Doping control for beta-adrenergic compounds through hair analysis

An original procedure was developed to simultaneously test beta(2)-agonists (salbutamol and clenbuterol) and beta-blockers (atenolol, acebutolol, pind olol, betaxolol, propranolol, timolol, sotalol, metoprolol, tertatolol, bis oprolol, labetalol and oxprenolol) in both human and animal hair. After dec ontamination with methylene chloride (2 times, 2 min), a 200 mg hair strand is pulverized in a hall mill. Then, a 100 mg portion is incubated overnigh t in 2 mt 0.1 N HCl, at 56 degrees C, in the presence of carteolol, which w as used as an internal standard. After neutralization of the acid phase wit h 0.1 N NaOH, a 2 mt bicarbonate buffer (pH 8.6) is added to the preparatio n, which is then purified by solid-phase extraction with Isolute C18 column s. Drugs are derivatized using a mixture of trimethyl boroxine-ethyl acetat e for 15 min at 80 degrees C to form methaneboronate derivatives. Drugs are detected using GC/MS on an HP 6890-5973 system. A 4 mu L portion of the de rivatized extract is injected using a pulsed mode in a 30 mHP5 MS capillary column. Linearity was observed for all compounds in the range 25 pg/mg to 10 ng/mg. Limits of detection were in the range 2 to 10 pg/mg. At I ng/mg, recoveries were in the range from 37 to 100%, with a within-run precision o f 5.9 to 14.1% (n = 8). The application of the method can be documented by the following examples: (I) Hair from asthmatic patients (n = 11), including two cases of asthma de aths, tested positive for salbutamol in the range of 23 to 210 pg/mg. (2) A 24-year-old swimmer who tested positive in urine for salbutamol denied the results. Hair analysis confirmed salbutamol exposure, with a concentration of 71 pg/mg. (3) A shooting specialist was assumed to chronically use meto prolol (100 mg/daily, during some periods). Hair concentration of metoprolo l was 8.41 ng/mg. (4) An archery specialist was assumed to chronically use sotalol (80 mg/daily, during some periods). Hair concentration of sotalol w as 261 pg/mg. (5) Hair from two calves revealed chronic exposure to clenbut erol, which was used to increase the mass of the animals at a concentration of 30 and 48 pg/mg.