摘要:

Indirect determination of trace concentrations of iron was studied by monitoring the decrease of the a. c. polarographic wave of 1, 10- phenan tli rol i ne (phen). Fundamental harmonic, with current measured at Φ = 90°, was utilized. The best supporting electrolyte was found to be a 0.6 H NaClO4solution of pH 4.5 with acetate buffer. The approach consists in running polarograns for the supporting electrolyte containing buffer and phen, subsequent to sample addition, and after each addition of standard, respectively. The effect of pH, buffer system, some common anions and iron(III) was investigated. The method has been applied to the determination of iron in pure samples, reference standard material, and tap water. The detection limit was 4 ng mL−1.

ISSN:0003-2719    

DOI:10.1080/00032718808059909

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Nifedipine, a calcium antagonist drug, proceduces a well-defined polarographic wave due to the four-electron, four-proton reduction of the nitro group. This peak is diffusion-controlled and shows a linear dependence on the Nitrendipine concentration. This behaviour is used for analytical purposes in determining Nitrendipine content in commercial preparations. The method is sensitive enough to be applied to single tablet, assays.

ISSN:0003-2719    

DOI:10.1080/00032718808059910

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

AsI3is demonstrated to partition from a 9 M HC1, 0.10 M KI, 0.10 H ascorbic acid solution into kerosene and dodecane membranes which do not contain complexing agents. Subsequent hydrolysis at the membrane receiver interface causes a transport of As against its concentration gradient. A 60 minute experiment with a 4 mL receiver solution and a 200 mL sample permits the preconcentration of As by a factor of 16 ± 0.5. The interferences of aluminum and phosphate on the graphite furnace atomic absorption spectro-metric determination of As are eliminated. This transport mechanism, which has not been previously reported, may allow the range of species which can be preconcentrated by transport across supported liquid membranes to be significantly extended.

ISSN:0003-2719    

DOI:10.1080/00032718808059911

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A simple spectrophotometric method for the trace determination of nitrite (NO−2) is described. Nitrite is reacted with Salbutamal sulphate in acidic medium which gives a yellow colour in alkaline medium (⩾pH 7) and can be determined in the presence of several cations and anions. Beer's law is obeyed in the range of 1.8 to 27.6 ppm of nitrite with the molar absorptivity 1.8 × 1031 × mole−1× cm−1at 4l0 nm. The proposed method can also be utilized for the determination of nitrate (NO−3) after its reduction to nitrite. The method has been applied for the determination of various samples containing traces of nitrite.

ISSN:0003-2719    

DOI:10.1080/00032718808059912

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A comparison has been made on the selectivity, accuracy and precision of spectrophotometric, conductometric and potentiometric methods for the determination of ascorbic acid in water which is based on the reduction of gold(III) ion by ascorbic acid. Gold(III) ion forms a complex with gelatin in alkaline medium which on reduction with ascorbic acid produces coloured gold sol. The sol shows an absorption maximum at 540 nm with molar absorptivity of 2.3×10−3litre mol−1cm−1and the Sandell's sensitivity of 7.6 × 10−2μgcm−2. The relative standard deviation is 0.22% and the confidence limit (20 determinations, 95%) is 2.0 ± 0.009%. To examine the extent of sensitivity of the spectrophotometric method the proposed method is compared with the sensitivities of the conductometric and potentiometric methods.

ISSN:0003-2719    

DOI:10.1080/00032718808059913

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An extraction-spectrophotometric method for the determination of trace amounts of iron based on its extraction into chloroform with 2-(4, 5-dimethyl-2-thiazolylazo)-4, 6-dimethylphenol has been developed, which allows the determination of 5–28 μg Fe (ϵ773= 1.38×1041. mol−1. cm−1). The use of second order analogue derivative spectrophotometry allows the determination of down to 0.2–5 μg, Fe. The methods are quite selective and have been applied to the determination of iron in mineral waters.

ISSN:0003-2719    

DOI:10.1080/00032718808059914

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

The reactions among 4-(2-pyridylazo)resorcinol (PAR), mercury(II) and/or cyanide ion in the presence of water soluble surfactants alone or combination were systematically investigated at about pH 9. The spectrophotometric determinations of mercury(II) and cyanide ion were investigated by using the PAR-mercury(II)-HPC complex (3:2:2 molar ratio) in the presence of N-hexadecylpyridinium chloride (HPC) alone; calibration graphs were rectilinear in the ranges of 0 – 40 μg mercury(II) and 0 –10 μg cyanide ion in a final 10 ml with the apparent molar absorptivities of 5.9 × 104for mercury(II) and 2.5 × 1041 mol−1cm−1for cyanide ion at 590 nm. The proposed method had advantages—rapidity, simplicity without solvent extraction, and sensitivity in comparison with reported solvent extraction methods. The interference of foreign ions decreased 1/2–l//4-fold compared with that in the presence of non-ionic surfactant alone.

ISSN:0003-2719    

DOI:10.1080/00032718808059915

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Assay of alkaline phosphatase using an automated flow injection manifold is described. The detector used is a spectrophotometer. The measurement is based on the rate of formation of p-nitrophenol at 405 nm, from the substrate p-nitropheny1 phosphate. The linear range, precision and accuracy of the technique for the assay of the enzyme is given. The advantages of the approach to assay of plasma enzymes are also discussed.

ISSN:0003-2719    

DOI:10.1080/00032718808059916

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0003-2719    

DOI:10.1080/00032718808059898

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor