Spectrophotometric determination of phenothiazines, tetracyclines and chloramphenicol with sodium cobaltinitrite

A spectrophotometric method for determining some phenothiazines, some tetracyclines and chloramphenicol is described. Chlorpromazine hydrochloride, promazine hydrochloride, promethazine hydrochloride, perphenazine and fluphenazine hydrochloride are reacted with sodium cobaltinitrite in phosphoric acid. The red colour developed is measured at 530, 513, 515, 530 and 500 nm, respectively. Tetracycline hydrochloride, oxytetracycline hydrochloride, chlortetracycline hydrochloride, doxycycline hyclate and demeclocycline hydrochloride are reacted with the reagent in aqueous acetic acid. The yellow colour produced is measured at 256, 294, 262, 243 and 246 nm, respectively. Chloramphenicol is determined similarly to the tetracyclines after hydrolysis with 40% sodium hydroxide solution and the colour is measured at 240 nm. The proposed method has been successfully applied to the determination of these drugs in various pharmaceutical preparations.     

Analytical application of atomic emission and atomic absorption spectrometry for the determination of imidazoline derivatives based on formation of ion-associates with sodium cobaltinitrite and potassium ferricyanide

Ion-association complexes of Naphazoline HCl (I), Tolazoline HCl (II) and Xylometazoline HCl (III) with [Co(NO₂)₆]^3– and [Fe(CN)₆]^3– were precipitated and the excess of the unreacted iron or cobalt comples was determined. A new method using atomic emission and atomic absorption spectrometry for the determination of the above drags in pure solutions and in pharmaceutical preparations is given. The drugs have been determined in the ranges 0.98–14.76, 0.78–11.80 and 1.12–16.80 g/ml solutions of I, II and III. respectively, using [Co(NO₂)₆]^3–], with mean relative standard deviations of 0.4–1.5% and 1.92%–19.68, 1.52–5.68 and 2.24–22.4 g/ml solutions of I, II and III, respectively using [Fe(CN)₆]^3– with mean relative standard deviations of 0.6–1.6%. The recovery values of 98.12–101.26% indicate high precision and accuracy.     

Thermogravimetric determination of magnesium,potassium and lead by precipitation with dilituric acid

The thermolysis curves of magnesium, potassium, and lead diliturate have established that either the hydrated or anhydrous forms of these precipitates are stable enough for their gravimetric use to be possible. Magnesium and lead were determined by precipitation with dilituric acid while potassium was precipitated with trimethylamine diliturate.     

Estimation of the alkaline earths metals by sequential titration with sodium tetraphenylborate

Summary Alkaline earths metals were titrated potentiometrically in the presence of polyethylene glycol with sodium tetraphenylborate. The sensor was a coated-graphite rod. The method can be used for the sequential estimation of barium, strontium, and calcium. The solubility of the precipitated species decreases with increasing atomic weight of the metals.

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Bestimmung von Erdalkalimetallen durch sequentielle Titration mit Natriumtetraphenylborat

Zusammenfassung Die Erdalkalimetalle wurden potentiometrisch in Gegenwart von Polyethylenglykol mit Natriumtetraphenylborat titriert. Als Sensor diente eine überzogene Graphitstabelektrode. Sequentiell können Barium, Strontium und Calcium bestimmt werden. Die Löslichkeit der Niederschläge nimmt mit ansteigendem Atomgewicht ab.

     

Cryolite precipitation by the Reaction of aluminium salt with sodium fluoride in aqueous solution

When aqueous solution of aluminium salt involving nitrate, chloride or sulfate was added into sodium fluoride solution, an immediate reaction occured to form cryolite-like precipitate. Examination into the resultant solution and analysis for the precipitate were carried out, leading to the fact that fluorine ion can substitute for bound water molecules around central Al⁺⁺⁺ ion, but hardly for bound hydroxide and sulfate ion which should go or be “frozen”, as it is, into cryolite-like precipitate. These ligand substitution reaction seems to contribute to identification of ion species of aluminium in aqueous solution.     

Indirect complexometric titration of sodium and potassium with EDTA

Summary Sodium is precipitated as sodium zinc uranyl acetate, filtered and dissolved in water, and zinc is titrated with EDTA using eriochrome black T as indicator. Potassium is precipitated as potassium sodium cobaltinitrite and dissolved in hot water containing little hydrochloric acid. The blue colored solution produced by cobalt in solution, with ammonium thiocyanate and acetone was titrated with EDTA until colorless. The results are good.The author is grateful to Prof. Philip W. West, Boyd Professor of Chemistry, Louisiana State University, for kindly providing the facilities to carry out the investigation.     

