can b e used for detecting the end point in the direct titration of potassium with a standard solution of sodium tetraphenylborate. The anodic depolarization current of tetraphenylborate at a dropping mercury electrode is measured at intervals throughout the titration. The method gives good results for the titration of potassium in the concentration range of 2.2 x 1 0-3 to 2.0 X 10-2M. Chloride interferes at concentrations of 0.32M or higher. INCE Kittig, Keicher, Ruckert, and S Raff (21) reported that the tctraphenylborate ion quantitatively precipitates potassium ion in aqueous solution, numerous procedures for the determination of potassium based on the precipitation reaction have been described. No attempt is made to refer to all of these determinations in this article. Most of the volumetric methods published have been indirect methods of two general types. One technique is to precipitate potassium by the addition of excess sodium tetraphenglborate. The precipitate is collected and dissolved in an organic solvent. The dissolved tetraphenylborate is then determined by one of several titration procedures (2-6, 16, 18). The second method is to add an excess of standard tetraphenylborate solution to a solution of potassium ion. The precipitate is filtered off, and the excess tetraphenylborate in the filtrate is determined by titration with a second standard solution (8, 17, 15, 20).Four methods for the direct titration of potassium with standard tetraphenylborate have been described. Raff and Brotz (15) determined potassium by a conductometric titration using a standard lithium tetraphenylborate solution. In a modification of this method sodium tetraphenylborate was used as the titrant ( 7 ) . Lane (12) has reported a high frequency titration of potassium with tetraphenylborate. Conductometric titrations cannot be applied to solutions containing high concentrations of electrolytes not involved in the titration reaction. Kirsten, Berggren, and Xilsson (5) have reported the potentiometric titration of potassium nitrate with standard tetraphenylborate using a silver metal indicator electrode. This technique would, of course, require dropwise addition of the titrant in the vicinity of the end point. The potential break a t the end point did not appear to be as sharp as desirable.The purpose of this investigation was to develop another method for detecting the end point in the direct titration of potassium with sodium tetraphenylborate. This would eliminate certain additional steps in the analysis, such as filtrations and back-titrations. It was known that mercury(I1) forms a very insoluble precipitate with tetraphenylborate (10,21). This suggested that the tetraphenylborate ion should give an anodic polarographic wave a t a dropping mercury electrode due to the depolarization of the dropping mercury electrode by the tetraphenylborate. If a potential, corresponding to some point on the anodic wave of tetraphenylborate, were applied to a dropping mercury electrode immersed in a potassium solu...

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“…beaker. The samples contained between 4 and 36 mg. of potassium. A potential of +0.080 volt vs. the reference electrode was applied to the dropping mercury electrode.…”

Section: Exploratory Experimentsmentioning

confidence: 99%

Amperometric Titration of Potassium with Sodium Tetraphenylborate

Amos¹,

Sympson²

1959

Anal. Chem.

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“…Berkhout (9) described a modification of the method of Raff and Brotz (112) which precipitates potassium as a salt of tetraphenylboron. Procedures were described by Flaschka, Amin, and Holasek (36) and Rudorff and Zannier (120, 121), wrho titrated potassium tetraphenylborate iodometrically. A volumetric method depending on iodometric titration of potassium diliturate with copper sulfate was studied by Press and Murray (106).…”

Section: Potassiummentioning

confidence: 99%

Review - Fertilizers

Bridger¹

1955

Anal. Chem.

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“…Flaschka (19) and R&dorff and Zannier (46) recommended pHs of 4 to 6 and 5 to 6, respectively, with precipitation taking place at 60° to 80° C. so as to increase particle size of the precipitate.…”

Section: Degradation Of Micaceous Mineralsmentioning

confidence: 99%

Degradation of soils and micaceous minerals by the removal of potassium with sodium tetraphenylboron

Hunziker

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Eine neue Methode zur maßanalytischen Bestimmung von Kalium nach Fällung als Kaliumtetraphenylborat

Cited by 13 publications

References 1 publication

Amperometric Titration of Potassium with Sodium Tetraphenylborate

Amperometric Titration of Potassium with Sodium Tetraphenylborate

Review - Fertilizers

Degradation of soils and micaceous minerals by the removal of potassium with sodium tetraphenylboron

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