Abstract:A rapid and accurate detection method for urea in fermented wine was developed by preparation of immobilized urea membrane using gelatin and chitosan as embedding materials, dialysis membrane as the carrier, and glutaraldehyde as crosslinking agent.The membrane was then applied to determinate actual samples, combined with the ammonium ion selective electrod. The urease immobilized conditions and the response performance of the urea sensor were also studied. For urease enzyme immobilization process, the most suitable glutaraldehyde concentration was 0.05% and the optimum crosslinking time was 1.5 h. The urea sensor showed good linearity (R2>0.999), good repeatability (RSD=1.45%), and high reliability, the most suitable temperature and pH were 40 ℃ and 5.0, respectively. In addition, the linear response range and detection limit of this method were found as 2~50 mg/L and 0.5 mg/L, respectively. The multi-usage urease membrane can be renewed, thus reducing the measurement cost and realizing the urea rapid determination in fermented wine under the fermented acidic environment, and providing a technical support for the control of, nutrition, quality and safety of fermented wine.
