(19)

(11)

EP 0 527 900 A1

(12)

(43) Date of publication: 24.02.1993 Bulletin 1993/08 (21) Application number: 91909769.0 (22) Date of filing: 29.04.1991

(51) International Patent Classification (IPC):  D21C 7/ 12( . ) G01N 33/ 34( . ) G01N 1/ 00( . ) (86) International application number: PCT/US1991/002933 (87) International publication number: WO 1991/017305 (14.11.1991 Gazette 1991/26)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 01.05.1990 US 19900517216 (71) Applicant: AUBURN UNIVERSITY Auburn, AL 36849 (US)	(72) Inventors: PAULONIS, Michael, A. 2601 John B. Dennis Highway Kingsport, TN 37660 (US) MONDAL, Debasish 4501 Sheraton Drive Macon, GA 31210 (US) KRISHNAGOPALAN, Aravamuthan Auburn, AL 36830 (US) (74) Representative: Baverstock, Michael George Douglas, et al  BOULT, WADE & TENNANT 27 Furnival Street London, EC4A 1PQ London, EC4A 1PQ (GB)