Abstract: A simple method, second-order calibration coupled to three-dimensional excitation-emission fluorescence spectroscopy, was described for the direct determination of honokiol and magnolol in human plasma and complicated magnoliae officinalis. When the component number(N) was set to 3, the obtained recoveries of honokiol and magnolol in human plasma by using the parallel factor analysis(PARAFAC) were (99.5±2.6)% and (90.2±1.8)%, respectively. As the alternating trilinear decomposition(ATLD) was utilized, the recoveries of honokiol and magnolol were (104.2±3.2)% and (98.7±4.0)% for N=3, (102.7±2.9)% and (99.0 4.6)% for N=4, respectively. And the method was used to determine honokiol and magnolol in complex magnoliae officinalis, the obtained results were also satisfactory. It was shown that the proposed method can be used to determine directly honokiol and magnolol, even in the presence of unknown interferences, with a simple pretreatment procedure.

Key words: Honokiol, Magnolol, Plasma, Magnoliae officinalis, Excitation-emission fluorescence, Second-order calibration, Chemometrics