重铬酸钾氧化—分光光度法测定土壤中有机碳的方法优化
晏立衡1
作者信息
- 1. 上海市环境监测中心,上海 200235
- 折叠
摘要
以现行有效的重铬酸钾氧化—分光光度法测定有机碳为基础,优化校准曲线绘制条件、加热温度、加热时间及消解定容后样品静置时间,准确快速得到土壤中有机碳含量.对标准样品和实际样品进行测试,结果表明:校准曲线无需加热;加热温度为135℃,加热时间为20 min,消解定容后无需静置,直接离心测试,即可得到符合质量控制要求的有机碳测定结果.对优化后的方法进行验证,方法检出限为0.06％,相对标准偏差为2.1％～3.9％,相对误差为-4.7％～1.8％,可满足实际工作需要.
Abstract
Based on the current effective potassium dichromate oxidation-spectrophotometry method for the determination of organic carbon,optimize the calibration curve drawing condition,heating temperature,heating time,and sample standing time after digestion to accurately and quickly obtain the organic carbon content in soil.By testing both standard and actual samples,the results showed that the calibration curve was drawn without the need for heating;heating temperature of 135 ℃,heating time of 20 minutes,and the digestion and fixed volume samples are centrifuged directly for testing,without standing,which can obtain organic carbon determination results that meet quality control requirements.By validating the optimized method,the detection limit is 0.06％,the relative standard deviation is 2.1％-3.9％,and the relative error is-4.7％-1.8％,which can meet practical needs.
关键词
校准曲线/加热温度/加热时间/静置时间/有机碳Key words
calibration curve/heating temperature/heating time/standing time/organic carbon引用本文复制引用
出版年
2024
NETL
NSTL
万方数据