Chemical interferences in the determination of manganese in plant material by atomic-absorption spectroscopy

Abstract

Combinations of calcium plus magnesium with sulphate may cause low results in the determination of manganese by atomic-absorption spectroscopy. Maximum depression of manganese absorbance is noted when the mole ratio of calcium plus magnesium to sulphur is 1:1. When plant samples are digested with a mixture of nitric and perchloric acids, low results are obtained only for those materials which are low in calcium plus magnesium and high in sulphur, e.g., grain; correct values are obtained by incorporating lanthanum chloride in the solution. If sulphuric acid is used in the digestion, very low values are obtained and addition of lanthanum chloride effects little improvement.