Conductometric determination of quaternary ammonium salts by sodium perchlorate and vice versa

A conductometric method is proposed for the determination of quaternary ammonium salts (chloride or bromide), based on the poor solubility of the relative perchlorates. A comparison between expected and found values shows that the method is suitable, rapid, and easy for quantities in the range from 0.2 to 5 g. The error depends on the solubility of the relative perchlorate. The apparent and tentative solubility product of the studied compounds were calculated. The obtained values allowed to propose benzyltributyl ammonium chloride (BTBA Cl) as precipitant for the conductometric titration of perchlorate. This easy, rapid and accurate determination can be used to analyze the perchlorate ion even in concentrated solutions and to determine stability constants for complex formation in aqueous solutions. Received: 11 June 1997 / Revised: 8 October 1997 / Accepted: 11 October 1997     

Immobilization of quaternary ammonium salts on silica gel for perchlorate ions removal

Silica surface was modified with quaternary ammonium salts to give three matrices of different chain length. The synthesized supports were characterized by elemental analysis and infrared spectroscopy, as well as scanning electron microscopy and semi-empirical parametric method 5. Their exchange capacities for ClO₄ ⁻, F⁻, NO₃ ⁻ and CH₃COO⁻ ions were investigated by conductometric titration. The amount of exchanged chloride ions from the matrix was studied for different initial anions concentration. The functionalized silica gel showed very good ability of perchlorate ions exchange from the water solution in room temperature. The anion-exchange properties were also studied in comparison to different number of reactive sites in the matrices. The increased number of chloride at the silica surface took effect on increased ability of ClO₄ ⁻ anion exchange      

Simultaneous determination of bromide and iodide ions by capillary isotachophoresis using quaternary ammonium salts

Bromide and iodide ions were determined simultaneously by capillary isotachophoresis using an aqueous electrolyte system; the separation principle was based on the ion-pairing equilibria between tetradecyldimethylbenzylammonium ion and these anions in the leading electrolyte. The interaction between iodide ion and tetradecyldimethylbenzylammonium ion was stronger than that for bromide ion. Thus complete separation of bromide and iodide ions could be obtained by using a leading electrolyte containing 1.5 mM tetradecyldimethylbenzylammonium ion. The pH of the leading electrolyte was adjusted to 5.0. The relative standard deviations of the zone length for bromide and iodide ions were 1.1 and 1.2%, respectively, when mixture of 3.0 mM of these ions was analysed. A 150-μl volume could be injected for the simultaneous determination of low concentrations of bromide and iodide ions.     

Synthesis of bunte salts from 1,2-benzisothiazol-3-ones and vice versa

1,2-Benzisothiazol-3-ones undergo ring-opening when treated with sodium hydrogen sulphite solution, giving Bunte salts, reconversion of which to benzisothiazol-3-ones can be effected with dilute alkali.     

离子对分离和抑制电导检测法测定四乙基铵和四丁基铵根离子

建立了季铵盐的离子色谱分析方法.采用Dionex DX-500 型离子色谱仪,C18柱,电导检测器,以30%乙腈和10 mmol/L甲烷磺酸混合溶液为流动相,流量为1.00 mL/min.四乙基溴化铵和四丁基溴化铵的质量浓度和峰面积的相关系数分别为0.9996和0.9994;线性范围分别为10～80 mg/L和20～120 mg/L;检出限分别为0.28和0.76 mg/L;RSD分别为1.3%、 2.5%.该方法可用于分析水溶液中季铵盐的含量.     

Analysis of organic quaternary ammonium salts by LAMMA

Summary The application of the laser microprobe mass analyser (LAMMA) to several acyclic quaternary ammonium salts with aliphatic and aromatic substituents was investigated. The LAMMA spectra share some typical features with the ones, obtained by mass spectrometric (MS) analysis using soft ionisation techniques, e. g. the intact cations are detected as well as the iminium ions, issued from their decomposition. However, as a result of the abundant fragmentation and because of the presence of additional characteristic peaks, LAMMA spectra become largely comparable to the ones, recorded on a conventional MS with electron impact-ionisation and sample introduction by direct probe, though it is well known that the latter method induces thermal degradation of these salts and consequently only allows for the detection of the corresponding decomposition products.

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Analyse organischer quarternärer Ammoniumsalze mittels LAMMA

Zusammenfassung Die Anwendung des Laser-Mikrosonden-Massen-Analysators (LAMMA) zur Charakterisierung verschiedener acyklischer quarternärer Ammonium-salze mit aliphatischen und aromatischen Substituenten wurde untersucht. Die LAMMA-Spektren zeigen charakteristische Merkmale jener Spektren, die durch weiche Ionisierungstechniken in der Massenspektrometrie erhalten werden: z. B. werden intakte Kationen sowie Imin-Ionen detektiert. Als Folge der weitgehenden Fragmentierung und wegen zahlreicher zusätzlicher Peaks sind LAMMA-Spektren jenen Spektren sehr ähnlich, die durch Elektronenstoß-Ionisation und Direkteinführung der Probe erzeugt werden. Allerdings ist bekannt, daß die letztere Methode einen starken Abbau von Salzen bewirkt und daher nur den Nachweis von Zerfallsprodukten zuläßt.

