(19)

(11)

EP 0 432 200 A1

(12)

(43) Date of publication: 19.06.1991 Bulletin 1991/25 (21) Application number: 89909940.0 (22) Date of filing: 31.08.1989

(51) International Patent Classification (IPC):  A01N 25/ 26( . ) A01N 47/ 36( . ) (86) International application number: PCT/US1989/003713 (87) International publication number: WO 1990/002486 (22.03.1990 Gazette 1990/07)

(84) Designated Contracting States: AT BE CH DE FR GB IT LI LU NL SE (30) Priority: 02.09.1988 US 19880240896 (71) Applicant: E.I. DU PONT DE NEMOURS AND COMPANY Wilmington Delaware 19898 (US)	(72) Inventor: TOCKER, Stanley Wilmington, DE 19803 (US) (74) Representative: Hildyard, Edward Martin, et al  Frank B. Dehn & Co. European Patent Attorneys Imperial House 15-19 Kingsway London WC2B 6UZ London WC2B 6UZ (GB)