Data Views Exclude Ubiquitous Chemicals Activities: 348 Chemicals w/Activities: 37 All Chemicals: 61 CSV Excel PDF Previous1234 Show all rows. Paginate rows. Click on column headings to sort table by that column # Activity Chemical Part All Leaf Plant Root Low PPM High PPM StdDev *Reference 77 77 ZINC Root 15.0 51.0 1.17 * *Unless otherwise noted all references are to Duke, James A. 1992. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, FL. CRC Press.