Document N24jO4aVGK30yK015BMXn8OOD

INSTITUUT VOOR . VETERINAIRE FARMACOlOGl ) ' EN TOXICOLOGIE * DER RIJKSUNIVERSITEIT TE UTRECHT DIRECTEUR: Prol. H. VAN GENDEREN No. BorlcHf cP' Bolrolkndi: Bijkgon: o UTRECHT, March 13, 1969 Blllitrul 172 Tskfoon No. 715544 Monsanto Chemioale Ltd, 800 North Lindheigi Boulevard, ST.LOUIS (Missouri) USA Bear Sir, In June last year you kindly supplied us on our request with a number of Aroolor samples. Particularly Aroolor.1260 proved to have a peak pattern which strongly resembles the pattern observed in gas chromatograms of extracts from tissues of Bea birds living along the Netherlands' ooast. This qualitative resemblanoe was further confirmed by using a gas chromatograph in conjunction with a mass spectrometer. A paper oonoerning the qualitative composition of similar residues in fish in' the river Rhine and birds in the Vadden Sea area has been ac cepted for publication by ''Nature" and we will send you a reprint as soon as they are available. Ibe quantitative evaluation of the residues was carried out by peak height comparison using one of the prevalent peaks in the gas chro matograms. In due oourse we will be able to check this procedure by com parison with quantitative measurements carried out with a microcoulometric detection system. He would like to go further and identify the isomers. Hith the method used at the moment residue levels in sea bird tissues range up to 150 ppm. In the laboratory we have tested a PCB-mixture in a semiohronio toxioity assay with Japanese quails. Tissues residues in quail which died during this test were muoh higher than those found in birds which died in our coastal areas. Still, we would like to extend our toxioologioal information in order to try to establish a "no-offect-level" in 8emi-ohronio (three months) tests for at least some of the different compounds present in the wild birds' tissues. ' We would be glad to know if your ooepany might have available for our purpose some members of the PC3 as pure compounds with known position of the ohlorine atoms, Ve are particularly interested in those w'ith 4 up to 8 ohlorine atoms. For the identification in g.l.c. analysis about 100 mg of each compound would be enough. For tho toxicological tests (with Japanese quails), if possible supplemented with rats, a minimum of 10 g is needed. He hope that you may help us and we look forward to your reply. DSM 019664 Sincerely yours, H. van Genderen. Professor of Veterinary Pharmacology and Toxioology, University of Utreoht,' Biltstraat 172. Utrecht ( The Uetherl ands'l . STLCOPCB4007597