摘要:

The use of a KI-coated annular denuder for eliminating NO2interference during sampling of airborne particulate matter on filter media is proposed. The performances of this novel diffusion sampler were evaluated in a series of practical tests concerning optimization of the sorption efficiency of NO2. Results pointed out that a properly sized annular denuder under 1 m long could be able to remove HO2before collecting aerosols at laminar airflows as high as 15 1 min−1.

ISSN:0003-2719    

DOI:10.1080/00032718408077170

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A rapid and sensitive method of the assay of polyacrylamide in drilling fluids at the drill site for oil exploration is described. Base hydrolysis and a gas sensing electrode are utilized. Polyacrylamide was determined from 0.031 to 4.81 w/w% with an average error of 1.79% and an average standard deviation of 0.17.

ISSN:0003-2719    

DOI:10.1080/00032718408077171

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Recent advances in column and instrument technology have made the development of d new generation of high-resolution microcolumn liquid chromatography possible. In addition to offering reduced solvent consumption, this chromatographic technique also yields higher mass sensitivities than those in conventional systems. In this study, the applicability of this technique to the analysis of polycyclic aromatic hydrocarbons (PAH) is investigated. PAH in the extract from diesel particulate matter were analyzed to demonstrate the utility of this approach combined with the computer-assisted retention prediction. The technique proposed in this study makes very clean and high cost-performance environmental analysis possible.

ISSN:0003-2719    

DOI:10.1080/00032718408077172

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A method is described for the residue analysis of carbaryl in polluted water samples. The technique is based on catalytic hydrolysis of the carbaryl on anion exchangers followed by fluorescence detection of the α-naphthol or the OPA derivative of the methyl amine. A low cost 200 mesh Amberlite strong anion exchanger can be used for this purpose when coupled to the OPA reaction detector. Combining this approach with on-line preconcentration and clean-up on an 3P-18 loaded precolumn can provide a powerful tool for automated residue analysis of carbaryl (and other N-methyl carbamates) in polluted water sources. Recoveries in the order of 100% are reported. The reproducibility of the technique is better than 2% rel. st. dev. Detection limits are 0.4–2 ng per injection for carbaryl depending on the system and linearity of response is more than two orders of magnitude with r = 0.9998. The selectivity and sensitivity of this method permits residue analysis at the sub ppb concentration level in heavily polluted water samples. Data on hydrolysis yields and band broadening as a function of residence time and temperature in the reactor are given.

ISSN:0003-2719    

DOI:10.1080/00032718408077173

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The chromatographic potential of very short fused-silica column (30 mm length) packed with 3-μm particles has been investigated. The results indicate that this kind of micro-column has high applicability for a rapid identification of several samples. This technique also meets the recent demands in HPLC, as low solvent consumption and faster analysis time.

ISSN:0003-2719    

DOI:10.1080/00032718408077174

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Ortho-, meta- and para-isomers of various derivatives of phenols and aromatic acids have been separated on a cross-linked poly (ethyleneimine) coated silica gel micro-column liquid chromatography with very dilute carbonate or phosphate eluents.

ISSN:0003-2719    

DOI:10.1080/00032718408077175

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Polarographic studies of molybdosilicic acid in a citrate buffer solution have been made. Phase-selective alternating current of 1st harmonic (AC 1T) has been the technique of choice, although differential pulse (DP) and fast direct current (DCT) have also been tried. A specific peak of each form of MSA, α and β has been observed and studied as a function of pH with AC 1T. The kinetic study in the range of pH in which both forms of the acid are produced could therefore be possible. The time of formation of each species has been estimate at various pH values, as well as the influence of the molybdate concentration in the polarograms of α-MSA. The peaks of molybdate reduction as a function of pH have also been characterized.

ISSN:0003-2719    

DOI:10.1080/00032718408077176

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The determination of tellurium at nanogram levels using electrothermal atomic absorption spectroscopy is examined. Severe interferences are observed in the presence of many elements but can be overcome by the use of a sequential extraction scheme.

ISSN:0003-2719    

DOI:10.1080/00032718408077177

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The spectrophotometric study of reddish cyclohexane-1, 3-dione bis (4-methylthiosemicarbazone)-Zn(II) was made in dimethylformamide-water solution (λmax= 475 nm, ∑ = 3.3×1041.mole−1. cm−1. Sandell sensitivity = 2×10−2μg Zn(II).cm−2, stoichiometry 1:1, and apparent stability constant 6.1×104). A new method for the spectrophotometric determination of Zn(II) is proposed for concentrations between 0.1 and 2.5 ppm. The relative error (95% confidence level) is 0.7% for 1.0 pprn of Zn(II).

ISSN:0003-2719    

DOI:10.1080/00032718408077178

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

8-Amino-1-naphthol-5-sulfonic acid is proposed as a self-coupling diazotizing reagent for the determination of nitrite.

ISSN:0003-2719    

DOI:10.1080/00032718408077179

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor