Figure 3: Mass spectra of the test sample (p-chloroamphetamine; concentration level, 0.1 μg/mL) obtained for the regular triangle chromatography paper-spray procedure and beveled end hollow fiber-spray mass spectrometry, respectively. Frame A, mass spectrum obtained by the regular method, i.e., use of a triangular shaped chromatography paper; Frame B, a microextraction was performed and the data obtained by the beveled end hollow fiber method.