海洋沉积物孔隙水中阴阳离子含量的离子色谱法分析方法

ION CHROMATOGRAM METHOD FOR ANALYZING ANIONS AND CATIONS IN PORE WATER FROM MARINE SEDIMENTS

分别采用Metrosep A Supp4-250型阴离子柱和Metrosep C 2-150型阳离子柱,以1.8 mmol/L Na2CO3+1.7 mmol/L NaHCO3和4 mmol/L酒石酸+0.75 mmol/L吡啶二羧酸为阴阳离子淋洗液,用离子色谱仪来测定海洋沉积物孔隙水中阴离子Cl-、Br-和SO42-浓度和阳离子Na+、NH4+、K+、Ca2+、Mg2+的浓度。特别是针对高Cl-和高Na+背景下Br-和NH4+的测定做了专门分析,得到了较理想的结果,建立了一套离子色谱法测定海洋沉积物孔隙水中常见的阴阳离子含量的实验方法。

We use ion chromatogram technique to determine the anion and cation ion concentrations in pore waters. Metrosep A Supp4-250 type column and 1.8 mmol/L Na2CO3 ＋1.7 mmol/L NaHCO3mixed solution in anion system are used to determine concentrations of Cl^-, Br-and SO4^2- in pore water, and Metrosep C 2-150 type column and 4 mmol/L tartaric acid＋0. 75 mmol/L C7H5NO4 mixed solution in cation system are used to determine concentrations of Na^＋ , NH^＋ , K^＋ , Ca^3＋ and Mg^2＋. The results indicate that correlation coefficient between measured and standard values for each ion in standard solutions preponderates over 0. 999. The detection limit is less than 0. 5 mg/L, and the relative standard deviation is better than 3%. In particular, we carried out special experiment to measure Br^- concentration under high Cl^- concentration background as well as NH4^＋ concentration under high Na^＋ concentration background. Right now, a tentative ion chromatograph method for analyzing concentrations of cations and anions in pore water from marine sediments has been established in our lab. This method has been proved to be rapid, simple, sensitive, and accurate.