Ejg. Portier et al., Simultaneous determination of fentanyl and midazolam using high-performance liquid chromatography with ultraviolet detection, J CHROMAT B, 723(1-2), 1999, pp. 313-318
When measuring fentanyl and midazolam simultaneously in the same plasma sam
ple with standard high-performance liquid chromatography-ultraviolet (HPLC-
UV) detection, overlap of the fentanyl peak by the midazolam peak occurs, w
hich makes fentanyl determination impossible. We tested the hypothesis that
by acidifying the methanol mobile phase with 0.02% perchloric acid, 70%, i
t would be possible to separate both peaks. The UV detector was set at 200
nm. Calibration curves for fentanyl (range 0-2000 pg/ml) and midazolam (ran
ge 0-400 ng/ml) were linear (r>0.99). The detection limits were 200 pg/ml (
fentanyl) and 10 ng/ml (midazolam). Precision and accuracy for intra- and i
nter-assay variability as well as in-line validation with quality control s
amples (QCS) were acceptable (< 15 and 20%, respectively), except for fenta
nyl QCS of 200 pg/ml (17.8% precision). Although less sensitive than gas ch
romatography-mass spectrometry (GC-MS), reliable measurements of fentanyl,
simultaneously with midazolam, can be performed with this HPLC-UV system. (
C) 1999 Elsevier Science B.V. All rights reserved.