Document 7ZnzKv2OmaGpXVye44y1R5ne

Mr. Robert Z. Rollins, Chief . Chemistry Laboratory Services California Department of Agriculture 1220 North Street . .. : Sacramento, California 95814 Dear Mr. Rollins: In reply to your recent letter, we have sent to your attention under separate cover, three bottles containing about 50 grams each of our Aroclor 1242, 1254 and 1260. These products are biphenyl chlorinated to the percentage level indicated bv the last two figures in each number. The samples are electrical ..grade materials, representative of our normal production. -We are aware of the work of Dr. Robert Risebrough at the ' University of California, Berkeley. V7e have an analytical :research program underway for the identification and measure ment of polychlorinated biphenyls in biological and plant . materials. This work is based on concentration schemes ' followed by gas chromatography procedures with final ' characterization by mass spectroscopy. To date, we have no. methods at a suitable state of development for release,1 For your information, we are also following work reported by Holmes, et al in Nature 216 227 (1967). To the best of our knowledge, Aroclors are not used as solvents in pesticide formulations. All of the Aroclors are practically insoluble in water. For example, Aroclor 1242 is soluble at 25C only to the extent of ' about 200 parts per billion; Aroclor 1248 100 pob and Aroclor . ! 1254 50 ppb. If we can be of any further assistance, please let me know. Sincerely, Robert E. Keller _ Manager of Applied Sciences - - -- db . . DSW 201038 STLCOPCB4059102