title: Determination of naltrexone and 6beta-naltrexol in human blood: comparison of high-performance liquid chromatography with spectrophotometric and tandem-mass-spectrometric detection.
abstract: We present data for a comparison of a liquid-chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) and a high-performance liquid-chromatographic method with column switching and UV spectrophotometric detection. The two methods were developed for determination of naltrexone and 6beta-naltrexol in blood serum or plasma aiming to be used for therapeutic drug monitoring to guide the treatment of patients with naltrexone. For the high-performance liquid chromatography (HPLC)/UV detection, online sample cleanup was conducted on Perfect Bond C(18) material with 2% (vol/vol) acetonitrile in deionized water. Drugs were separated on a C(18) column using 11.5% (vol/vol) acetonitrile and 0.4% (vol/vol) N,N,N,N-tetramethylethylenediamine within 20 min. LC-MS/MS used naltrexone-d (3) and 6beta-naltrexol-d (4) as internal standards. After protein precipitation, the chromatographic separation was performed on a C(18) column by applying a methanol gradient (5-100%, vol/vol) with 0.1% formic acid over 9.5 min. The HPLC/UV method was found to be linear for concentrations ranging from 2 to 100 ng/ml, with a regression correlation coefficient of r (2) > 0.998 for naltrexone and 6beta-naltrexol. The limit of quantification was 2 ng/ml for naltrexone and 6beta-naltrexol. For the LC-MS/MS method the calibration curves were linear (r(2) > 0.999) from 0.5 to 200 ng/ml for both substances, and the limit of quantification was 0.5 ng/ml. The concentrations measured by the two methods correlated significantly for both substances (r(2) > 0.967; p < 0.001). Both methods could be used for therapeutic drug monitoring. The HPLC/UV method was advantageous regarding automatization and costs, whereas LC-MS/MS was superior with regard to sensitivity.
authors: Department of Psychiatry and Psychotherapy, University of Mainz, Untere Zahlbacherstrasse 8, 55131, Mainz, Germany.
authors: Sonja
authors: S
authors: Brünen
authors: Ralf
authors: R
authors: Krüger
authors: Susann
authors: S
authors: Finger
authors: Felix
authors: F
authors: Korf
authors: Falk
authors: F
authors: Kiefer
authors: Klaus
authors: K
authors: Wiedemann
authors: Karl J
authors: KJ
authors: Lackner
authors: Christoph
authors: C
authors: Hiemke
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000191:economics / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000097:blood; D013053:Spectrophotometry / Q000191:economics / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000191:economics / Q000379:methods*
chemical_list: C010410:6 beta-hydroxynaltrexone; D009271:Naltrexone