AbstractThe screening procedure for the determination of pesticide residues in tobacco (organochlorine, organophosphorus and carbamate insecticides) published in 1970 has been improved by introduction of the dry-column chromatography as cleanup procedure. A new procedure has been developed for the detection of carbaryl and propoxur by gas chromatography. The extraction and cleanup method developed can be used to determine 11 organochlorine, 11 organophosphorus and 3 carbamate insecticides. The procedure can be applied to determine further insecticides and, in addition, fungicides, herbicides and metabolites. The recoveries of added pesticides at 0.5 ppm level are between 75 and 102 %. The coefficient of variation detected with parathion is 4.4 %

Abstract During the attempt to transfer to tobacco a method commonly used to determine metobromuron in foodstuffs, it became apparent that only very small amounts of metobromuron and less than 0.1 ppm 4-bromoanilin were found. Nor did the modification of this method produce better results, because metobromuron, apparently linked to tobacco components, cannot be extracted with aqueous acetonitrile. The tobacco was then distilled under hydrolysing conditions and the 4-bromoanilin released was bound as hydrochloride. After gas-chromatographic separation 4-bromoanilin is determined specifically with the microcoulometer (bromine) and with the Coulson detector (nitrogen). The amount of metobromuron is calculated from the 4-bromoanilin. With this method no difference can be made between intact metobromuron and 4-bromoanilin already metabolised from metobromuron. Recovery is 90 % for 4-bromoanilin and 92 % for metobromuron, the coefficient of variation is 3.0 %. In cigarettes whose tobacco had grown in soil which had been treated with 4 kg of Patoran per hectare before transplanting, a mean of 5.8 ppm metobromuron was found by this procedure.

AbstractThe author's method (developed in 1966) for the determination of maleic hydrazide in tobacco has been improved by the introduction of a purification step using activated carbon. Interferences produced by reactive compounds other than maleic hydrazide can thus be eliminated. The procedure proved to be suitable for routine analysis. The coefficient of variation was found to range from 1 to 7 %. Added amounts of maleic hydrazide have been recovered at the 90-105 % level. The accuracy of the procedure could be confirmed by results comparatively obtained in three laboratories

AbstractThe method used in our laboratories since 1965 for the determination of menthol in tobacco and tobacco products has meanwhile been improved and made suitable for series analyses. Menthol is isolated from the mentholated material to be investigated by steam distillation The distillate containing the menthol in question (dissolved in acetone) is directly subjected to gas chromatography for quantitative determination. The recovery was found to amount to 97 %, the coefficient of variation to 1.45 %, and the detection limit to 0.002 mg of menthol per mI.

In einer Literaturübersicht bis etwa 1971 wird auf die Schwerpunkte der Rückstandsanalytik in bezug auf Methoden und Substanzgruppen hingewiesen. Unterstrichen werden Statistik der Probenziehung, Anreicherungsprobleme und Spezifität sowie Sensibilität besonders der GC-Detektoren. Anschließend wird über gemeinsame und eigene Bemühungen zur Lösung des Rückstandsproblemes auf Tabak berichtet. Adaptierte und neue Methoden werden mitgeteilt und ihre Ergebnisse diskutiert.

AbstractA screening method has been developed for the qualitative and quantitative determination of vanillin, ethylvanillin, coumarin and dihydrocoumarin. The compounds are qualitatively determined by thin-layer chromatography after extraction of tobacco and purification of the extract. The quantitative determination is made by gas chromatography: Coumarin and dihydrocoumarin are determined directly and vanillin and ethylvanillin after silylation in the form of trimethylsilyl derivatives. Detection limit: thin-layer chromatography = 1 µg, gas chromatography = 0.02 µg. The coefficient of variation of the results obtained amounts to 2.4 % for vanillin and to 6.7 % for coumarin

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A thin-layer chromatographic method has been developed for the qualitative and quantitative determination of carbamate residues on tobacco. The method's inferior limit of detection is 80 ng for Carbaryl and 200 ng for Undene. The coefficient of variation of the results is 5.3 % for Carbaryl and 7.7 % for Undene.