Boron isotope ratios in commercial produce and boron-10 foliar and hydroponic enriched plants

Boron isotope ratios (11B/10B) for commercial produce ranged from a high of 4.162 +/- 0.003 for cabbage to a low of 4.013 +/- 0.008 for whole wheat flour. The observed isotope ratios for produce fall within the range reported for boron-containing minerals. Cucumbers and flour are 10B enriched; bananas, cabbage, celery, grapes, green peppers, lettuce, oranges, potatoes, and tomatoes are 11B enriched by at least 0.02; apples, broccoli, cantaloupe, and carrots are equal to NIST SRM-951 boric acid isotopic standard. Boron isotope ratios (11B/10B) were measured for broccoli and cabbage grown in a soilless medium, 4.018 +/- 0.016 and 4.032 +/- 0.003, in a soilless medium with foliar-applied H3 1OBO3, 1.848 +/- 0.009 and 1.746+/- 0.004, and in a hydroponic solution with H3 1OBO3 as the only boron source, 0.126 +/- 0.012 and 0.098 +/- 0.005