Department of Applied Science, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand.
Department of Applied Science, Faculty of Science, Prince of Songkla University, Songkhla 90112, Thailand.
Food Chem. 2020 Jul 30;319:126545. doi: 10.1016/j.foodchem.2020.126545. Epub 2020 Mar 2.
A sol-gel urea colorimetric method was developed for the determination of urea in feedstuffs. The sol-gel platform contained p-dimethylaminobenzaldehyde (p-DMAB) as the reagent entrapped within polymer network. The urea analysis relied on the formation of Schiff base under acidic conditions. The colorimetric product was imaged with a Smartphone. Under optimized conditions, the calibration curve for urea was linear over the concentration range of 2.5-100 and 100-1000 mg L with a good coefficient of determination (r > 0.99). The limit of detection (LOD) and limit of quantification (LOQ) were 0.1 and 0.5 mg L, respectively. The intra-day and inter-day precisions were 0.83-3.01%RSD and 2.20-5.47%RSD, respectively. Accuracy of urea analysis ranged from -1.15 to 2.76%. The proposed method was stable for at least 90 days. The amount of urea in feedstuff sample was determined. The developed method is easy to use with small samples and reagent consumption in field conditions for monitoring the quality of feedstuff.
一种用于饲料中尿素测定的溶胶-凝胶脲比色法。溶胶-凝胶平台包含 p-二甲氨基苯甲醛（p-DMAB）作为试剂，被包埋在聚合物网络中。尿素分析依赖于在酸性条件下形成希夫碱。显色产物用智能手机进行成像。在优化条件下，尿素的校准曲线在 2.5-100 和 100-1000 mg/L 的浓度范围内呈线性，相关系数（r）大于 0.99。检测限（LOD）和定量限（LOQ）分别为 0.1 和 0.5 mg/L。日内和日间精密度分别为 0.83-3.01%RSD 和 2.20-5.47%RSD。尿素分析的准确度范围为-1.15 至 2.76%。该方法至少稳定 90 天。测定了饲料样品中的尿素含量。该方法易于使用，在现场条件下可用于监测饲料质量，所需样品和试剂的用量较少。
