Analysis of Feed Grains and Forages for Traces of Cobalt by Flameless Atomic Absorption Spectroscopy

Abstract

Abstract Flameless atomic absorption spectroscopy (AAS) has been used for the analysis of cobalt (5–200 ppb) in plant material. An ashing temperature study shows that some cobalt may be lost at temperatures >500°C. Direct methods using the carbon rod atomizer have been unsuccessful because of large non-atomic absorption and other interference problems. Calcium, iron, magnesium, and manganese can cause interference. An extraction technique using 1-nitroso-2-naphthol as a chelating agent is recommended for routine analysis. Samples are dry ashed, dissolved in dilute HC1, and extracted with 1-nitroso-2-naphthol-chloroform, and the cobalt level is determined by flameless AAS.