DETERMINATION OF SULFATE-SULFUR IN PLANT-TISSUE BY INDUCTIVELY COUPLED PLASMA SPECTROMETRY

A method is described to accurately assess inorganic sulfur concentration in plant tissue by ICP spectrometry using a weak anion exchange resin. The procedure is faster and capable of much higher precision than standard gravimetric analysis. The method was tested using four plant tissues: sugar beet, alfalfa, tomato and prune; which were extracted for sulfate-sulfur (SO4-S) with two percent acetic acid. Extracts were passed over a weak anion exchange resin where SO4-S is bound. The column was washed with 0.1N HCl to remove non-SO4-S compounds, S04-S was eluted with 1.0N HCl and determined by ICP Spectrometry. Sulfate-sulfur recovery was assessed using both inorganic and organic sulfur spiking and comparison with gravimetric analysis. Results conclusively show that this procedure effectively isolates SO4-S on four plant materials ranging from 250–6000 ug/gm SO4-S. There is minimal recovery from organic sources associated with the extract. © 1990, Taylor & Francis Group, LLC. All rights reserved.