โ Scribed by N. Daoud; T. Arvidsson; K.-G. Wahlund
No coin nor oath required. For personal study only.
A liquid chromatographic method for determination of theophylline by direct injection of untreated plasma samples is described. Theophylline is detected without interference from related compounds such as paraxanthine.
A precolumn venting technique is used which considerably increases column life. The lifetimes of the separation columns are unaffected by plasma injections whereas the precolumn has to be changed after 140 injections (10 ~1 of plasma).
The peak purity of theophylline is examined spectrophotometrically. Determinations are performed by external standardization with recoveries close to 100% with a precision better than 2.3% (RSD).
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