Capillary electrochromatographic analysis of barbiturates in serum

• Published in: Electrophoresis 2004-02, Vol.25 (4-5), p.594-599
• Main Authors: Ohyama, Kaname, Wada, Mitsuhiro, Lord, Gwyn A., Ohba, Yoshihito, Fujishita, Osamu, Nakashima, Kenichiro, Lim, Chang Kee, Kuroda, Naotaka
• Format: Article
• Language: English
• Subjects: 3‐(1,8‐Naphthalimido)propyl‐modified silyl silica gel; 8-Naphthalimido)propyl-modified silyl silica gel; Barbiturates; Barbiturates - blood; Barbiturates - isolation & purification; Buffers; Capillary electrochromatography; Chromatography, Micellar Electrokinetic Capillary - methods; Humans; Hydrogen-Ion Concentration; Methanol - chemistry; Reproducibility of Results; Silicon Dioxide - chemistry; Time
• ISSN: 0173-0835; 1522-2683
• DOI: 10.1002/elps.200305703

A capillary electrochromatographic method was developed for the separation of barbiturates. The separation was optimized in a 75 μm ID capillary, packed with 3‐(1,8‐naphthalimido)propyl‐modified silyl silica gel (NAIP), studying the effect of buffer pH, buffer concentration, 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 40% methanol provided the baseline separation of barbital, phenobarbital, secobarbital, and thiopental (internal standard) in less than 4.5 min. The method was successfully applied to the analysis of barbiturates in human serum. Under the optimal conditions, good repeatability and linearity were obtained in the range of 2.90–43.29 μg/mL for barbital, phenobarbital, and secobarbital.