An improved automated colorimetric method for the determination of boron in extracts of soils, soil‐less peat‐based composts, plant materials and hidroponic solutions with Azomethine‐H

Abstract

Abstract Extracts that are coloured, owing to dissolved organic matter, give rise to an interference when boron is determined by the colorimetric Azomethine‐H method. A scheme is presented in which boron is removed from coloured extracts by dialysis. In this way the interference can be removed automatically. The suggested scheme allows hydroponic solutions and extracts of soils, peat‐based composts and plant materials to be analysed without further treatment at a rate of 20 hr‐1. The limit of detection is 0.05ppm B in solution. Recoveries of boron added to extracts from all types of sample were excellent. The effects of some interferences were investigated and found not to be significant under normal working.