海洋沉积物孔隙水总碱度的现场分析方法

海洋沉积物孔隙水总碱度及其分布对海洋天然气水合物的调查研究具有重要意义.孔隙水总碱度异常对于判断天然气水合物的存在具有重要的指示作用.建立了利用微量水样品测试总碱度的方法,将2.00 mL孔隙水样品加入10.00 mL已知总碱度的海水样品中,使用盐酸标准溶液滴定、pH计监控法测定混合溶液的总碱度,然后计算出加入孔隙水样品的总碱度.方法所需样品量少,测定结果的相对标准偏差小于2％(n=12),方法简便可行,可用于船上海洋沉积物孔隙水总碱度的现场测定.

A Determination Method for the Alkalinity of Pore-Water in Marine Sediment

The distribution of alkalinity in pore-water of the marine sediments is an important tool for the research of gas hydrate. A determination method for the alkalinity in pore-water was developed. A mixture was made with 2.00 mL pore-water sample and the 10.00 mL sea water whose alkalinity has been determined in previous, pH electrode as a monitor metee, the alkalinity of the mixture was determined by the titration with HCl-standard solution; then alkalinity of the pore- water was calculated. Only about 2 mL pore-water sample was consumed in the determination. The RSD was less than 2%（n=12）. The method is suitable for determination of alkalinitv in pore-water of the marine sediments on the spot.