人工海水及陈化天然海水在营养盐测定中的本底值评估

Background nutrient salt concentration determination of artificial and aged natural seawaters used in seawater nutrient analysis

营养盐是海洋调查中必不可少的测量参数。利用流动注射分析仪测定海水营养盐含量通常需要使用与样品盐度相近的人工海水或陈化天然海水作为配制标准曲线的基液和间隔样品的载液。本文测定了Sigma、Aladdin、国药优级纯氯化钠盐溶液和陈化西太平洋海水中亚硝酸盐、硝酸盐、铵盐、磷酸盐及硅酸盐含量的本底值。结果表明:三个品牌的氯化钠盐溶液中除磷酸盐外,亚硝酸盐、硝酸盐、铵盐和硅酸盐的含量均有不同程度的本底值,而陈化西太平洋海水除了亚硝酸盐和硅酸盐外,其它三项营养盐在测定误差范围内基本不存在本底值。

Nutrient assay is essential in the routine oceanographic surveys.The nutrients of seawater are determined on a continuous flow analyzer usually requires artificial seawater or aged low-nutrient natural seawater as the basal solution of standard calibration and the rinsing solution of the assaying system when seawater sample is changed.In this study,the concentrations of components(phosphate,nitrite,nitrate,ammonia nitrogen and silicate)in Sigma,Aladdin and Sinopharm sodium chloride(GR grade)solutions and aged West Pacific seawater were determined.The results showed that the concentrations of nitrite,nitrate,ammonia nitrogen and silicate varied in the three commercial sodium chloride salt solutions except phosphate.In contrast,the concentration of silicate was relatively high and trace amount of nitrite was found while the other three nutrients were not detectable in the aged West Pacific seawater.