Rapid GLC Research Articles

Simultaneous determination of soluble sugars and organic acids as their trimethylsilyl derivatives in apricot fruits by gas-liquid chromatography

The aim of this study was to determine a reliable procedure for the quantification of organic acids, alcohol soluble sugars and sugar alcohols in fruit fresh by means of a rapid GLC method, without resorting to methoximation of sugars and employing apricot as a model. The use of two internal standards, an accurate derivatization and a proper calibration of the GLC conditions allowed an accurate quantitative analysis of the compounds detected in the unknown samples. This simple procedure improves the speed of preparation of the trimethylsilyl derivatives and is highly reproducible. Variability was found between years for each of the five cultivars studied and for each compound in terms of absolute values, whereas the percentage incidence of the single sugars as a total was more stable over the two years of observation.

Simple and rapid GLC method for the determination of orphenadrine in human plasma.

A rapid and specific method has been developed for the determination of orphenadrine concentration in plasma. It involves a one-step sample preparation using n-hexane/isopropyl alcohol (98:2) extraction, and analysis by gas chromatography on a wide bore capillary column using nitrogen/phosphorus detection. This procedure considerably simplifies previously reported assays and is specific and sensitive enough for the determination of orphenadrine in plasma of patients on chronic therapy.

Rapid and Simple GLC Determination of Valproic Acid and Ethosuximide in Plasma of Epileptic Patients

A GLC method for the determination of valproic acid and ethosuximide in plasma was developed. The procedure involved a single solvent extraction of drugs from acidified plasma samples, followed by a GLC injection of the unconcentrated organic phase. This rapid, sensitive, specific, and reproducible method has been used for 2 years for the routine determination of plasma levels of valproic acid and ethosuximide in epileptic patients who receive other antiepileptic drugs simultaneously.

Quantitative determination of conjugated estrogens in formulations by capillary GLC

A rapid capillary GLC method for the analysis of conjugated estrogen tablets and injectable formulations is described. The method involves the hydrolytic cleavage of the sodium sulfate ester conjugates by sulfatase enzyme. The free phenolic steroids are reacted sequentially with hydroxylamine hydrochloride and N, O-bis(trimethylsilyl)trifluoroacetamide. The resulting dual derivatives are analyzed on a 15-m glass capillary column wall coated with a cyanopropylmethyl silicone phase.

GLC assay of khellin in human serum and urine

A sensitive, specific and rapid GLC assay for khellin in serum and urine has been developed using flame ionization The method involves the addition of hyoscine as an internal standard, extraction with chloroform and the use of a 3% OV-17 on Gas Chromosorb column. The suitability of this procedure for serum sample analysis from rats after oral administration of the drug is reported.

A rapid gas liquid chromatography method for simultaneous determination of various anticonvulsants.

The purpose of this study was to develop a rapid GLC method for the simultaneous determination of the following anticonvulsants: Carbamazepine, Diphenylhydantoin, Phenobarbital, and Primidone. Using a metal column (OV-17) with flash heater methylation as well as high N2 flow-rate, a quantitative methylation of the above anticonvulsants was obtained. A selective temperature program proved to be the decisive factor in separating the various methylated anticonvulsants. The GLC program was completed within 13 min. This method permits a rapid, simultanous and quantitative determination of various important anticonvulsants.

GLC Determination of Trihexyphenidyl Hydrochloride Dosage Forms

A rapid, sensitive, and specific GLC method for the quantitation of trihexyphenidyl hydrochloride in various pharmaceutical dosage forms is described. The procedure involves chloroform extraction of the active ingredient from a weakly acidic solution, followed by GLC determination using a 3% methyl silicone column. The specificity of the system in relation to several compendial drug analogs also is reported.

Improved Electron-Capture GLC Determination of Alprenolol and Oxprenolol in Serum Using a Wall-Coated Open Tubular Column

An accurate, rapid, and sensitive GLC determination of alprenolol and oxprenolol in serum is described. This method combines an electron-capture detector with a wall-coated open tubular column. The lowest detectable amount of the halogenated (heptafluoroacyl) derivatives of alprenolol and oxprenolol is 2pg. The high resolving power and the rapid elution time of the wall-coated open tubular column dramatically improve the performance (accuracy and sensitivity) of the conventional electron-capture detector and packed column system in these determinations. This method allows the use of small volumes of sample (100–200μl), does not require redistilled reagents, and has a simplified extraction procedure.

Rapid Determination of Theophylline in Serum by Electron-Capture GLC

A rapid and sensitive GLC procedure was developed for the determination of theophylline in serum. After extraction from serum with ethyl acetate, theophylline and the internal standard were derivatized with pentafluorobenzyl bromide under alkaline conditions. The derivatives were quantitated by electron-capture detection. The method has a sensitivity of 0.1μg/ml with a 0.1-ml serum sample.

GLC Determination of Caffeine in Plasma Using Alkali Flame Detection

A rapid, specific, and sensitive GLC assay for caffeine in plasma was developed utilizing alkali flame-ionization detection. The procedure involves the addition of mepivacaine as an internal standard, alkalinization of the sample. and extraction with chloroform. Peak height ratio measurements produced linear standard curves in the 0.25-10.0-μg/ml range. Absolute sensitivity from a 1.0-ml plasma sample was 0.1μg/ml. The relative standard deviation of a 2.0-μg/ml pooled plasma standard run repeatedly over several months was 5.2%. The method is applicable to time-concentration studies in human and animal plasma following typical oral doses of caffeine.

