Separation and Analysis of Boron and Its Isotopic Composition in Plants
A method was developed to extract and concentrate boron in the plants( Echinacea Purpurea and Weigela Florida CV. Red Prince) by dry ashing coupled with two-step ion exchange chromatography. Boron isotope was subsequently analyzed by positive thermal ionization mass spectrometry. By the method,the effect of organic impurities on the determination can be eliminated and the boron can be recovered completely. The results showed the composition of boron isotope in the two plants ranged from !19.45‰ to +5.73‰ with the average of !2. 80‰,which indicated that a significant fractionation of boron isotope composition in the different tissues of the plants occurs.10B was enriched in stems in the two plants,which resulted in defect of11 B,but11B was enriched in flower and leaf relatively. This may be resulted in not only by the transpiration,but the biological effects of boron acid being bound to hydroxyl-rich organic molecules like sugars in the growth of plant,which puts forward a new method for the further investigation of boron behavior within plants and soil, and the global cycling of boron in the biogeochemistry.