James W. Munson

Determination of N-Nitrosonornicotine in Tobacco by Gas Chromatography/Mass Spectroscopy

Abstract N-Nitrosonornicotine has been determined in tobacco products. Quantitation was accomplished by GC/MS operated in the chemical ionization mode with selected-ion recording of N-nitrosonornicotine and the deuterated internal standard, N-nitrosonornicotine-d4. Levels ranging from 0.7 to 26 mcg/gm were found.

Determination of theophylline in plasma by oxidation at the stationary carbon-paste electrode.

A method for the determination of the concentration of theophylline in plasma at therapeutic levels is described. The method is based on the oxidation of theophylline at the stationary carbon-paste electrode and involves a simple extraction procedure and differential pulse voltammetry. Possible interferences are discussed and typical calibration curves are presented.

A new spot test for aliphatic aldehydes and ketones

Abstract A new spot test for aliphatic aldehydes and ketones has been developed utilizing free-radical formation. Aliphatic aldehydes are detected in the range of 0.2–200 μg while aliphatic ketones are detected from 100–2000 μg. Benzaldehyde was the only other compound tested that gave a positive result.

HPLC Assay for Trimethoprim in Plasma and Urine

Abstract A sensitive HPLC method for the quantitation of trimethoprim in plasma and urine was developed using fluorescence detection. Plasma (or urine) samples were made basic by the addition of 3.8N sodium hydroxide and extracted with chloroform:2-propanol (95:5). After evaporation of the organic layer, a portion of the residue was analyzed by HPLC with fluorescence detection. The minimum detectable quantity is 0.1 μg/ml for this method. This method has been applied to the analysis of plasma and urine obtained from subjects after a single 160 mg dose of trimethoprim.