磷、砷、硅钼杂多酸-罗丹明6G荧光猝灭法连续测定磷、砷、硅的研究

本文报道了在非离子表面活性剂PVA存在下,磷、硅、砷钼杂多酸-罗丹明6G形成离子缔合物,使罗丹明6G荧光猝灭。研究了罗丹明6G-磷、砷、硅钼杂多酸体系荧光光谱,形成条件和配合物组成。试验了共存离子的干扰。应用此方法对铜合金中磷、砷、硅进行同时测定,结果满意。     

Flame Atomic Absorption Spectrometric Determination of Arsenic After Volatilization of As(III) with Chloride Ions

 The generation of volatile species of As(III) as a means to introduce arsenic into a flame atomic absorption spectrometer has been studied. The method is based on the reaction between As(III) and chloride ions in sulphuric acid medium. The reaction is performed in a discontinuous or batch mode. With this method 130 μl of a solution containing 17.5% (w/v) sodium chloride and As(III) are injected by a 500 ml.min⁻¹ N₂ carrier gas flow into 1 ml of concentrated sulphuric acid. The gaseous compounds generated are introduced into the spectrometer through the nebulizer and As is determined. Received October 3, 1998. Revision January 6, 1999.     

Determination of antimony(III) with potassium hexacyanoferrate(III)

The determination of antimony(III) with potassium hexacyanoferrate(III) in 5M hydrochloric acid medium and in the presence of 40% v/v acetic acid is described. Ferroin is used as the indicator. Antimony has been determined in tartar emetic, solder and pig lead. Arsenic(III) does not interfere.     

Determination of Arsenic(III) at a Nanogold Modified Solid Carbon Paste Electrode

A selective and sensitive electroanalytical method was developed for arsenic determination based on a nanogold (AuNP) modified solid carbon paste working electrode (SCPE) modified in two steps (i) physisorption and (ii) additional electrodeposition of nanogold particles in the presence of iodide. Copper(II) interference was solved by covering the gold layer by a self assembled mono layer (SAM) of glutathione. Using DPASV a linear response of the signal was obtained as a function of As(III) in the concentration range 0.05–20 µM (4–1498 ppb) with a limit of detection of 0.01 µM (0.9 ppb). Sample stirring and degassing were not needed. Application to the determination of arsenic(III) and (V) in underground water samples from Burkina Faso was successfully achieved.     

Effect of Some Ion Impurities on Accuracy of Fluorometric Determination of Aluminum(III) Concentration in Natural Water

The possibility of determining the aluminum(III) concentration in aqueous solutions in the form of a complex compound with lumogallion by means of fluorometry with a portable analyzer and the effect of impurities on the accuracy of determining this concentration were studied.     

Spectrophotometry Determination of Arsenic(III) and Antimony(III) by Means of Isonicotinoylhydrazones of 4-Dimethylaminobezaldehyde (4-Dbih) and 2-Hydroxynaphthaldehyde (2-Hnih)

Abstract

4-DBIH and 2-HNIH react with As(III) and Sb(III) respectively, in CH₃COOH medium to form colored complexes stable in presence of EDTA. As(III) and Sb(III) do not react with 2-HNIH and 4-DBIH respectively, and the Sb(III)-2-HNIH complex is extractable into isoamyl alcohol. These behaviours were used for the spectrophotometry determination of As (III) and Sb(III) in presence of several cations.     

Fluorometric determination of dopamine by using a terbium (III) inorganic-organic network

Microchimica Acta - A hybrid organic-inorganic optical probe was developed by using silylated precursors (including tetraethoxy silane and aminopropyltriethoxysilane), ferroferric oxide (Fe3O4) and...     

