This method quantitatively determines the amount of sulfate-sulfur (SO4-S) in botanical materials by extraction with a solution of 2 % acetic acid. Sulfate contained within the extract is bound to an anion exchange resin, organo-sulfur compounds are removed by washing with 0.1N HCl, and sulfate is eluted with 1.0N HCl. The sulfur content of the extract is determined by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). The method may be semi-quantitative on some botanical materials which have a high anion exchange capacity or in samples where sulfate is not the most significant anionic form of sulfur. The method has a detection limit of 10 ppm.
Sample amount requested: 5 g
Questions concerning limited sample size can be answered by the UC Davis Analytical Laboratory.
Littlefield, E. S., Miller, R. O. and Carlson, R. M. 1990. Determination of sulfate-sulfur in plant tissue by inductively coupled plasma spectrometry. Commun. Soil Sci. Plant Anal. 21:1577-1586.