分光光度法测定树脂包衣尿素溶出的研究

Colorimetric estimation of urea release rate in coated urea

研究了对二甲氨基苯甲醛分光光度法应用于树脂包衣尿素养分溶出测定的可行性。对二甲氨基苯甲醛与尿素在酸性条件下生成黄色物质,其吸光值与尿素溶液的浓度成正比。结果表明,该方法与蒸馏后滴定法测定尿素相关性非常好,测定过程中缩二脲和硝态氮、铵态氮的干扰少。树脂包衣尿素养分溶出测定期间,尿素样品分解量少,分光光度法与蒸馏后滴定法的测定结果相关性非常好。试验证明两种方法测定包衣尿素溶出均可给出满意的结果,但分光光度法更快速、简便,适合于大批量样品的测定。

This article refers to dimethylamino-benzaldehyde spectrophotometry method used in the detection of coated urea release rate. Dimethylamino-benzaldehyde and urea react to form a stable yellow complex in thin hydrochloric acid solution, the color could maintain for more than 24 hours. Biuret, nitrate and amonium had little interference. During the examination of coated urea released rate, the urea sample decompose little, the results using spectrophotometry method and the digest-distill method had good correlationship. The two methods could all give out satisfied results, but spectrophotometry method was more simple and rapid in operation, and suit to mass samples.