海水五参数原位营养盐分析仪的研制

摘要

A five-parameter in situ seawater nutrients analyzer was developed based on wet chemical reaction principle,combined the spectrophotometric method with flow injection analysis technology.A loop flow was controlled by peristaltic pump and three-way valve in this analyzer,which has the advantages of small size,high-stability,low-reagent consumption and high automation.The linear range,detection limit,accuracy and precision of the instrument were verified through the experiment.The detection linear ranges for nitrite,nitrate,ammonium,phosphate and silicate were 5 ～ 250,10～500,10～500,10～300 and 10～1 000 μg/L,respectively.The minimum detection limits for nitrite,nitrate,ammonium,phosphate and silicate were 0.81,3.01,1.79,2.54 and 3.02 μg/L,respectively.The relative standard deviations (RSD) for nitrite,ammonium and silicate were less than 3％ and the relative standard deviations (RSD) for nitrate and phosphate were less than 5％.The on-site comparison tests between the developed nutrients analyzer and the national standard methods were finished,and the results were basically the same,which indicated that the analyzer was entirely feasible and could reflect the content and changes of the nutrients in the seawater.The nutrients analyzer can be loaded on vessel,stations,buoy platform,and also can be used in the laboratory.%基于湿化学反应原理,将分光光度法与流动注射分析技术相结合,采用三通阀配合蠕动泵控制的环路设计,研制出体积小、稳定性高、试剂用量少、自动化程度高、可以实时在线测量海水中5项营养盐的原位营养盐分析仪.通过实验对仪器的线性范围、检出限、准确度和精密度等进行验证,得到亚硝酸盐、硝酸盐、铵盐、磷酸盐和硅酸盐的线性范围分剐为5～ 250,10～ 500,10～500,10～300,10～1 000 μg/L,最低检出限分别为0.81,3.01,1.79,2.54,3.02 μg/L.在测量范围内亚硝酸盐、铵盐、硅酸盐的相对标准偏差小于3％,硝酸盐和磷酸盐的相对标准偏差小于5％.将研制的海水五参数原位营养盐分析仪与国标法进行现场比测,结果基本一致,能反映各项营养盐的含量及变化.该营养盐分析仪可以搭载到科考船、台站、浮标等平台上进行原位检测,也可以用于实验室测量.