A 3-year study was carried out on the effects of time and temperature on the concentration of ethyl carbamate in wine. The study monitored the changing concentration of ethyl carbamate and of urea and citrulline, which are two major precursors of ethyl carbamate in wine. In addition to the formation of ethyl carbamate, both urea and citrulline decayed in other reactions. Kinetic analysis was carried out to model the formation of ethyl carbamate and its dependence on the concentrations of ethanol, urea and citrulline. This led to the development of an equation that can be used to predict the concentration of ethyl carbamate in wine at the point of consumption, resulting from any given storage time and temperature profile. The results were in good agreement with data obtained from similar studies.

The AOAC official methods for determination of carbon dioxide in wine are time-consuming, relatively complex, and may not be suitable for newer wine products with higher levels of carbonation. A different procedure was collaboratively studied. In this method, NaOH is added to convert CO2, in the wine to the carbonate form. The solution is then titrated with a standard H2S04 solution, and the titer is recorded between pH 8.6 and 4.0. A degassed sample of the same wine is analyzed in the same manner to provide a blank, and that titer is subtracted before the C02 concentration is calculated. Ten laboratories participated in the collaborative study. Each laboratory received 6 pairs of coded samples covering a range of approximately 200 to 380 mg CO2/100 mL. The results from 2 laboratories were excluded as outliers. Although the samples used were commercially produced wines whose carbon dioxide content can vary due to normal bottling equipment variations, average standard deviations for reproducibility and repeatability were 10.97 and 9.96, respectively. The method has been adopted official first action.

A collaborative study was conducted on a chemical or dichromate oxidation procedure for etlianol in wine. The method is based on the steam distillation of ethanol from a 1 ml wine sample into an acidified solution of potassium dichromate, followed by heating 20 min at 60°C to complete the oxidation of the ethanol to acetic acid. The unreacted dichromate is determined by titration with a standard ferrous ammonium sulfate solution, using o-phenanthroline as an indicator. Eleven collaborators participated in the study, of whom seven were familiar with the method and four were not. Eight samples with alcohol content ranging from 11.8 to 23.5% by volume were analyzed. The standard deviations of the reported answers on the identical samples varied from 0.024 to 0.063% in the range of 11.8–20% ethanol and rose to 0,161% in the sample which contained 23.3% ethanol by volume. This reproducibility is better than has been reported with other commonly used methods, and it is recommended that the method be adopted as official first action.

2‐Amino‐pyridine (I), Z‐Amino‐thiazole (VIII) bzw. 2‐Amino‐benzothiazole (XIII) reagieren mit Brombrenz‐ traubensäureester (II) bzw. Brom‐acetessigsäureester (V) zu Imidazolo‐pyridinen (III) und (IV), Imidazolo‐thiazolen (IX) und (XI) sowie Imidazolo‐benzothiazolen (XIV) und (XVI), welche mit Ammoniak zu den entsprechenden Amiden umgesetzt werden können.

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