一种测定土壤与环境中有效硼的新方法

The Improvement of the Determination Method of Soil Available Boron in the Experiment Course of Soil and Environment Analysis

长期的土壤与环境分析实验教学实践发现,目前农业高等院校在测定土壤有效硼时一般采用甲亚胺-H酸比色法,这种方法相比其他方法操作比较简单,大学生容易掌握实验应用的各种仪器,更适合高等院校本科实验教学。但传统方法在浸提和显色环节存在操作步骤复杂、实验时间长、实验成本高、条件不宜控制和失败率偏高等缺点,多次实验证明,用聚乙烯塑料自封袋代替昂贵的石英三角瓶,用水浴法代替直接煮沸法进行土壤有效硼的浸提;用甲亚胺-H酸溶液代替甲亚胺-H酸成品进行有效硼显色。改进后的测量方法的精密度和稳定性,都符合土壤有效硼测定的要求和标准,并且改进的新方法可操作性强,实验者容易掌握,极大减低了实验失败率。并且这种土壤有效硼测定的新方法可以一次进行较多样品的处理,既缩短了实验时间,又降低了土壤有效硼测定的实验成本,,提高实验成功率。用国家土壤有效态一级标准物质进行测试比较结果表明,新方法变异系数12.54%,较好地提升和改进了土壤与环境分析实验教学效果。

IIn the long-term practice of the experimental course of Soil and Environment Analysis, it is found that the spectrophotometric determination of soil available boron with azomethine H is simple to operate and the instruments used are easy to learn by students, which is more suitable than the other methods for the undergraduate experimental teaching in the university. How ever, there are some deficiencies during the boron extracting and coloring in this method, such as the complicated operating procedure, the long experimental time, the high cost, the challenging of condition control and the high failure rate. we analyzed the shortcomings of this method in detail and presented the improved method. Using the improved method to do the experiment, it is not only more convenient for students to operate, but also can shorten the experimental time, reduce the cost, and improve the success rate of the experiment. Comparing the test of soil effective state of national standard substances, the variation coefficient of the new method was 12.54%, the new method innovates and promotes the teaching quality of the experimental course of Soil and Environment Analysis.