Electron-capture-gas chromatographic determination of atenolol in plasma and urine, using a simplified procedure with improved selectivity.

A sensitive gas chromatographic method for the quantitative analysis of atenolol in human plasma and urine is described. Atenolol is extracted with dichloromethane containing heptafluorobutanol to improve the extraction ability. Derivatization with trifluoroacetic anhydride in diethyl ether gives a bistrifluoroacetyl derivative which is more selectively detected by an electron-capture detector than is the corresponding heptafluorobutyryl derivative. The method allows determination down to 20 nmol/l (5 ng/ml) in 1 ml of sample with a relative standard deviation below 10%.