Liquid chromatographic determination of diminazene diaceturate (Berenil) in raw bovine milk.
A simple liquid chromatographic (LC) method is presented for the determination of diminazene (DZ) in raw bovine milk. DZ is extracted from raw milk by chilled aqueous centrifugation and is isolated from milk components on a cyano solid-phase extraction column. DZ is eluted by using a methanol-ion pairing reagent. A Phenomenex LUNA CN column and an acetonitrile-buffered mobile phase with a counter ion are used for gradient LC. The LC effluent is monitored at a detection wavelength of 372 nm by using a deuterium lamp. Under the parameters described, the retention time of DZ is 8-10 min with a peak area response of 6.5 mAU/ng. The method demonstrated excellent precision over all levels tested (25-400 ppb) with an overall average recovery of 90.4 +/- 14.5%. The method is applicable to the monitoring of milk for DZ residues at the 25 ppb level with a limit of quantitation of 10 ppb.
Roybal
José E
JE
U.S. Food and Drug Administration, Animal Drugs Research Center, Denver Federal Center, PO Box 25087, Denver, CO 80225-0087, USA. jroybal@ora.fda.gov
Pfenning
Allen P
AP
Storey
Joseph M
JM
Gonzales
Steve A
SA
Turnipseed
Sherri B
SB
D000818:Animals; D000981:Antiprotozoal Agents / Q000032:analysis*; D002417:Cattle; D002498:Centrifugation; D002853:Chromatography, Liquid / Q000379:methods*; D003080:Cold Temperature; D003903:Deuterium; D004133:Diminazene / Q000031:analogs & derivatives* / Q000032:analysis*; D004350:Drug Residues / Q000032:analysis*; D007202:Indicators and Reagents; D008892:Milk / Q000737:chemistry*; D012680:Sensitivity and Specificity
D000981:Antiprotozoal Agents; D007202:Indicators and Reagents; D003903:Deuterium; C003915:diminazene aceturate; D004133:Diminazene