Development and Validation of a Method to Determine the Boron Isotopic Composition of Crop Plants

摘要

We present a comprehensive chemical and massnspectrometric method to determine boron isotopic composi-ntions of plant tissue. The method including dry ashing, a three-nstep ion chromatographic boronu0001matrix separation, andn11nB/10nB isotope ratio determinations using the Cs2BO2nþngraphite technique has been validated using certified referencenand quality control materials. The developed method is capablento determine δ11nB values in plant tissue down to boronnconcentrations of 1 mg/kg with an expanded uncertainty ofne1.7% (k = 2). The determined δ11nB values reveal an enor-nmous isotopic range of boron in plant tissues covering three-nquarters of the natural terrestrial occurring variation in thenboron isotopic composition. As the local environment and anthropogenic activity mainly control the boron intake of plants, thenboron isotopic composition of plants can be used for food provenance studies.