Simplified GLC Assay for Lidocaine in Plasma

A simple, rapid GLC method for the determination of lidocaine in plasma is described. After addition of mepivacaine as an internal standard, the plasma sample is deproteinated and centrifuged. The supernate is alkalinized, and the lidocaine and internal standard are extracted into a microvolume of carbon disulfide. By using GLC with a flame-ionization detector, linear concentration-response curves were obtained in the 1–6-μg/ml range. The method can easily determine plasma concentrations at the 250-ng/ml level when a 1-ml plasma sample is analyzed.

GLC Determination of Lidocaine in Human Plasma

A specific, sensitive, rapid, and reproducible analytical GLC method for lidocaine in human plasma, including pharmacokinetic parameters, is described. Aminopyrine is the internal standard. The method was used to study pharmacokinetics in four healthy volunteers following the administration of a lidocaine bolus at a dose of 1 mg/kg iv and in one patient with cardiac arrhythmias who had been given a 50-mg bolus followed by a prolonged intravenous infusion for 30hr.

Rapid GLC Determination of Propranolol in Human Plasma Samples

A rapid GLC method for measuring plasma propranolol levels is reported. 4-Methylpropranolol was utilized as an internal standard. Pentafluoropropionate derivatives of propranolol and the internal standard eluted rapidly and gave good sensitivity under the conditions employed. The advantage of this procedure over previously reported methods is the speed of analysis, which is facilitated by rapid elution of contaminant peaks.

Simple GLC determination of ethylene oxide and its reaction products in drugs and formulations.

Convenient rapid GLC methods for the estimation of residual ethylene oxide, ethylene chlorohydrin, and ethylene glycol in ethylene oxide-sterilized bulk drugs and formulations prepared therefrom are described. Ethylene oxide was chromatographed using a porous polymer column; ethylene chlorohydrin and ethylene glycol were chromatographed using either polyethylene glycol 400 or a porous polymer column. All three residuals were determined from the same sample preparation for each type of drug or formulation examined. Recoveries of each of the three residuals were greater than 95% for all samples examined. Detection limits, at moderate electrometer sensitivities, were 2 microgram/g or ml for ethylene oxide and ethylene chlorohydrin and 5 microgram/g or ml for ethylene glycol. The most likely interferences are discussed.

Simultaneous GLC Determination of Acetaminophen, Dichloralantipyrine, and Isometheptene Mucate

A rapid GLC assay for acetaminophen, dichloralantipyrine, and isometheptene mucate in capsules was developed. These substances are chromatographed directly, using phenyl methyl silicone gum as the stationary phase. The standard calibration curves are linear up to 14mg/ml, with a lower limit of sensitivity of 2mg/ml. This method is simple and rapid and does not require derivative formation.

GLC analysis of lidocaine in plasma using a novel nitrogen-sensitive detector

AbstractA simple, rapid GLC method for the determination of therapeutic levels of lidocaine in plasma or blood is described. After extraction with benzene from alkalinized plasma, the compound is analyzed by GLC using a nitrogen-sensitive detector. Quantitation is accomplished using an internal standard and a standard curve, which was linear over the 0.1–10-μg range. The limit of detection was approximately 10 ng/ml. Recovery of the parent compound was essentially quantitative. Plasma data are presented to demonstrate the utility of the method.

Rapid GLC determination of fusaric acid in biological fluids.

A simple, sensitive GLC assay was developed for fusaric acid, the active metabolite of bupicomide, to follow the disposition of this investigational antihypertensive agent in patients undergoing therapy. Fusaric acid is efficiently extracted from biological samples, derivatized by on-column methylation, and chromatographed using flame-ionization detection. An internal standard is utilized to quantitate results. The procedure is rapid and specific for fusaric acid, and has a lower limit of sensitivity of 0.1 mug/ml. The method is suitable for supporting pharmacokinetic studies of bupicomide following therapeutic doses in animals and humans.

Bakkenolide-A. Its distribution in Petasites species and cytotoxic properties

A rapid GLC method is described for the determination of bakkenolide-A in small amounts of plant material. The distribution of bakkenolide-A among the different lipid classes of Petasites albus is discussed and also the distribution among different parts of the plant during a growing season. Smaller amounts of bakkenolide-A are found in P. hybridus buds and only trace amounts in P. fragrans. Cytotoxicity tests showed bakkenolide-A has marked cytotoxic activity and potential anti-tumour properties.

GLC Determination of Underivatized Carbamazepine in whole Blood

This report describes a rapid GLC assay for carbamazepine in blood. Carbamazepine is chromatographed directly using phenyl methyl silicone gum as the stationary phase. The calibration curve is linear up to 50 μg/ml, with a lower limit of sensitivity of 1 μg/ml, Other anticonvulsants may be measured simultaneously, and the procedure works equally well with plasma or blood.

GLC Determination of Hexadiphane in Pharmaceutical Preparations

AbstractA specific, rapid, and sensitive GLC method for purity control of hexadiphane and its determination in pharmaceutical preparations is described. The method utilizes an extraction of the free base, followed by GLC on a 0.5% OV-17 column at isothermal temperature for 6 min and then the temperature was programmed. Results from this method and from a titrimetric method were compared, and no significant differences were found.