     

The synthesis of quaternary ammonium salts from ammonium salts and dialkyl carbonate

Quaternary ammonium salts were synthesized from ammonium salts and dialkyl carbonates over an ionic liquid catalyst 1-ethyl-3-methylimidazolium bromide.     

Microwave synthesis of quaternary ammonium salts

The microwave synthesis of several quaternary ammonium salts is described. The synthesis provides comparable or better yields than published methods with reduced reaction times and in the absence of solvent.     

Utility of quercetin for determination of some tertiary amine and quaternary ammonium salts

A simple and sensitive spectrophotometric method for the assay of eight drugs containing quaternary ammonium or tertiary amine moieties is described. The method is based on the interaction of these drugs with quercetin after its oxidation with N-bromosuccinimide (as counter ion) to give highly colored ion-pairing complexes extractable with organic solvents. The absorbances of the colored complexes are measured in the range of 528-560 nm. Beer's law is obeyed for the studied drugs in the range 5-30 mug ml(-1). The method is successfully applied to the analysis of the studied drugs in commercial dosage forms.     

Stepwise determination of quaternary ammonium salts and aromatic amines in pharmaceuticals by ion association titration.

A stepwise titrimetric method has been developed for the simultaneous determination of pharmaceutical quaternary ammonium salts (R4N+) and aromatic amines (R3N). The method is based on the solvent extraction of R4N+ and R3NH+ with an ion association reagent. Sodium tetrakis(4-fluorophenyl)borate and sodium tetraphenylborate were used as titrants and potassium tetrabromophenolphthalein ethyl ester (TBPE) was used as an indicator. The ion associate which formed between R4N+ ion and TBPE made a blue color in 1,2-dichloroethane, while the ion associate formed between R3NH+ and TBPE showed a red-violet one. Sample solutions containing quaternary ammonium and/or amine compounds were titrated with sodium tetrakis(4-fluorophenyl)borate or sodium tetraphenylborate. When one drop of excess titrant was added, the color of the organic phase turned from blue or red-violet to yellow at the equivalence point. On the other hand, in the mixture of R4N+ and R3N, the color changed from blue to red-violet at the first equivalence point, and then its color turned to yellow at the second equivalence point. The quaternary ammonium compound and aromatic amine in pharmaceuticals could be simultaneously and successfully determined by the proposed titration method.     

Analytical application of high-molecular quaternary ammonium salts

Summary The anion-exchange extraction of a great number of mineral, organic and metal complex anions by solutions of quaternary ammonium-salts (QAS) in different solvents, including intermediate exchange with acidic dye anions, has been investigated. Extraction-photometric methods and ion-selective electrodes for the determination of organic and metal complex anions have been developed. Simple methods for synthesis and purification of QAS are described and their self-association has been investigated by electroconductivity and interphase distribution.

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Analytische Anwendung von hochmolekularen quaternären Ammoniumsalzen

     

Spectra of quaternary ammonium salts taken by fission-fragment and laser-induced desorption

Mass spectra of quaternary ammonium salts obtained by fission-fragment induced desorption and laser induced desorption are reported and compared with those obtained by static secondary ion mass spectrometry as well as by field desorption and by field desorption/collisional activation. The principal fragmentation pathways are the same. Certain differences are discussed.     

Mixed micellar properties of cationic trimeric-type quaternary ammonium salts and anionic sodium n-octyl sulfate surfactants

The properties of quaternary ammonium salt-type cationic trimeric surfactants (m-2-m-2-m, m represents the carbon atom number in alkyl chain lengths of 8, 10, and 12) and oppositely charged anionic monomeric surfactant, sodium n-octyl sulfate (SOS), were characterized by employing several techniques such as static surface tension, fluorescence spectroscopy, and dynamic light-scattering measurements. The critical micelle concentrations (cmc) of m-2-m-2-m were much lower than those of the corresponding dimeric and monomeric surfactants, and decreased with increasing chain length. The addition of SOS to m-2-m-2-m solutions resulted in a further decrease of the cmc. The mixed surfactants showed higher efficiencies in lowering the surface tension than the individual surfactants. The fluorescence measurements suggested the formation of mixed micelles with a hydrophobic environment in the solutions even at lower concentrations. The dynamic light-scattering study indicated the presence of two different kinds of aggregates with different hydrodynamic diameters. The larger one was attributed to the mixed micelle of m-2-m-2-m and SOS. These results indicated a decline of the electrostatic repulsion between cationic head groups through the incorporation of anionic surfactant into the mixed surfactants.     

The adsorption of quaternary ammonium salts at a mercury solution interface: Part II. Non-symmetrical quaternary ammonium salts

The adsorption of triethyl alkyl (and allyl) ammonium bromides on a mercury electrode has been investigated. The isotherms and values of the free energy of adsorption yield information on the mode of adsorption of the cations. The formation of partial bimolecular films on the surface of mercury by the cations studied has been described and a simple explanation put forward concerning the mechanism of destruction of these films.