[Fast and accurate method for theophylline analysis in preterm babies using gas chromatography and nitrogen selective...

The combined utilization of (a) a weak polar OV-1 phase, (b) an on-column methylation using a methylating agent commercially available, (c) a nitrogen selective detector (NFID) and (d) a small volume of sample, allows the development of a fast (less than 20 min) and accurate method for theophylline analysis in preterm babies. With 50 microliter of capillary whole blood sample, its limit of sensitivity was 0.5 microgram/ml of theophylline. This method is most desirable for theophylline monitoring in treating apnea of premature infants.