The preparation of sodium and potassium borohydrides by the reduction of boron halides by sodium and potassium hydrides in the presence of aluminum triethyl

Summary It was found that sodium and potassium hydrides readily react with boron halides in hydrocarbon solvents in the presence of aluminum triethyl to form the borohydrides of sodium and potassium, respectively.     

Separation of sodium and potassium by ion-exchange on cellulose phosphate

(24)Na and (42)K can be separated by ion-exchange chromatography with 80% methanol-2M hydrochloric acid on an 80 x 6mm column of cellulose phosphate. On cellulose phosphate paper the R(f) values are 0.63 for Na and 0.40 for K.     

Doping mechanism of C60 fullerene by sodium and potassium

ESR spectra of localized states of KC₆₀ and K₂C₆₀ and conducting electrons of K₃C₆₀ were recorded in the process of doping C₆₀ by potassium. The ESR spectra of K _x C₆₀ (x < 3) and Na _x C₆₀ correspond to the semiconductive state of the samples.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2190–2195, November, 1995.This work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-4101). The work was performed under terms of the interindustry program Fullerenes and Atomic Clusters.     

Hydration phenomena of sodium and potassium hydroxides by water molecules

The hydrated structures, dissociation energies, thermodynamic quantities, infrared spectra, and electronic properties of alkali-metal hydroxides (MOH, M = Na and K) hydrated by up to six water molecules [MOH(H(2)O)(n=1-6)], are investigated by using the density functional theory and M?ller-Plesset second-order perturbation theory. Further accurate analysis based on the coupled cluster theory with singles, doubles, and perturbative triples excitations is more consistent with the MP2 results. NaOH shows a peculiar trend in dissociation: it begins to form a partially dissociated structure for n = 3, and it dissociates for n = 4 and 6, whereas it is undissociated for n = 5. However, for n = 5, the dissociated structure is nearly isoenergetic to the undissociated structure. For KOH, it begins to show partial dissociation for n = 5, and complete dissociation for n = 6.     

Reactions of 1-halocycloheptenes with potassium t-Butoxide and with sodium pyrrolidide

Reactions of 1-halocycloheptenes with KO-t-Bu in DMSO and THF were studied. The principal products obtained could be accounted for on the basis of two competing dehydrohalogenation mechanisms. These are: dehydrohalogenation across the C₁-C₂ bond to give cycloheptyne; and dehydrohalogenation across the C₁-C₇ bond to give 1,2-cycloheptadiene. One or both of these intermediates react with KO-t-Bu to give 1-t-butoxycycloheptene in poor yield. The principal product from the three 1-halocycloheptenes in both solvents is tricyclo[7.5.0.0²8]tetradeca-2,14-diene (4), the dimer of 1,2-cycloheptadiene. Also formed are 5, the 2(8), 14-diene isomer of 4, presumably by cycloaddition of 1,2-cycloheptadiene and cycloheptyne, and 6, the 2,13-diene isomer of 4, by rearrangement of 4 effected by KO-t-Bu.Also studied were rections of 1 chloro- and 1-iodocycloheptene with sodium pyrrolidide (Na- NC₄H₈) in THF. These reactions give 1-(1-pyrrolidino)cycloheptene in fair yield together with smaller amounts of the 14-carbon hydrocarbons. Reactions of 1-chlorocycloheptene-1-¹⁴C and 4-chloro- and 4-iodobicyclo[5.1.0]oct-3-ene leading to (1-pyrrolidino)cycloheptenes were found to occur via both the corresponding cycloheptyne and 1,2-cycloheptadiene.     

The assay of sodium citrate and sodium potassium tartrate by cation exchange and non-aqueous titrimetry

Sodium citrate and sodium potassium tartrate are assayed by passing aqueous solutions of the salts through cation exchange resin columns, concentrating the effluents from the columns, and then titrating the effluents with standard sodium hydroxide solution. Sodium citrate is assayed by titrating a solution of the salt in glacial acetic acid with standard acetous perchloric acid, the end-point being detected potentiometrically; sodium potassium tartrate is assayed by stirring the salt in excess standard acetous perchloric acid, and then backtitrating the excess acetous perchloric acid with standard acetous potassium acetate, the end-point being detected potentiometrically.     

Reaction of 2,2,3,3-tetracyanocyclopropyl ketones with sodium and potassium hydroxides

Reaction of 2,2,3,3-tetracyanocyclopropyl ketones with water solution of sodium hydroxide after neutralization with sulfuric acid leads to the formation of 4-amino-1-hydroxy-3,6-dioxo-2,3,5,6-tetrahydro-1Hpyrrolo[3,4-c]pyridine-7-carbonitriles. Pivaloyltetracyanocyclopropane reacts in another way and is converted into sodium 6a-tert-butyl-3,4-dicyano-5-oxo-1,5,6,6a-tetrahydropyrrolo[2,3-b]pyrrol-2-olate. 1-Benzoyl-1-methylcyclopropane-2,2,3,3-tetracarbonitrile reacts with the sodium hydroxide with the retention of the threemembered ring and the formation of 11-methyl-4-phenyl-3,5,9-triazatetracyclo[5.3.1.01,7.0^4,11]undecane-2,6,8,10-tetraone.     

非线性优化迭代-紫外分光光度法同时测定苯甲酸钠和山梨酸钾

提出一种用连续波长的紫外光谱吸光度数据对两组分防腐剂（苯甲酸钠、山梨酸钾）混合物体系的定量分析方法。该方法利用连续波长信息将摩尔吸光系数和待测浓度同时作为自变量,建立非线性优化模型,对于组分浓度差较小的混合物体系经一次优化分析计算可得待测浓度;混合物中浓度差较大的体系经四次左右优化迭代,逐步降低误差得分析结果,相对误差可控制在1．52％之内。分析结果表明该法稳定、准确、简便快速、实用灵活,可对食品防腐剂进行定量测定。     

消解氨溶-火焰原子发射光谱法测定丁苯橡胶中的钾、钠

和浓硝酸消解了丁苯橡胶样品，再用氨水溶解消解产物。取适量消解产物的氨溶液，加入消电离剂Li^ 配制成试液，以工作曲线法测定。对样品处理方法、消解产物的溶解性质、线性范围、干扰及检出限进行了考察。测定结果的相对标准偏差小于3．9％，加标回收率为97．3％－103．7％。建立了快速同时测定丁苯橡胶中钾、钠的火焰原子发射光谱法。     

Effective recovery by KCl precipitation of highly diluted muscle proteins solubilized with sodium dodecyl sulfate.

A new, improved method is described, which takes advantage of the low solubility of potassium dodecyl sulfate (KDS), to concentrate sodium dodecyl sulfate-solubilized proteins from nanomolar solutions by KDS precipitation. The method was applied to proteins differing in Mr and pI. The effect of varying KCl, and the pH and/or concentration of the buffer on KDS-protein precipitation was studied. These parameters may be chosen to allow selective repartition of specific proteins in the pellet or supernatant. After precipitation, the hundred- or thousand-fold concentrated solutes are easily resuspended in small volumes of any required medium. Though initially experimented to recover muscle proteins from effluents of electroendosmotic preparative gel electrophoresis, the method proved to be of general interest as a powerful tool to recover proteins from highly diluted solutions.     

Differential elution of sodium or potassium dihydrogen- and hydrogenphosphate ions from a sephadex G-15 column with sodium or potassium chloride solution

When a mixed solution of sodium or potassium dihydrogenphosphate and disodium or dipotassium hydrogenphosphate was eluted from a Sephadex G-15 column with either a sodium or potassium chloride solution, the elution profiles of ions showed that the hydrogenphosphate ion was eluted more rapidly than the dihydrogenphosphate ion. When the sample solutions containing potassium dihydrogenphosphate and/or dipotassium hydrogenphosphate, all of which were supplemented with phosphorus-32-labelled potassium dihydrogenphosphate, were eluted with sodium chloride solution, the elution profiles of radioactivity showed that the dihydrogenphosphate ion changed to hydrogenphosphate ion and vice versa, depending on the pH values of the sample solution and the availability of the cation of the eluent during elution for the phosphate ion to pair with.     

Separation of mixtures of sodium and potassium ions by charge mosaic dialysis

Charge mosaic membranes contain a mixture of anionic and cationic elements separated by thin neutral regions. In order to maintain eloctroneutrality, the overall flux of salts from electrolytic solutions through such membranes must occur with equal transport of cationic and anionic charge. The flux rate depends on the resistivities of the exchange elements and the solution composition. It is shown that Na⁺ and K⁺ can have vastly different relative transport rates depending on the selection of the membrane formulation and the receiver composition. The effect is attributed to ionic polarization of the membrane.