Routine identification and determination of 11 barbiturates in biological samples

Quantitative analysis of common anaesthetic agents

A summary of chromatographic (e.g. gas chromatography, high-performance liquid chromatography) and non-chromatographic (e.g. radioimmunoassay, enzyme-multiplied immunoassay) analytical techniques suitable for the quantitative analysis of the most popular inhalational (halothane, methoxyflurane, enflurane, isoflurane and nitrous oxide), intravenous (barbiturate, benzodiazepines, etomidate, althesin, morphine, fentanyl, alfentanil, sufentanil, droperidol and ketamine) general and amide-type local (lidocaine, mepivacaine, etidocaine and bupivacaine) anaesthetic agents and some of their metabolites, in biological material, is described. In the case of inhalational anaesthetics attention is also payed to pollution measurement and breath-to-breath monitoring.

Drug level monitoring: sedative hypnotics

Barbiturates and other traditional non-barbiturate sedative hypnotics are still extensively prescribed for the treatment of insomnia. There are a number of situations where identification or quantitative determination of these agents in biological fluids is required. Gas-chromatography offers highly sensitive and specific procedures for the determination of these compounds. The use of a nitrogen-specific detector allows a relatively simple sample preparation for sensitive detection and the use of capillary columns with bonded liquid phase allows separation of barbiturates without derivatization. In recent years liquid chromatography has also been extensively applied to the determination of these compounds. Sensitivity and selectivity of detection of barbiturates have been improved with the use of an alkaline mobile phase. Immunoassays for the determination of therapeutic concentrations of phenobarbital are very popular as the assays can be rapidly performed automatically. Use of these techniques has been extended for emergency detection of barbiturate overdose and for monitoring high-dose pentobarbital therapy.

Derivatization reactions in the gas—liquid chromatographic analysis of drugs in biological fluids

Alkylation, acylation, silylation and other derivatization reactions applied to the gas chromatographic analysis of drugs in biological matrices are reviewed. Reaction conditions are discussed in relation to reaction mechanisms. Detector-oriented labelling of drugs, and derivatization with chiral reagents for the separation of enantiomers are surveyed. Data on the sample clean-up, derivatization and GLC analysis of more than 300 drugs and related compounds are listed.

Analysis of barbiturates by gas chromatography

This review surveys the evolution of gas chromatographic procedures for the quantification of barbiturates as either the free acids or their derivatives obtained by direct and on-column reactions. Among the aspects discussed, some emphasis is placed on recognized and other sources of interference encountered during analyses.