Determination of gentamicin in bovine milk using liquid chromatography with post-column derivatization and fluorescence detection |
| |
Authors: | Philip James Kijak Jean Jackson Badar Shaikh |
| |
Affiliation: | Food and Drug Administration, Center for Veterinary Medicine, Building 328-A, BARC-East, Beltsville, MD 20705, USA |
| |
Abstract: | A method capable of separating and quantifying the three major and one minor components of gentamicin in milk has been developed. The method is capable of detecting 15 ng/ml gentamicin, based on a total of the four components. Milk samples are centrifuged at 4°C, the fat layer removed, and the samples deproteinated with 30% trichloracetic acid. After a second centrifugation, the supernatant is passed through a C18 solid-phase extraction column. The column is washed with water, water-methanol (50:50) and methanol. Ammonium hydroxide (16%) in methanol is used to elute the gentamicin. The eluent is evaporated to near dryness and taken up with water. An aliquot of the sample is then mixed with an ion-pairing reagent for chromatography. Separation is achieved using pentanesulfonic acid in a water-methanol mobile phase on a C18 reversed-phase column. The o-phthalaldehyde fluorescence derivatives of gentamicin are formed post-column and are detected with excitation at 340 nm and emission at 430 nm. The percent recovery of gentamicin averaged 72, 78 and 88% from milk samples fortified at 15, 30 and 60 ng/ml, respectively. |
| |
Keywords: | Gentamicin |
本文献已被 ScienceDirect 等数据库收录! |
|