Fluorometric Determination of Iron(Iii) with O-Hydroxyhydroquinonephthalein in the Presence of Brij 58

Abstract

A highly sensitive fluorescence reaction of iron(III) with o-hydroxyhydroquinonephthalein (Qnph) in the presence of various surfactants, and its application to the fluorophotometry of trace amounts of iron(III) is described. the method is based on the fluorescence quenching reaction between Qnph and iron(III) in the presence of Brij 58 at pH 3–4. the quenching calibration graph was linear over the range 0 – 300 ng per ml iron(III) by using fluorescence reaction at Em 525 nm with Ex 470 nm, and the iron(III) detection limit was 5 ng/ml. the proposed method is simple, rapid and does not involve heating or solvent extraction.     

Rapid Fluorometric Determination of Trace Indium(III) in Microemulsion Medium after Preconcentration and Separation by Sulphydryl Dextrane Gel

A new highly sensitive, stable, and accurate fluorometric method for the determination of indium(III) has been established in cetyltrimethylammonium bromide(CTMAB) microemulsion media. The excellent color-forming reagent 2,6,7-trihydroxy-9-(3,5-dibromo-4-hydroxyphenyl) fluorone (DBH-PF) reacts with indium(III) to form a purple complex with a 3 : 1 (ligand to metal) ratio in HAc-NaAc buffer solution at pH 4.94. The emission peak occurs at 556 nm with excitation at 525 nm. Indium(III) can be determined in the linear range of 0.005–0.30 μg mL⁻¹ with a detection limit of 0.0029 μg mL⁻¹. Foreign ions are eliminated by preconcentration and separation with sulfhydryl dextranegel (SDG). The proposed method has been satisfactorily examined for the determination of indium(III) in ore and sludge samples. The relative standard deviations are in all instances less than 3.0%, and the recoveries are between 94.7, and 99.5%. __________ From Zhurnal Analiticheskoi Khimii, Vol. 60, No. 9, 2005, pp. 979–984. Original English Text Copyright ? 2005 by Wei Qin, Du Bin, Zhang Hui, Li Yan, Li Zaijun. The text was submitted by the authors in English.     

槲皮素荧光光度测定法的研究

本详细研究了表面活性剂十二烷基磺酸钠存在下，槲皮素与锆形成三元荧光光胶束配的条件，并建立了测定槲皮素的荧光光度法。在０．９ｍｏｌ／Ｌ盐酸介质中，槲皮素与锆（Ⅳ），ＳＬＳ形成１：４：４的黄绿色荧光配合物，激发波长４３２。１ｎｍ，发射波长５０１。３ｎｍ，线性范围为０．３０×１０－６－１．１１×１０－５ｍｏｌ／Ｌ，检测限为３．７９×１０－７ｍｏｌ／ Ｌ。所拟方法用于芦丁酸水解产物的测定及槐花中回收率的     

Electrochemical Preconcentration of Arsenic(III) in Its Determination by Stripping Voltammetry at Graphite Electrodes Modified with Gold and Copper

The effect of some factors (potential and time of electrolysis, nature and concentration of supporting electrolyte) on the electrochemical preconcentration of arsenic at graphite electrodes modified with copper and gold adatoms was studied. The data obtained were used for the determination of 10^–7to 10^–6M arsenic(III) by stripping voltammetry. The detection limits for arsenic using graphite electrodes modified with copper and gold were 6.3 × 10^–7and 2.3 × 10^–7M, respectively.     

Fluorometric Determination of Cellulase

Abstract

A fluorometric procedure is described for the determination of the enzyme cellulase. The method is based upon the hydrolysis of the nonfluorescent substrate, resorufin acetate, by the enzyme to give the highly fluorescent resorufin (λ_ex = 540 mμ;, λ_em = 580 mμ). By this procedure from 0.00010 to 0.060 units per ml. of cellulase can be determined with an accuracy and deviation of about 1.5%. Evidence is offered to demonstrate cellulase, and not esterase, activity.     

