A suitable MISF scanning route is essential for MISF measurements.
This trajectory was simply a MISF scanning route for the detection of coproporphyrin (indicated by the "i" in Fig.
Using the above selected trajectory, we recorded MISF spectra of porphyrins; the scanning time for a MISF spectrum is only ~20 s.
To test the validity of the proposed MISF method, we performed quantitative spectrophotometric and fluorimetric measurements of fecal porphyrins, as proposed by Lockwood et al.
2), whereas MISF spectroscopy provides a simple method to selectively detect a fluorescent compound in the presence of another strongly interfering one.
MISF spectra can be plotted in either the three-dimensional (Fig.
First-derivative MISF spectra for coproporphyrin and protoporphyrin added in various concentrations to 1.0 mol/L hydrochloric acid are shown in Fig.
We compared the proposed MISF method with conventional spectrophotometry (5) and fluorimetry (6).
Similarly, we compared the MISF method and conventional fluorimetry (Fig.
The absorbance, fluorescence excitation, and MISF spectra of a fecal specimen from a pregnant woman analyzed by these three methods are shown in Fig.
The derivative MISF signals of the samples were then measured.
MISF spectrometry is a useful technique for resolving mixtures with badly overlapping spectra.