Rapid separation of barbiturates and benzodiazepines by capillary electrochromatography with 3-(1,8-naphthalimido)propyl-modified silyl silica gel.
A capillary electrochromatographic (CEC) method was applied to the simultaneous separation of barbiturates (barbital, phenobarbital, secobarbital and thiopental) and benzodiazepines (nitrazepam, diazepam and triazolam). The separation was performed in a 75 microm i.d. capillary, packed with 3-(1,8-naphthalimido)propyl-modified silyl silica gel (NAIP), studying the effects of buffer pH and mobile phase composition. Using an applied voltage of 20 kV and the short-end injection method (9 cm capillary effective length), the mobile phase of 1.0 mM citrate buffer (pH 5.0) containing 45% methanol provided the baseline separation of seven toxic drugs in less than 9 min. In CEC with NAIP, the benzodiazepines were separated by the combination of hydrophobic and pi-pi interactions, whereas the separation of the barbiturates was based on the hydrophobic interaction.
Ohyama
Kaname
K
Graduate school of Biomedical Sciences, Course of Pharmaceutical Sciences, Nagasaki University, Nagasaki, Japan.
Wada
Mitsuhiro
M
Ohba
Yoshihito
Y
Fujishita
Osamu
O
Nakashima
Kenichiro
K
Kuroda
Naotaka
N
D001463:Barbiturates / Q000302:isolation & purification*; D001569:Benzodiazepines / Q000302:isolation & purification*; D002021:Buffers; D002853:Chromatography, Liquid / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009942:Organometallic Compounds / Q000737:chemistry*; D012997:Solvents
C498079:3-(1,8-naphthalimido)propyl-modified silica gel; D001463:Barbiturates; D002021:Buffers; D009942:Organometallic Compounds; D012997:Solvents; D001569:Benzodiazepines