Determination of macronutrients in fertilizers

INTRODUCTION

The method is used for the determination of the mass fraction of all primary and secondary nutrients (macronutrients) in fertilizers by capillary electrophoresis. The method allows the determination of such macronutrients as ammonium nitrogen (ammoniacal nitrogen, NH₄-N), nitrate nitrogen (NO₃-N), phosphorus (P or P₂O₅), potassium (K or K₂O) as well as sodium, magnesium, calcium, sulfur, chlorine (chloride), fluorine (fluoride).

MEASURING METHOD

The measurement method is based on extraction of the components from a sample by water and determination of cations (ammonium, potassium, sodium, magnesium, calcium) and anions (chloride, sulfate, nitrate, fluoride, phosphate) by capillary electrophoresis with indirect UV detection at the wavelength of 254 or 267 nm.