Determination of wine amines by HPLC using automated precolumn derivatisation with o-phthalaldehyde and fluorescence detection

Summary A method was developed for the determination of the most important wine amines, histamine, tyramine, putrescine, cadaverine, isoamylamine und-phenethylamine in wine. Amine derivatives were formed automatically by drawing 1 l of wine, 1 l ofo-phthalaldehyde reagent and 5 l of pH 10.4 buffer solution into an injection needle. The reactants were mixed by drawing the liquid back and forth in the needle for 2 min. The derivatives were determined by liquid chromatography using the reversed-phase technique and fluorescence detection. The detection limit for amines ranged from 0.006 to 0.05 mg/L and the determination limit for amines in wine ranged from 0.5 to 1 mg/L, depending on the amine. The total time required by the analysis is 30 min.

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Automatisierung der Bestimmung von Weinaminen mit Hilfe der in der Injektionsspritze erfolgenden OPA-Derivatbildung und Fluorescenz-Flüssigchromatographie

Zusammenfassung In der Untersuchung wurde eine Methode für die wichtigsten im Wein vorkommenden Amine entwickelt: Histamin, Tyramin, Putrescin, Cadaverin, Isoamylamin und-Phenethylamin. Von den zu bestimmenden Aminen wurden durch Aufnahme von 1 l Wein, 1 l OPA-Reagens und 5 l Pufferlösung, pH 10,4, in der gleichen Injektionsspritze deren Derivate gebildet. Die Reaktionspartner wurden durch 2 min Hin- und Herziehen in der Spritze miteinander vermischt. Die Bestimmung der Derivate erfolgte flüssigchromatographisch unter Anwendung von Umkehrphasentechnik und Fluorescenznachweis. Die Nachweisgrenze der Aminen variierte je nach Amin zwischen 0,006 und 0,05 mg/L und die entsprechende Bestimmungsgrenze im Wein zwischen 0,5 und 1 mg/L. Die für die Analyse benötigte Gesamtzeit beträgt 30 min.

     

Smoking cessation by socioeconomic status and marital status: the contribution of smoking behavior and family background.

We studied socioeconomic status and marital status as predictors of smoking cessation, adjusting for previous smoking behavior and family background by using a large Finnish prospective twin dataset unselected for smoking behavior. The data were collected by postal surveys in 1981 and 1990, and the sample comprised 3,069 current smokers, of whom 20% had quit smoking by 1990. Logistic regression analyses of all twin individuals and conditional logistic regression analysis of discordant pairs were used to predict smoking cessation. High education predicted smoking cessation among both men (OR=2.32, 95% CI=1.31-4.10) and women (OR=3.98, 95% CI=1.85-8.51) as did high social class among women. Additionally, starting at a late age, smoking a small number of cigarettes per day, and a low level of nicotine per cigarette predicted cessation. Socioeconomic differences in cessation diminished only slightly when we adjusted for smoking behavior factors. Among the twin pairs who were discordant in terms of smoking cessation, the twin who continued smoking also smoked more on average at baseline (men: OR=.94, 95% CI=.89-.99; women: OR=.82, 95% CI=.71-.94). The male twins who continued smoking had a smaller probability of getting married during the follow-up than had the cotwin who had quit smoking (OR=3.91, 95% CI=1.02-15.02). Indicators of socioeconomic status were important predictors of smoking cessation even when we adjusted for previous smoking behavior. For men, marriage was associated with an increased probability of cessation     

Producing illumination-independent additively mixed colors by diffractive optics

We apply transmission gratings under Littrow incidence to produce polychromatic colors by additive color mixing. Parametric optimization of gratings is employed to produce high efficiency. In addition, we show that the system can yield the same color from a wide variety of spectra; i.e., the system can produce metameric colors.     

The association of noise sensitivity with coronary heart and cardiovascular mortality among Finnish adults

The association of coronary heart and cardiovascular mortality with noise sensitivity was studied. We also investigated how this association is affected by self-reported lifetime noise exposure. In 1988 a case-control study, based on the Finnish Twin Cohort, was carried out to investigate the relationship between noise and hypertension (n=1495). Potential confounders were obtained from questionnaire in 1981 for the same individuals. Data on deaths and causes of death were obtained from record linkage to the nationwide register of death certificates. All deaths that occurred among the study population during the 15 years of follow-up were classified as being due to all causes (n=382), to cardiovascular diseases (n=193), including the number of deaths due to coronary heart diseases (n=111) and to other causes than cardiovascular diseases (n=189). Cardiovascular mortality (Hazard ratio 1.80, 95% CI 1.07-3.04) was significantly increased among noise-sensitive women. Among men, there were no statistically significant effects. Noise sensitivity may be a risk factor for cardiovascular mortality in women.