Manganese(III)–Arsenic(III) Reaction Catalyzed by Some Antidotic Oxime Iodides

Manganese(III)–arsenic(III) reaction in the presence of sulfuric acid is proposed in this work as an indicator reaction for the kinetic determination of some antidotic oxime iodides. As 2-hydroxyiminomethyl-1-benzyl-3-methylimidazolium iodide, 2-hydroxyiminomethyl-3-benzyl-1-[3-(2-hydroxyiminomethyl-3-benzyl-1-imidazolio)-2-oxapropyl]-imidazolium diiodide, and 2-[(hydroxyimino)methyl]-1-methylpyridinium iodide catalyze the proposed reaction, a kinetic method for their determination in the range from 1.0 × 10⁻⁸to 8.0 × 10⁻⁸mol dm⁻³was developed. The effect of some other antidotic oximes on the accuracy of these determinations was investigated.     

Determination of antimony(III) by titration with chromium(VI)

Summary There is no need for a catalyst in the potentiometric or spectrophotometric titration of antimony(III) with chromium(VI). The failure of titrations using indicators is due to slowness of the oxidized indicator-Sb(III) reaction; the indicator reaction can be catalysed by iodine. The spectrophotometric titration yields accurate results, and shows that the Sb(III)-Cr(VI) reaction is rapid. Slowness in the potentiometric titration is due to unfavourable electrode kinetics.

---

Titration von Antimon(III) mit Chrom(VI)

Zusammenfassung Bei der potentiometrischen oder spektrophotometrischen Titration von Sb(III) mit Cr(VI) bedarf es keines Katalysators. Der Fehler bei Titrationen unter Verwendung eines Indikators hat seine Ursache in der langsam verlaufenden Reaktion zwischen dem oxydierten Indikator und Sb(III); die Indikator-Reaktion kann mit Jod katalysiert werden. Die spektrophotometrische Titration gibt genaue Resultate und zeigt, daß die Sb(III)-Cr(VI)-Reaktion rasch abläuft. Die Langsamkeit der potentiometrischen Titration ist durch die ungünstige Kinetik der Elektrode verursacht.

     

1Study on New Spectrophotometric Determination of Arsenic (V) with Chlorpromazine

IntroductionChlorpromazineasanewchromogenicreagenthasbeenemployedforthedeterminationofvanadium(V)inthislaboratoryi.ItwasfoundthatthisreagentalsogaveasensitivereactionwithheteropolyacidofAs,P,Ge,andStinstronglyacidicmedium.Inthispaper,anewmethodforspectrophotometricdeterminationofarsenic(V)withchlorpromazineisreported.Theoptimumconditionsforcolordevelopmentofthecomplexandtheeffectsofforeignionswerestudied.Itispossibletoestablishasensitiveandselectivespectrophotometricmethodforthedeterminatio…     

Fluoriketkic Determination of Au(III) with Eipyridyiglyoxai Diphiikylhybrazone

Abstract

A new spectrofluorimetric method for the determination of gold using bipyridylglyoxal diphenylhydrazone as reagent, has been developped. The interferences of foreign ions are also determined.     

1-(2-吡啶偶氮)-2-萘酚-镱二元络合物近红外发光法测定镱

基于金属指示剂 1 (2 吡啶偶氮 ) 2 萘酚 (PAN)对稀土离子Yb3+ 的近红外发光的敏化作用 ,建立了Yb3+ 的定量分析方法。方法的线性范围为 1 .0× 1 0 - 6 ～ 8.0× 1 0 - 6 mol L,检测下限为 1 .0× 1 0 - 6 mol L ,相对标准偏差为 3 .2 %。该方法适用于在混合稀土样品中选择性地测定Yb3+ 的含量。     

催化动力学测定痕量砷(Ⅴ)的研究

在硫酸介质中,痕量砷(Ⅴ)能灵敏地催化过氧化氢和高碘酸钾氧化二甲苯蓝FF褪色的指示反应,研究了该催化反应的最佳条件与动力学参数,建立了一种新的测定痕量砷(Ⅴ)的方法.该法的线性范围0～4.0 μg/L As(Ⅴ),检出限为9.8×10-8 g/L,用于食品中砷(Ⅴ)的测定,结果满意.