摘要:

This paper describes a selective method for the assay of benzo(a)pyrene (BaP) in 24 hour particulate samples. Benzo(a)pyrene is partially separated from the other polynuclear aromatic hydrocarbons via gas chromatography and then is completely resolved optically from traditionally difficult to resolve compounds (benzo(e)pyrene, perylene, benzo(k)fluoranthene) by means of a gas phase fluorescent detector. Ambient air concentrations as low as 20 picograms per cubic meter of air can be assayed with this gas chromatographic - gas phase fluorescent detection system.

ISSN:0003-2719    

DOI:10.1080/00032717508058236

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Organic mercury compounds in lake sediments were separated into dialkyl- and monoalkylmercury fractions by steam distillation and subsequently quantified by flameless atomic absorption. The method recovered nearly all CH3HgCH3and CH3HgCl added to diverse sediments. Parameters influencing the efficacy of the procedure, i.e., Hg concentration, sample size and distillation time, were evaluated.

ISSN:0003-2719    

DOI:10.1080/00032717508058237

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

A simple and precise colorimetric method of determining thiosulfate and tetrathionate is described. It involves alkaline cyanolysis of thiosulfate S in the presence of Cu2+or alkaline cyanolysis of tetrathionate S in the absence of Cu2+and colorimetric determination of the thiocyanate formed as ferric thiocyanate complex. The method is rapid, sensitive, and accurate, and it permits determination of microgram quantities of thiosulfate or tetrathionate or both. The stability of the color formed is discussed, and the ratio of tetrathionate recovered in the presence and absence of Cu2+is presented.

ISSN:0003-2719    

DOI:10.1080/00032717508058238

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The method involves the conversion of the P and As into the yellow 12-molybdo-phosphate or - arsenate complex, respectively, extraction into butyl acetate (in the case of As - with the preliminary addition of ethanol), the decomposition of the heteropoly-compounds with aqueous NH3and the back extraction of the liberated Mo into aqueous solution, for flameless AA determination. 10 pg P and 25 pg As in 0.4 ml samples of ultrapure water were determined with percentage errors below ±30%.

ISSN:0003-2719    

DOI:10.1080/00032717508058239

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

An improved colorimetric method for the determination of boron was developed by investigating the effects of temperature, time, reagent concentration and composition of the reaction mixture on colour development with azomethine-H. Among 15 ions studied, only fluoride, aluminum, ferric and cupric ions interfered with colour development at below 10,000 ppm in sample aliquot. Tolerable concentrations for these ions were 5,000 ppm fluoride, 3,000 ppm aluminum, 2,500 ppm cupric and 200 ppm ferric ion. The method accounted for known additions of boron to nomal hydrochloric acid extract of plant material, to hot water extract of soil and to effluent. Boron determinations in these samples and sewage sludge extract were in close agreement with results obtained by the carmine method. The proposed azomethine-H method was found advantageous since use of concentrated sulphuric acid is avoided and smaller variations in results and superior precision are obtained.

ISSN:0003-2719    

DOI:10.1080/00032717508058240

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Atomic absorption spectroscopy (AAS) has been demonstrated to be a metal-specific detector for chromium organometallic compounds separated by high pressure liquid chromatography (HPLC). Column effluent from the HPLC instrument was fed directly to the aspirator of the atomic absorption instrument set to record absorption due to chromium. Well defined peaks were obtained. In addition to being specific for a given metal, the method is free of some of the constrictions placed upon conventional ultraviolet absorption and refractive index detectors commonly used with HPLC. For example, solvents which absorb strongly in the ultraviolet may be employed and there is no need to use expensive spectroquality solvents. The method promises to be particularly useful for the analysis of specific organometallic compounds found in liquefied coal and shale oil.

ISSN:0003-2719    

DOI:10.1080/00032717508058241

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The complexations of a new ligand,o-(2-thiazolylazo)-4-ethylphenol(TAEP) with Ca(II), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hq(II) and Pb(II) have been studied by potentiometric titrations, at 25.0 ± 0.2°C and an ionic strength of 0.1 in 30% v/v dioxane-water mixture. The dissociation constant and spectral data of TAEP and formation constants of the complexes containing various molar ratios of metal ion to ligand, are reported. It is observed that Ca(II) forms only an ML complex in any molar ratios, whereas other metal ions react in two steps forming ML and ML2complexes in a 1:3 molar ratio. In the case of 1:1 and 1:2 molar ratios, Mn(II), Co(II), Cd(II) and Hg(II) seemed to form bi- or poly-nuclear complexes because of slightly different formation curves from those of 1:3 molar ratio. The sequence of the first successive formation constant is Cu > Hg > Ni > Pb > Co > Zn > Cd > Mn > Ca, showing Mellor-Maley's order. Further correlation is shown between the formation constants and the second ionization potentials of the metals.

ISSN:0003-2719    

DOI:10.1080/00032717508058242

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Experimental conditions of acidity and pH have been studied for the determination of several oxidants and reductants on tetrachlorohydroquinone (TCHQ) and tetrachloroquinone (TCQ) columns.

ISSN:0003-2719    

DOI:10.1080/00032717508058243

出版商:Taylor & Francis Group    

年代:1975

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:10.1080/00032717508058235

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor