Mineral Composition Analysis: Measuring Anion Uptake and Anion Concentrations in Plant Tissues

This chapter describes two basic complementary methods relevant to at least three major macronutrients in plants: NO ₃ ⁻ , SO ₄ ²⁻ , and phosphate. The first method is the simultaneous determination of tissue content of the oxyanions, NO ₃ ⁻ , SO ₄ ²⁻ , and phosphate by HPLC, and the second is the determination of tissue uptake (transport) capacity for these same oxyanions. NO ₃ ⁻ , phosphate, and SO ₄ ²⁻ , as well as other anions including chloride, malate, and nitrite are extracted from milligram quantities of plant tissue and are separated and quantified in a single chromatographic (HPLC) run. Information on uptake (flux) of these same anions through the roots may be obtained using isotopically labeled elements, enabling transport capacity of roots and subsequent translocation to shoot tissues to be determined.