Mj. Llobatestelles et al., SPECTROPHOTOMETRIC DETERMINATION OF THE THEOPHYLLINE IN PLASMA BY THEAPPARENT CONTENT CURVES METHOD, Talanta, 43(9), 1996, pp. 1589-1594
A direct spectrophotometric procedure for the determination of theophy
lline in plasma is proposed. This procedure is based on the apparent c
ontent curves method and it is not necessary to know the nature and co
ntents of interferent substances. Bias errors introduced by plasma and
metabolites are avoided. The results obtained are in agreement with t
hose provided by an immunofluoroassay used as a reference method.