title: Determination of gentamycin by synchronous derivative fluorimetry.
abstract: Use of synchronous first-derivative fluorimetry for determination of gentamycin is described. Gentamycin reacts with acetylacetone and formaldehyde in pH 5.6 HOAc/NaOAc buffer solution to form N-gentamyl-2,6-dimethyl-3,5-diacethyl-1,4-dihydropyridine[I] which is a fluorescent substance. Spectra of [I] and the reagent blank can be separated with synchronous derivative fluorimetry, and gentamycin can be determined directly. The synchronous spectral peaks of [I] and the reagent blank are at 434 and 411 nm, respectively. The first-derivative peak of [I] is at 425 nm. Effects of pH, foreign ions, buffer system, and heating time on the determination of gentamycin have been examined. The linear regression equation of the calibration graph is C=0.0513H-0.0416, with a correlation coefficient of linear regression of 0.9978. C means total potency of gentamycin: U ml(-1); H means peak height in the linear regression equation calibration graph. The linear range for the determination of gentamycin is from 0.00 to 3.00 U ml(-1). Recovery is from 95.06 to 112.0%, R.S.D. of 3.8%. The results determined by the fluorimetric method agreed roughly with those by the microbiological method. The method is simple and has low detection limit.
authors.affiliation: Department of Chemistry, Shandong Normal University, Jinan 250014, People's Republic of China.
authors.forename: H Y
authors.initials: HY
authors.lastname: Wang
authors.forename: L D
authors.initials: LD
authors.lastname: Liu
authors.forename: Y
authors.initials: Y
authors.lastname: Sun
authors.forename: L
authors.initials: L
authors.lastname: Ma
authors.forename: J
authors.initials: J
authors.lastname: Li