Determination of Different Inorganic Iodine Species in Soils by High Performance Liquid Chromatography-Inductively Coupled Plasma-Mass Spectrometry

KeyWord:high performance liquid chromatography-inductively coupled plasma-mass spectrometry(HPLC-ICP-MS)  soil  inorganic iodine  species

Abstract:

      A method was established for the separation and determination of different inorganic iodine species(iodide and iodate ions) in soils by high performance liquid chromatography and inductively coupled plasma-mass spectrometry(HPLC-ICP-MS).The sample was ultrasonically extracted with 4 mmol/L tetrabutylammonium hydroxide(TBAH) solution.After centrifugation,the sample was purified with Na column and 0ª±22 ¦Ìm hybrid filter membrane.The determination was performed by HPLC-ICP-MS combined with a Dionex IonPac AS16 anion exchange column using 50 mmol/L ammonium carbonate(pH 9.8) as mobile phase.Results indicated that the linear ranges for two inorganic iodine species(I- and IO-3) ranged from 10 ¦Ìg/L to 500 ¦Ìg/L with correlation coefficients(r2) greater than 0.999.The limits of detection for the two iodine species were 0.05 ¦Ìg/L and 0.1 ¦Ìg/L,and the limits of quantitation were 2 ¦Ìg/L and 5 ¦Ìg/L,respectively.The method was applied in the determination of two inorganic iodine species in soils,with spiked recoveries of 83.8%-108%and relative standard deviations(RSD) of 0.5%-3.0%,which were better than those obtained by the oscillation extraction.With the advantages of rapidness,high efficiency,good reproducibility and high sensitivity,the method is suitable for the determination of different inorganic iodine species in soils.