Determination of total boron in soils by inductively coupled plasma atomic emission spectrometry using microwave‐assisted digestion

Abstract

A method is described in which total soil boron (B) was determined by inductively coupled plasma atomic emission spectrometry (ICP‐AES). The method is based on microwave‐assisted digestion of soil samples with nitric acid (HNO₃), hydrofluoric acid (HF) and hydrogen peroxide (H₂O₂). Excess HF was eliminated by adding silicon (IV) oxide (SiO₂). The B 208.959 nm line was chosen as the analytical line to avoid the spectral interferences of iron (Fe). A detection limit of 0.0045 mg L^‐1 was obtained with the selected analytical line under the optimized operating conditions. Four National Institute of Standards and Technology (NIST) standard reference materials (three soils and one river sediment) and four different type of practical soils were analyzed to test the reliability of the method. The total B concentration in selected samples ranged from 19 to 76 mg kg^‐1. The excellent recoveries of the spike (98.5–101%) indicate that the proposed procedure is effective and feasible for the determination of total B in soils.