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Biomedical subjects

R H Hertel

Publications and source records attributed to R H Hertel.

2 recordsLinked to original sources

A microcomputer-directed mass spectrometer as a compound-selective detector for gas chromatography.

Determination and quantitation by mass spectrometry can be difficult for compounds in complex biological mixtures where chromatographic interferences are frequently encountered. A gas chromatographic-mass spectrometric system is described which utilizes reverse spectral search and retention time screening to provide a high degree of compound specificity. Computer control of instrument operation, and of data acquisition, analysis and printout allows technologist operators to obtain highly reliable, precise quantitative results using relatively crude sample preparation procedures and short chromatographic times.

Anticonvulsants↗

Gas-chromatographic/mass-spectrometric determination of theophylline in whole blood.

We describe a combined gas-chromatographic mass-spectrometric method for determination of theophylline in whole blood. With use of a probability-based matching approach, the extensive gas-chromatographic interference did not affect mass-spectrometric quantitation of theophylline. Concentrations expected and found were linearly related from 1 to 60 mg/liter; the run-to-run coefficient of variation was less than 8%, within-run less than 6%. Some other xan-thines and drugs frequently co-administered with theophylline did not affect results. Only 0.2 ml of blood is required, which makes the procedure useful for monitoring theophylline in newborns and pediatric populations.

Chromatography, Gas↗