基于光度法的高精度海水pH值测量系统

基于光度法的海水pH值自动测量系统测定速度快,精密度高,是海洋酸化和碳循环研究急需的测量装置.本研究以光度法和流动注射分析技术为基础,通过整合泵阀流路体系、LED光源、流通池和光谱仪,研发了海水pH值自动测量系统.本系统在分析过程中不易产生气泡,利用指示剂在样品中的浓度变化校正指示剂的加入带来的测量偏差,操作简单方便,测量一个样品用时约为1.5 min,精密度为0.0013,准确度为0.0059,可在实验室或调查船中对所采集的海水快速地进行高精度pH值测量.

A Spectrophotometric System for High Precision Measurement of pH of Seawater

Spectrophotometric seawater pH measurement system is an urgent need of device due to its quick speed and high precision. Based on spectrophotometric method and flow injection analysis technique, an automated system for pH measurement of seawater was developed by integrating pump and valve flow path, LED light source, flow cell and spectrophotometer. This measurement system effectively avoided bubbles. The indicator of concentration gradient in the seawater sample was used to correct for the pH perturbation caused by the indicator, thus the operation of system was simple and convenient. with this system, only 1. 5 min was needed for a sample measurement with a precision of 0. 0013 pH units and an offset of 0. 0059 pH units. This system could be used for the rapid determination of pH of seawater collected by laboratory or research ship with high precision pH values.