The gas chromatographic determination of atenolol in biological samples

Methods are described for the gas chromatographic determination of the B-adrenoceptor blocking agent atenolol (ICI 66,082 Tenormin) in whole blood, serum, tissue and urine. The method involves the extraction of the free base from the prepared biological sample into an organic solvent mixture. Further purification is done by backextracting the base into dilute acid from which, after basification it is extracted again into organic solvent. Any atenolol in the residue remaining after solvent evaporation is converted into a heptafluorobutyrate derivative ready for gas chromatography. Use of an electron-capture detector enables concentrations as low as 0.01 mug ml-minus 1 body fluid and 0.04 mug ml-minus 1 tissue to be measured.