海水溶解氧测定方法的研究

溶解氧是海洋调查中化学要素部分的重要项目之一。“海洋调查规范”目前仍采用经典的Winkler修正法,由于此方法操作费时,劳动强度大,而且会引起主观误差,因此迫切要求改用仪器分析方法以提高海洋调查工作的质量。     

薄层流动玻炭金膜电极阳极溶出伏安法测定海水中痕量银

本文提出了测定海水中痕量银的新方法.实验结果表明,用玻炭金膜电极与薄层流动示差脉冲溶出法相结合,改善了玻炭电极的重现性,提高了测定银的灵敏度.实验中,控制流速为1.8-2.0毫升/分,电极电位取-0.6伏,银峰电位在0-+0.9伏之间,灵敏度、线性、重现性和干扰实验均获得较好的结果.海水不经预富集,在天然海水中加入纯硝酸至酸度为0.025M,即可进行测定.实验可得到清晰的示差脉冲阳极溶出峰,方法灵敏度为1×10-10M,重复测定六次的标准偏差小于±2%,回收率为85-96%.应用本方法测定了厦门港海水、外海海水等水样,均得到满意的结果.     

RESEARCH ON DETERMINATION OF DISSOLVED OXYGEN IN SEAWATER

Based on the principle of laminar flow-constant potential-chronocoulometry, this article presents a new method of determining the dissolved oxygen in seawater with considerable success. A new model of electrochemical sensor has been designed for this purpose.The sensor has the advantage of overcoming hysteresis and "outskirts effect", thus increasing its stability and prolonging its use to 1-2 years.In connection with this new method a new model SY-1 integrating microcoulorneter with digital display is designed.It is a fast (a sample/2 min) and accurate (±1 - 1.5%) method, suitable for use in the laboratory on board a ship.