摘要:

Standard solutions of dimethylarsinic acid in water and methanol are deposited on Whatman No. 1 and No. 114 filter papers. The arsenic content is measured by X-ray fluorescence spectrometry. The observed specific count depends on the nature of solvents, the volume of spotting solutions, the method of spotting and the type of filter papers.

ISSN:0003-2719    

DOI:10.1080/00032718208064435

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The fluorescence lifetime τ enters into the Perrin-Weber equation used to determine rotational relaxation times of proteins by the steady-state depolarization method. If is either too short or too long, the relaxation time cannot be measured with precision. With reasonable assumptions as to photometric precision, it has been possible to compute the precision of relaxation time assays for different lifetime:relaxation time ratios, thus also determining the “optimum” lifetimes for different systems. These results provide a basis for designing experiments requiring optimal conditions, and also provide insight into the amount of allowable deviation from optimal conditions. The short lifetimes of intrinsic protein fluorescence can often be used to determine the global relaxation rate of the macromolecule with acceptable precision.

ISSN:0003-2719    

DOI:10.1080/00032718208064436

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

o-Phthalaldehyde (OPA), a primary amino compound and a thiol react to produce a ternary isoindole-type fluorophore. The effect of the structure of the constituent amino compound on the chemical stability of isoindole fluorophores was investigated. The amino compounds with steric hindrance around the -NH2group such as L-tryptophan and L-Dopa exhibited a marked stabilization effect on the isoindole fluorophores. By using OPA and L-typtophan as reagents, a procedure was established for the fluorometric determination of thiols which permitted the determination of 2 nmol of L-cysteine (CySH). The possible mechanism for the instability of isoindole accelerated by increasing concentration of OPA was also discussed.

ISSN:0003-2719    

DOI:10.1080/00032718208064437

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A previously reported method for the determination of nitrite ion has been extended to include nitrate ion. Nitrate is reduced to nitrite by a cadmium column and the nitrite ion determined as diphenylnitrosamine. Cadmium interference is removed by pH adjustment and the use of KDTA.

ISSN:0003-2719    

DOI:10.1080/00032718208064438

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A field effect transistor sensitive to the phenobarbital anion is described. The response is Nernstian between 10−1mol 1−1and 10−4mol 1−1in the absence of added hydroxide, and 10−1mol 1−1to 10−3mol 1−1in the presence of added hydroxide. Selectivities over sulphate, chloride, nitrate, hydrogen phosphate have been determined and speed of response and stability are greater than the corresponding coated wire electrode.

ISSN:0003-2719    

DOI:10.1080/00032718208064439

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The use of the measurement of vapour pressure as an analytical tool has been studied. The vapour pressure (5.10−4to 10 mm Hg) of phthalates (1,2), isophthalates (1,3) and terephthalates (1,4) with molecular weight 194 to 418 have been determined by the inert gas saturation technique. The signal produced by this device allows an identification of the fractions issued of a liquid-liquid chromatographic column.

ISSN:0003-2719    

DOI:10.1080/00032718208064440

出版商:Taylor & Francis Group    

年代:1982

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:10.1080/00032718208064434

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor