A Fluorescence‐Based Method for Cyanate Analysis in Ethanol/Water Media: Correlation between Cyanate Presence and Ethyl Carbamate Formation in Sugar Cane Spirit. Issue 10 (12th September 2014) - Ohe, Thiago Hideyuki Kobe
Abstract Based on the fluorescence properties of 2, 4‐(1H, 3H)‐quinazolinedione, a product of the reaction between cyanate and 2‐aminobenzoic acid, a simple, sensitive, selective, and reproducible method for the cyanate analysis in aqueous ethanolic media is proposed. In this method, λexc and λem are 310 and 410 nm, respectively, and the limits of detection and quantification are 2.2 × 10−7 and 6.7 × 10−7 mol/L, respectively. Under optimal conditions (pH = 4.5, 40% ethanol), a concentration of 5.0 × 10−6 mol/L cyanate can be determined in a single measurement, at a 95% level of confidence, with an uncertainty of ± 0.13 × 10−6 mol/L. Cyanide, thiocyanate, chloride, nitrate, and sulfate ions, as well as urea and urethane in concentrations 1 × 103 higher than that of cyanate do not interfere with the measurement. The methodology was applied to cyanate analyses in the different fractions of the sugarcane distillate and the data strongly suggest a correlation between the presence of urea in wine, and the cyanate and ethyl carbamate concentrations in the spirit.