Determination of clenbuterol and mabuterol in equine plasma by ion-pair liquid chromatography with electrochemical detection. Chromatographic and electrochemical characteristics.
A method for the routine determination of the beta-adrenergic drugs clenbuterol and mabuterol in equine plasma has been developed. The drugs were isolated from alkalinized plasma by liquid-liquid extraction. The organic phase was evaporated to dryness and the residue was dissolved in the mobile phase prior to injection. The recoveries were 98% and 95% for clenbuterol and mabuterol, respectively. The drugs were separated by reversed-phase high-performance liquid chromatography and quantitated by a use of a coulometric detector set at +0.75 V vs. the internal reference electrode. The influence of pH and amounts of organic modifier and ion-pairing agent on the retention times was investigated. The relationship between peak current and concentration was linear up to 1 microgram/ml for both compounds. The limits of detection were 0.5 ng/ml for clenbuterol and 2 ng/ml for mabuterol with a signal-to-noise ratio of 3. A brief discussion of the electrochemistry of the compounds is given.
D000318:Adrenergic beta-Agonists / Q000097:blood*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D002976:Clenbuterol / Q000031:analogs & derivatives / Q000097:blood*; D004563:Electrochemistry; D004983:Ethanolamines / Q000097:blood*; D006736:Horses; D006863:Hydrogen-Ion Concentration
D000318:Adrenergic beta-Agonists; D004983:Ethanolamines; C044573:mabuterol; D002976:Clenbuterol