摘要:

Cypermethrin and alphamethrin ([1R, cis, αS]- and [1S, cis, αR]-cypermethrin) are pyrethroid insecticides used in agriculture, forestry, and public health hygiene. After forestry applications of cypermethrin against bark beetles diastereo- and enantioselective analyses of pyrethroid residues are performed by gas chromatography (GC) with electron capture (ECD) and mass spectrometric (MS) detection, or by achiral and chiral high performance liquid chromatography (HPLC). The major soil metabolites of cypermethrin, i.e. 2,2-dimethyl-3-(1,1-dichlorovinyl)-cyclopropylic acid and 3-phenoxybenzoic acid, are analyzed as methyl esters by GC-MS with electron-impact (EI) ionization. On spruce bark cypermethrin persists several months as surface films of 1 μg/cm2.In soil it is detected as long as seven months after treatment at levels of 0.15–0.7 μg/g. Sunlight-induced cis, trans isomerization on bark and leaves results in an excess of trans-cypermethrin isomers. In soil cis-cypermethrin isomers are more persistent than their corresponding trans-isomers. Enantioselective HPLC demonstrates chiral discrimination of a pair of trans-cypermethrin enantiomers. Analysis of soil metabolites is less meaningful since traces of the investigated products are formed from pyrethroid residues during the extraction and derivatization procedures.

ISSN:0306-7319    

DOI:10.1080/03067319208027571

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Nitrodibenzopyranones have recently been shown to be present in ambient air and to contribute substantially to the mutagenicity of ambient air particulate extracts. To allow their isomer-specific analysis in ambient samples, nitro-isomers (2-, 3- and 4-nitrodibenzopyranone and a fourth isomer tentatively identified as 8-nitrodibenzopyranone) and the parent dibenzopyranone were characterized by their1H-NMR spectra, mass spectra and their gas chromatographic retention indices on DB-5, DB-1701 and SB-smectic stationary phases. 2-, 3 and 4-Nitrodibenzopyranone were well resolved on DB-5 and DB-1701 columns. Since only 2- and 4-nitrodibenzopyranone have been identified in atmospheric samples, 3-nitrodibenzopyranone may prove suitable as an internal standard for quantitative analysis.

ISSN:0306-7319    

DOI:10.1080/03067319208027572

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The extraction of polycyclic aromatic hydrocarbons (PAH) from sediments and from an urban dust standard reference material (SRM 1649) was compared using two methods; ultrasonication and Soxhlet extraction. Sample weights ranging from 0.5 g to 5 g were extracted using ultrasonication. The yield of organic material from sediment samples using ultrasonication with two solvents was 2.53 ± 0.10% while the Soxhlet method yielded 2.41 ± 0.14% of the initial sample weight. Sequential ultrasonic extraction with two solvents was much more rapid (45 minutes) than Soxhlet extraction (two days) and resulted in equal extraction efficiency. The levels of PAH extracted by ultrasonication from the urban dust standard reference material varied by no more than 15% from the certified values.

ISSN:0306-7319    

DOI:10.1080/03067319208027573

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The determination of chlorophenoxyacetic acid herbicide residues was done with GC-ECD as pentafluorobenzyl derivatives. The herbicides were separated on a 3% Silar 10 CP column, which permits better resolution from interfering organic acids of environmental origin. The fortification study provides an 84–91% recovery for the water and sediment samples. The detection limits were established as 0.1 μg/1 for the water and 1.0–1.5 ng/g for the sediment samples. The use of a 3%Silar 10 CP packed column in the monitoring study as compared with a 1.5% OV-17 + 1.95% QF-1 one, shows the very small amount of contamination of the samples with these herbicide classes.

ISSN:0306-7319    

DOI:10.1080/03067319208027574

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Environmental Health. The Impact Of Pollutants.Edited by J. Rose.455 pages. Environmental Topics, Vol. I. New York, Gordon and Breach, New York, London (1990) US$ 90.00.

ISSN:0306-7319    

DOI:10.1080/03067319208027575

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

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

ISSN:0306-7319    

DOI:10.1080/03067319208027570

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor