Spectrophotometric determination of trace copper in water samples with thiomichlersketone

A simple and sensitive spectrophotometric method for determination of trace copper in water samples is proposed. In the presence of pH 4.6 HAc-NaAc buffer solution and surfactant polyethylene octyl phenyl ether (OP) medium, copper reacts with thiomichlersketone (TMK) to form a stable 1:4 complex. The complex Cu(II)-TMK-OP shows maximum absorbance at 500 nm with a molar absorptivity value of 5.7x10(4) l mol-1 cm-1. Beer's law is obeyed for copper concentrations in the range of 0-15 microg/25 ml. The average recovery of copper is between 95.8 and 106%. The method has been applied for determination of trace copper in different water samples with satisfactory results.     

Spectrophotometric determination of copper with cuproine

A study is devoted to the spectrophotometric determination of traces of copper with cuproine as reagent. After having determined the absorption spectrum of the complex, the authors have studied successively the partition coefficient water/ isoamyl alcohol ; the stability of the complex (colour); the influence of some factors: pH, foreign ions, temperature, the quality of isoamyl alcohol, excess reagent; and the validity of Beer's law. Two different calibration curves were determined, one based on complete extraction of the complex and the other based on an empirical method, which is very rapid. In both cases the mean square error is less than 1%.Finally, analysis methods were worked out for the determination of traces of copper in plants, animal tissues and blood, in water, in lamp-black and in steel.     

Spectrophotometric determination of copper with tiron

The reagent Tiron forms a soluble greenish-yellow complex with cupper. The sensitivity of the colour reaction is 0.24 mμ of copper/cm₂. The colour system at a pH of 6.1 to 6.9 is stable for over 24 h and shows a maximum absorption at 375 mμ. It obeys Beer's law at the latter wave length within a copper concentration of 10 to 160 p.p.m. The optimum range, however, is from 50 to 160 p.p.m. of copper, where the percent relative analysis error per 1% absolute photometric error is 2.94. JOB's method of continuous variation and the molar ratio method of YOE et al.² indicate that in solution the complex contains the metal and the reagent in a ratio of l : 2, with a dissociation constant on the order of 5.3 ? 10^-6.     

Spectrophotometric determination of copper with uramyldiacetic acid

A new method for the spectrophotometric determination of copper using uramyldiacetic acid as chromogenic reagent is proposed. The complex is formed in a wide pH range (2.5–9); but in order to avoid the potential conversion of UDA in murexide it is convenient to work at pH < 3: and has a maximum of absorption at 775 nm. Beer's law is obeyed in the interval 20–420 μg of copper(II)/ml. The Ringbom optimal range falls between 70 and 400 μg of copper(II)/ml, with a minimum photometric error of 2.8. The reaction between the metal and the ligand takes place in the ratio 1:1. The method has been applied to the determination of copper in ores with low content of the metal.     

Spectrophotometric determination of copper with hydrochloric acid

A procedure is proposed whereby copper may be determined spectrophotometrically by means of the very near infrared absorption of its complex ion with hydrochloric acid. Only stannous and ferrous ions are serious interferences and they may be oxidized with nitric acid or with ammonium persulfate to avoid such interference. The method is simple and rapid and is capable of reasonably good precision and accuracy.     

双硫腙褪色光度法测定痕量铈

研究了Ce(Ⅳ)在H2SO4介质中和溴化十六烷基吡啶存在下催化H2O2氧化双硫腙的褪色反应及其动力学条件,测定了反应级数和表观活化能,建立了测定痕量铈的新方法。双硫腙的最大吸收波长为450nm,该方法的检出限为1 9×10-9g/mLCe(Ⅳ),线性范围为0～150ng/mLCe(Ⅳ),方法可用于人发中痕量铈的测定。     

Spectrophotometric determination of copper with piperidinium piperidyl dithioformate

Summary The reagent piperidinium piperidyl dithioformate forms with copper in aqueous solution a yellowish brown complex which can be extracted with carbon tetrachloride. The copper-PPDF complex in carbon tetrachloride solution has maximum absorption at 434 nm. A spectrophotometric method for determining copper has been developed as the reagent has been shown to form a definite complex.

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Zusammenfassung Piperidinium-Piperidyl-Dithioformiat (PPDF) bildet mit Kupfer in wäßriger Lösung einen gelbbraunen Komplex, der mit Tetrachlorkohlenstoff extrahierbar ist. Dieser Extrakt zeigt maximale Absorption bei 434 nm. Eine spektrophotometrische Methode zur Kupferbestimmung ließ sich auf Grundlage dieses Verhaltens entwickeln, da das Reagens eine definierte Komplexverbindung bildet.

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Résumé Le réactif pipéridyldithioformiate de pipéridinium forme avec le cuivre en solution aqueuse un complexe brun jaunâtre que l'on peut extraire par le tétrachlorure de carbone. Le complexe cuivre-PDFP en solution dans le tétrachlorure de carbone présente un maximum d'absorption à 434 nm. On a développé une méthode spectrophométrique pour le dosage du cuivre après avoir montré que le réactif formait un complexe défini.

