【摘要】 本文建立了准确、快速、经济的控制缓释肥料中尿素态氮的测定方法。采用自制黄豆脲酶水解液,于pH7.0的磷酸盐缓冲体系中水解尿素,以奈氏试剂为显色剂,用分光光度法测定尿素态氮。该方法在0～2.50μg/mL范围内符合比耳定律,检出限为0.01μg/mL,用于控制缓释肥料中尿素态氮的测定,回收率在96.2%到100.8%之间,与商品脲酶测定结果接近。更多还原

【Abstract】 A accurate, rapid and economic method for the determination of urea-nitrogen in controlled release fertilizers was developed. The urea was hydrolysised in （pH 7.0） buffer medium, and the urea-nitrogen was determined by Spectrophotometry with Nessler’s reagent as the chromogenic reagent. Beer’s law is obeyed in the range of 0～2.50 μg/mL with λ_max=420 nm. The detection limit is 0.01 μg/ml. This assay was applied to determinate urea-nitrogen in controlled release fertilizers with recovery ranging from 96.2% to 100.8%.更多还原