森林土壤有效硼的测定方法研究
A Study of the Method for the Determination of Available Boron in Forest Soil
-
摘要: 本文通过单因素试验,利用稳定度、精度和变异系数作为评价指标,优化土壤样品浸提液中硼含量测定方法。基于硼在弱酸性水溶液中易与甲亚胺生成黄色络合物,在420 nm具有特征波长,在0~10 mg·10 ml-1测定范围内符合朗伯-比尔定律,灵敏度为0.0013mg·cm-2;同时,浸提液可直接利用电感耦合等离子体发射光谱(ICP-AES)进行测定,其检出限为0.0041,变异系数为3.49%,通过与国家土壤有效态一级标准物质测试相比较,ICP-AES、比色法变异系数分别为4.24%、20.82%,测定结果ICP-AES优于比色法结果。Abstract: In this paper,studies were mainly made of the soil sample by boiling water extraction for 5 minutes for the purpose of determination of boron content. The method was used to form a yellow complex by boron and azomethine in weak acidic solution in order to make a colorimetric determination,in the range of 0~10 mg·10 ml-1 by use of the Lambert-Bill law determination method, and the sensitivity was 0.0013 mg·cm-2. The extraction was directly determinated by inductively coupled plasma atomic emission spectrometry(ICP-AES),the detection limit was 0.0041,and the variation coefficient was 3.49%. Comparing the test of soil effective state of national standard substances,methods of coefficient of variation were 4.24% and 20.84%. The test results of the ICP-AES were better than those of the colorimetric method.