Sensitive method for the determination of the antiarrhythmic drug detajmium in serum by solid-phase extraction and high-performance liquid chromatography with fluorimetric detection

The objective of this study was to develop a very sensitive and selective m ethod for the determination of detajmium (4-3-diethylamino-2-hydroxypropyl- ajmaline) a sodium-channel-blocking drug with antiarrhythmic propel-ties, i n serum. A high-performance liquid chromatography (HPLC) method with solid- phase extraction and fluorimetric detection has been applied. Serum samples were diluted with phosphate buffer (pH 3.5) and the extraction of detajmiu m and ajmaline, which was used as an internal standard, was carried out wit h Oasis cartridges (Waters). The chromatographic separation was performed o n a RP18 column. The limit of quantification for serum samples of detajmium was 1 ng/ml with good reproducibility (R.S.D.<15%) and a linear response f rom 1 to 200 ng/ml. The described method is highly sensitive and specific f or the determination of detajmium in serum of patients and volunteers. (C) 1999 Elsevier Science B.V. All rights reserved.