Evaluation of a closed vessel acid digestion method for plant analyses using inductively coupled plasma spectrometry

Abstract

A simple acid digestion procedure has been evaluated which utilized a closed, teflon container with HNO₃ and plant tissue placed into an initially cool oven which was brought to 110°C overnight. The accuracy and precision of the method were evaluated for a wide variety of plant materials obtained from NBS and a regional plant tissue exchange program. There were significant differences between the proposed method and the standard HNO₃‐HClO₄ digestion with Al, Fe, Cu, and Mg. However, the data comparison of the HNO₃ closed vessel digestion results to NBS plant reference materials showed significantly lower values only with Al and Fe. Comparison of this method to the plant materials analyzed by laboratories in a tissue exchange program showed good agreement. Thus, this method appears accurate and precise for plant tissue analyses of Ca, Mg, P, K, S, Cu, Mn, Na, Zn and B using inductively coupled plasma spectrometry. It appears to perform as well as most other methods utilized by western plant tissue laboratories for Fe also.