摘要
随着国家对农业面源氮、磷污染防治力度的加大,土壤氮、磷测定技术迫切需要改善。本研究在对常规的扩散对流(Dispersion convection)和强迫对流(Forced convection)流动分析方法基础上,提出了扰动扩散(Perturbation diffusion)流动分析方法,以实现土壤氮、磷全自动化快速测定与分析。扰动扩散流动分析方法是将样品和试剂定量化后集中在化学反应腔中进行反应,然后程序控制蠕动泵对化学反应腔中反应物进行反复扰动,待化学反应完全稳定后流入光电探测单元完成土壤氮、磷含量测定。采用取自湖北潜江的土壤样品对扰动扩散流动分析方法进行了系统验证,实验结果表明,本研究提出的方法与常规紫外可见分光光度法对氮、磷测定相比,基于硫酸钠和碳酸氢钠联合浸提的土壤铵态氮测量值相关系数为0.9155,基于氯化钙浸提的土壤铵态氮、硝态氮和水溶性磷测量值相关系数分别为0.9985、0.9901和0.9911。铵态氮、硝态氮和水溶性磷的检出限分别为0.0554、0.0203 mg·L^(-1)和0.0084 mg·L^(-1),相对标准偏差(RSD,n=7)分别为1.8%、4.8%和1.0%。
Currently,efforts to prevent and control agricultural non-point source(NPS)pollution have been intensively increased in China.Measurement technology of agricultural NPS pollution are urgent required.In this study,a perturbation diffusion flow analysis method was proposed to measure nitrogen and phosphorus automatically,after investigating both conventional dispersion convection and forced convection flow analysis methods.In this novel perturbation diffusion flow analysis,the sample solution and reagents were quantified using a microsyringe pump and then passed into a chemical reaction chamber for mixing.A program-controlled peristaltic pump repeatedly perturbs the reactant in the chemical reaction chamber.After the chemical reaction was completely stabilized,the reactant was injected into the photoelectric detection unit to determine the concentrations of nitrogen and phosphorus.Soil samples collected from Qianjiang,Hubei Province,were used to validate the performance of this novel perturbation diffusion flow analysis method.The experimental results showed that the correlation coefficient of soil ammonium nitrogen measurements with a combined extractant of sodium sulfate and sodium bicarbonate was 0.9155,compared with the conventional UV-Vis spectrophotometry in the laboratory.The correlation coefficients of soil ammonium nitrogen,nitrate nitrogen,and water-soluble phosphorus measurements using the extractant of calcium chloride were 0.9985,0.9901,and 0.9911 with a limit of detection of 0.0554,0.0203 mg·L^(-1),and 0.0084 mg·L^(-1) and relative standard deviation of 1.8%,4.8%,and 1.0%,respectively.
作者
李灿
李振峰
马刘正
张伟
李晓冬
VIJAYA Raghavan
胡建东
LI Can;LI Zhengfeng;MA Liuzheng;ZHANG Wei;LI Xiaodong;VIJAYA Raghavan;HU Jiandong(Henan International Joint Laboratory of Laser Technology in Agriculture Science,College of Mechanical and Electrical Engineering,Henan Agricultural University,Zhengzhou 450002,China;Henan Wendao Optoelectronics Sci&Tech Co.,Ltd.,Zhengzhou 450002,China;Department of Bioresource Engineering,McGill University,Montreal H9X3V9,Canada;State Key Laboratory of Wheat and Maize Crop Science,Zhengzhou 450002,China)
出处
《农业环境科学学报》
CAS
CSCD
北大核心
2022年第8期1846-1854,共9页
Journal of Agro-Environment Science
基金
国家重点研发计划项目(2017YFD0801204)
国家自然科学基金项目(3201890)
河南省外籍科学家工作室项目(GZS2021007)。
关键词
土壤速效氮
土壤速效磷
扰动扩散
化学反应腔
吸光光谱
可调光程
available nitrogen in soil
available phosphorus in soil
perturbation diffusion flow analysis
chemical reaction chamber
absorption spectrum
flexible optical length
