Extrashot-ODS, a syringe-type minicolumn sample injector for a reversed-phase high-performance liquid chromatographic column. Application to antiepileptics in human sera.
Extrashot-ODS (EXS-ODS) is a syringe-type minicolumn developed for sample injection into reversed-phase high-performance liquid chromatographic columns. EXS-ODS consists of (a) a stainless-steel needle fitted to an ordinary syringe-loading sample injector for HPLC, (b) a 45-microl minicolumn tube made of polytetrafluoroethylene (PTFE) and packed with ODS-silica and (c) a minicolumn holder made of polystyrene, which is connected to the needle on one side and the other side is shaped so as to be fitted with a solvent syringe. Using the device, we simultaneously analyzed three antiepileptics in 20 microl of human sera. First, we introduced a 20-microl serum specimen diluted with 100 microl of buffer solution into the device and, second, 100 microl of distilled water. Then the device was attached to the HPLC injector and 130 microl of methanol were introduced into the HPLC column through the device. Then, reversed-phase HPLC was conducted in the usual manner, with the chromatogram reading at a wavelength of 210 nm for the assays of 5,5-diphenylhydantoin, phenobarbital and carbamazepine. The results obtained by direct peak-height calibration were comparable to those given by the immunological method.
Kouno
Y
Y
Bohsei Pharmacy Co., Isehara, Kanagawa, Japan.
Ishikura
C
C
Homma
M
M
Oka
K
K
D000927:Anticonvulsants / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use; D002220:Carbamazepine / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation*; D004359:Drug Therapy, Combination; D004827:Epilepsy / Q000097:blood / Q000188:drug therapy; D006801:Humans; D007124:Immunoenzyme Techniques; D010634:Phenobarbital / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use; D010672:Phenytoin / Q000008:administration & dosage / Q000097:blood / Q000627:therapeutic use
D000927:Anticonvulsants; D002220:Carbamazepine; D010672:Phenytoin; D010634:Phenobarbital