Fig. 3. The m /z 28, 29 and 30 traces during
analysis of Qz (left) and SWy-1 (right) with different inorganic
fluoride. (A, B) LiF, (C, D) NaF, (E, F) KF, (G, H)
BaF2, (J, K) CaF2, (L, M)
AlF3. The intensity of reference gas ofm /z 29 was set approximately 6000 mV for each measurement.
3.3. Influence of F/O molar ratio
(Run3)
Based on the results of Run2, the reactivity was investigated by varying
the F/O ratio using NaF as the fluorine source (Fig. 4). For both Qz and
SWy-1, increasing the F/O ratio from 2 to 6 gradually made the CO peak
shape more symmetrical, eliminating the tailing and plateau on the right
side and bringing the end positions earlier. This led to an improved
reproducibility of the end positions and areas of the CO peaks. In
contrast to SWy-1, Qz’s peak tended to end a little bit later. The
difference in reactivity between SWy-1 and Qz may have been influenced
by the former’s smaller grain size and the larger specific surface area.
It is expected that the measurement time per sample can be decreased to
approximately 20–30 min, owing to the shortened CO peaks.