酶电极法测定发酵酒中尿素的含量

Detection of Urea Content in Fermented Wine by the Enzyme Electrode

摘要:

为实现准确、快速检测发酵酒中尿素含量，本文以明胶和壳聚糖为包埋材料，透析膜为载体，戊二醛为交联剂，用包埋交联吸附相结合的方法制作了固定化脲酶膜，结合铵离子选择性电极实现了尿素含量的快速测定，研究了脲酶固定化的条件和尿素传感器的响应性能，并应用于实际样品的测定。实验表明：脲酶固定化最适戊二醛浓度为0.05%，最适交联时间为1.5 h；尿素传感器最佳使用环境为温度40 ℃，最适溶液pH值5.0,线性范围为2~50 mg/L，最低检测限为0.5 mg/L，线性良好（R2>0.999），重复性好（RSD=1.45%），可靠性较高。此方法每片脲酶膜可进行多次测量，且可更换，降低了测量成本，可用于实现酸性环境下发酵酒中尿素含量的快速检测，为控制发酵酒的营养、质量及食用安全提供技术支持。

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.