Determination of the silicon concentration in plant material using Tiron extraction

• The quantification of silicon (Si) in plants generally requires a digestion procedure before the determination of the dissolved Si concentration by spectrometric analysis. Recent procedures produce rapid and accurate measurements, but are based on either hazardous chemicals or sophisticated instrumentation. • Here, we describe a simpler procedure using Tiron. Tiron [4,5‐dihydroxy‐1,3‐benzene‐disulfonic acid disodium salt, (HO)₂C₆H₂(SO₃Na)₂] is currently used as a selective extractant for amorphous silica in soils. Because Si in the shoots is mostly composed of amorphous opaline silica particles (i.e. phytoliths), we tested the Tiron extraction procedure for plants. • Our results are critically discussed in relation to two other standard procedures: electrothermal vaporization determination and high‐temperature lithium‐metaborate digestion. • We demonstrate that Tiron extraction is an alternative method which allows the rapid, safe and accurate quantification of Si in shoots of various plants covering a wide range of Si concentrations.