     

Spectrophotometric determination of trace level thorium with n-phenylbenzohydroxamic acid

A method for the determination of thorium(IV) based on thorium-PBHA complex, which is extracted into amyl alcohol, is described. The thorium is back-extracted from amyl alcohol with 0.2M hydrochloric acid and estimated spectrophotometrically with thorin. The system has a maximum absorbance at 545 nm and obeys Beer's law between 0.5 to 12.5 ppm and the molar absorption coefficients is 1.7·10 1·mol^?1·cm^?1., Various parameters for the extraction and back-extraction and the effect of diverse ions have been studied.     

碘化物-罗丹明B光度法测定水中痕量有效氯

液氯消毒自来水的最大优点是价格低廉 ,消毒效果优良 ,使用比较方便。但液氯消毒自来水会有潜在危险的有机卤代物形成[1,2 ] 。二氧化氯(ＣｌＯ2 )是一种比液氯更为有效的消杀剂 ,它在消毒过程中几乎不形成氯仿等有机氯 ,生成的总有机氯比液氯也要少得多 ,并能明显降低异味和色度[3 ,4] 。实践证明ＣｌＯ2 是理想的饮用水消毒剂之一。ＣｌＯ2 消毒自来水后 ,水中剩余ＣｌＯ2 以及可能还有的少量氯的其他氧化态物质 ,统称为有效氯 ,其量的多少直接影响自来水的质量 ,研究剩余有效氯量 (以后均以ＣｌＯ2 计 )的测定方法 ,对自来水的生产和饮水…     

A highly sensitive colour reaction for Se(IV) with the iodide-rhodamine B-PVA system Spectrophotometric determination of trace amounts of selenium in water

A highly sensitive spectrophotometric method for determination of selenium(IV) has been developed, based on Se(IV) oxidation of I(-) to I(-)(3) in a weak-acid medium, then formation of the 1:1 ion-association complex of I(-)(3) with Rhodamine B in the presence of poly(vinyl alcohol). The molar absorptivity is 1.97 x 10(5)l.mole(-1).cm(-1). Preconcentration of Se(IV) and elimination of interfering ions is achieved by an improved thiol cotton method, so the determination has very good selectivity. Se(IV) at mug/l. levels in tap water, hot-spring water and river water has been satisfactorily determined by the method.     

丙醇-硫酸铵-水体系沉淀浮选铜光度法测定头孢哌酮钠

本文建立了沉淀浮选铜光度法测定头孢哌酮钠的方法.研究表明头孢哌酮钠降解产物中的巯基使Cu(Ⅱ)还原生成的Cu(I)形成白色硫化物沉淀,该沉淀被浮选在丙醇/水两相界面之间.通过测定溶液中剩余Cu(Ⅱ)浓度的吸光度,可以测定头孢哌酮钠的含量.吸光度与头孢哌酮钠浓度之间存在良好线性关系.线性方程:A=4.683-0.0871...     

Spectrophotometric determination of trace amounts of selenium with 4,5,6-triaminopyrimidine

4,5,6-Triaminopyrimidine reacts in acidic aqueous media with selenium (IV) to give a piazselenol which has an absorption maximum at 362 nm with a molar absorptivity of 1.72 x 10(4) 1.mole(-1).cm(-1). The compound is stable but not extractable into non-polar solvents. The calibration graph is linear up to 10 ppm of selenium, with a detection limit of 0.1 ppm in the sample solutions. Of the many different ions tested only iron (III) (in the presence of chloride) and tin (II) interfere. The method has good reproducibility, with a relative standard deviation of 1.5% for pure solutions. The application of this method to analysis of water and electrolytic copper is described.     

2,4-二氯苯基荧光酮体系分光光度法测定微量铋

研究了在十六烷基三甲基溴化铵(CTMAB)存在下,铋与2,4 二氯苯基荧光酮的显色反应条件,该体系最大吸收峰位于570nm,表观摩尔吸光系数为ε=1.48×105L·mol-1·cm-1。在0～0 68μg/mL范围内符合比尔定律。本法可用于胃药和合金中微量铋的分析。     

Spectrophotometric determination of calcium with a flow injection system

The indirect spectrophotometric determination of 0.8–7.2 ppm calcium in the presence of magnesium, phosphate and sulphate by flow injection analysis (f.i.a.) is described. The method is based on the exchange reaction between the calcium and the zinc complex of ethylene glycol-bis(2-aminoethylether)tetraacetic acid (EGTA) in the presence of 4-(2-pyridylazo)resorcinol (PAR): Ca + Zn(EGTA) + 2 PAR ? Zn(PAR)₂ + Ca(EGTA). A home-made and a commercial flow injection system with a sampling rate of 80 h^?1, are compared. Results for water samples are in good agreement with those obtained by atomic absorption spectrometry.     

Spectrophotometric determination of indoles using a modification of the ehrlich colour reaction

A sensitive spectrophotometric method for the determination of indole (1 μg/ml) in aqueous solution is described. It is also applicable to certain 3-substituted indoles. The method employs p-dimethylaminobenzaldehyde in aqueous trifluoracetic acid. With indoles this reagent gives stable colours which are more intense than those obtained in the conventional Ehrlich reaction. Factors affecting fading of the indole colour are discussed.     

酸性大红褪色光度法测定痕量铜

研究了在氨 氯化铵介质中铜催化过氧化氢氧化酸性大红的褪色反应及其动力学条件,测定了反应级数和表观活化能,建立了测定痕量铜的新方法。该方法的检出限为6.1×10-3μg/mL,线性范围为0～4.0μg/25mLCu,用于测定水中痕量Cu,结果与原子吸收法的测定结果一致。