微流池多光程土壤有效态氮磷测定方法研究

农业面源氮磷污染是当前地表水体污染主要来源,而土壤有效态氮磷测试大都依赖于流动分析仪在实验室完成,无法满足个性化土壤有效态氮磷现场测定需求。建立了一种微流池多光程的土壤有效态氮磷测定技术,通过柔性化参数设置,实现不同土壤有效态氮磷测试规范和现场测试。以广东省韶关市农业科学研究所和北京市农林科学院提供的26个样品为例进行有效态铵态氮、硝态氮和磷测定验证。实验结果表明,微流池多光程土壤有效态氮磷测定方法中有效态铵态氮、硝态氮和磷的检出限(LOD)分别为0.0086、0.0094和0.0078 mg/L,相对标准偏差(RSD)分别为0.80%、5.7%和0.90%,加标回收率在92.0%~103%,平均单样品测试时间6 min。测试过程自动化,极大地提升了土壤有效态氮磷测定效率和测试结果准确性,为农业面源污染防治提供技术支撑。

Determination of Available Nitrogen and Phosphorus in Soil using a Micro-tube with Multi-optical Length

Nonpoint?source?pollution (NPSP) from agricultural runoff threatens drinking water quality. Currently, both the available nitrogen and phosphorus are measured by the flow analysis method in the laboratory. This method used in Laboratory cannot meet the requirements of the available nitrogen and phosphorus in field. The paper proposes a determination method of soil available nitrogen and phosphorus using a micro-tube with multi-optical length, which can flexibly set parameters to meet different soil extraction systems and test specifications, and then achieve on-site testing of available nitrogen and phosphorus. In this paper, the measurements of ammonium nitrogen, nitrate nitrogen and available phosphorus in 26 soil samples were arranged to verify the performance of a measurement system using a micro-tube with multi-optical length. The soil samples were provided by the Shaoguan Institute of Agricultural Sciences in Guangdong Province and the Beijing Academy of Agriculture and Forestry Sciences. The test results show that the detection limits (LOD) of ammonium nitrogen, nitrate nitrogen and available phosphorus are 0.0086 mg/L, 0.0094 mg/L and 0.0078 mg/L, respectively, the relative standard deviations (RSD) are 0.8% ,5.7% and 0.9%. The spiked recoveries is obtained to be 94%~103%, The average test time for a sample is 6 min. the measurement process is running automatelly, which greatly improves the measurement efficiency and accuracy.Therefore, it can provide technical support for the prevention and control of agricultural non-point source pollution.