A gas chromatographic method for the analysis of nine organochlorine pesticides in wildlife urine is described. Reversed-phase solid-phase extraction is utilized to extract the organochlorine pesticides from urine. The pesticides are recovered by elution with hexane-ethyl ether (1:1) and quantified by gas chromatography with electron-capture detection. Method detection limits range from 1.4 to ...

A quantitative gas liquid chromatographic method for the determination of serum levels of perazine (10-[3'-(1''-methyl-4''-piperazinyl)-propyl]-phenothiazine) is described. Perazine is used as a neuroleptic drug. The main problem consists in optimizing the chromatographic system. A sensitivity of appr. 60--150 nmol/1 (20--50 microgram/1) serum is achieved. Examples of optimization, analyses wit...

We describe a sensitive, precise high-pressure liquid chromatographic method in which 5-(p-methylphenyl)-5-phenylhydantoin is used as the internal standard for simultaneous determination of diphenylhydantoin, phenobarbital, and primidone in whole blood and plasma. These anticonvulsant drugs are well separated from each other and from normal blood constituents in less than 10 min. The lower limi...

We present a simple, new clean-up method for the gas-chromatographic profiling analysis of acylcarnitines. The use of a solid-phase, cation-exchange extraction combined with gas-chromatographic separation, based on the derivatization into acyloxylactones by Lowes and Rose (Analyst 1990;115:511-6), allows a selective and sensitive screening for acylcarnitines in urine. As such, a quantitative ap...

We describe a sensitive and precise gas-chromatographic method, in which cytosine is used as the internal standard, for determination of an antifungal agent, 5-fluorocytosine, in serum. The trimethylsilyl derivative of this drug is well separated from the internal standard and from normal serum constituents. Amphotericin B does not interfere with the determination of 5-fluorocytosine. The lower...

It is of great practical importance to develop simple methods for the automatic detection ofthe controlled state of the analytical method being applied. The key point is to find quantities that greatly affect the quality of the analytical results and that can be easily estimated during the measurement process from the measured data. The signal-to-noise ratio has proved to be such a quantity in ...

L-Carnitine is used extensively in functional foods and food supplements; consequently, the control of its enantiomeric purity is of paramount importance. A new derivatization procedure and chiral gas chromatographic method with flame ionization detection, using a cyclodextrin based stationary phase, enables prompt, simple, and inexpensive screening of the enantiomeric ratio of L- and D-carniti...