Sweeping technique combined with micellar electrokinetic chromatography for the simultaneous determination of flunitrazepam and its major metabolites.
A sweeping technique, in conjunction with micellar electrokinetic chromatography, for the simultaneous determination of flunitrazepam and its major metabolites, 7-aminoflunitrazepam and N-desmethylflunitrazepam, is described. The optimized conditions for the sweeping and separation were a pH 9.5 buffer, 25mM borate, 50mM cetyltrimethylammonium bromide, 30% MeOH (v/v), and a 151-mm injection length. The calibration functions were all linear with the coefficient of determination (r(2)) exceeding 0.996 for the three target compounds. Using the sweeping procedure, the limits of detection were determined to be 13.4, 5.6, and 12.0ng/mL for flunitrazepam, 7-aminoflunitrazepam, and N-desmethylflunitrazepam, respectively, and the sensitivity enhancement for each compound was within the range of 110-200 fold. The RSDs for the retention time and the peak area were less than 4.10%. The optimized sweeping method was also used to examine a spiked urine sample. We conclude that sweeping with micellar electrokinetic chromatography has considerable potential use in clinical and forensic analyses of flunitrazepam and its metabolites.
Department of Applied Chemistry, National Chiao Tung University, Hsinchu, Taiwan.
Chiung-Wei
CW
Huang
Hsiu-Ping
HP
Jen
Ren-De
RD
Wang
You-Zung
YZ
Hsieh
D014151:Anti-Anxiety Agents / Q000032:analysis; D002021:Buffers; D002138:Calibration; D000077286:Cetrimonium; D002593:Cetrimonium Compounds; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods*; D005445:Flunitrazepam / Q000031:analogs & derivatives* / Q000032:analysis*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D014151:Anti-Anxiety Agents; D002021:Buffers; D002593:Cetrimonium Compounds; C069164:N-desmethylflunitrazepam; D005445:Flunitrazepam; C036343:7-aminoflunitrazepam; D000077286:Cetrimonium