离子色谱-电感耦合等离子体质谱联用测定海水中的IO3^-和I^-

Determination of iodate and iodide in seawater by ion chromatography-inductively coupled plasma mass spectrometry

研究了离子色谱-电感耦合等离子体质谱(IC-ICPMS)联用技术直接进样测定海水中IO3-和I-的方法.采用IonPacAG23离子色谱保护柱分离IO3-和I-,以浓度4.0mmol/dm3的KOH为流动相,流量为1.0cm3/min,每个样品的分析时间为2.5min.采用2.5×10-3cm3的进样量,IO3-和I-的检出限分别达到0.6和0.4nmol/dm3,可满足海水中碘形态的定量分析.该方法的IO3-和I-浓度范围在2.0nmol/dm3～2.0μmol/dm3.

A method based on IC-ICP-MS is developed for simultaneous determination of iodate and iodide in seawater using direct injection of sample. Using an IonPac AG23 guard column and an ASRS-ULTRA suppressor for the separation of an eluent 4 mmol/dm3 KOH and 1 cma/min flow rate,the elapsed time is less than 2.5min. Using 2.5 mm3 seawater sample loop, the detection limit is of 0.6 nmol/ dm3 for iodate and 0.4 nmol/dm3 for iodide, which can satisfy the requirement of detection of iodine speciation in seawater. The linear range for both species is between 2.0 nmol/dm3 and 2.0 μmol/dm3.