摘要
自从流动注射分析技术提出以后,很多作者用于测定水中氨氮的研究。其主要测定方法有奈氏试剂法、气体扩散法、电测法等。这些方法有的检出限较高,不适于海水中NH_4^+-N的测定,有的则还没有直接应用于海水介质中。Johnson等提出了反流动注射分析技术,利用样品分散度低的特点,使分析灵敏度显著提高,并对海水中NO_3^-,NO_2^-,PO_4^(3-),SiO_3^(2-),的测定进行了研究。鉴于我国调查规范的要求,本文利用流动注射技术对次溴酸钠氧化法进行了研究,并通过因子设计及单纯形最优化选择等条件实验,得到了满意的结果。
The method for the determination of seawaler ammonia, being oxidized to nitrite by sodium hypobromite, with rF1A is described. By means of factor design and simplex, the opti mum conditions for the determination are reached. The oxidation ratio over 80% and the detection limit with 0.13μmol/L are achieved. With the operation automation the precision of the spectuophotometry is also improved significantly with the variation coefficient of 2.2% at the level of 2.23μmol/L. The salt effect is less than 2% and the recovery for control samples is about 102%. The dynamic range of the method can expand to 20μmol/L and the measurement rate of 60 samples per hour has been gotten in. Amino acids up to 3 mg/L do not interfere the determination of ammonium ion. The samples from Qingdao coastal zone were taken and determined with the rFIA and manual method of routine analysis. The results obtained by the two methods are comparable. The better reproducibility of rFIA method has been noticed.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
1991年第4期389-395,共7页
Oceanologia Et Limnologia Sinica
