Fig. 1. Sectional view of electrode structure. (a) Conventional structure; (b) conical structure

Fig. 2. Ion trajectory (a) and electric field distribution (b) of the traditional drift tube and ion trajectory (c) and electric field distribution (d) of a new conical funnel drift tube

Fig. 3. Variation of the purity of limonene product ions with voltage under the two structures. (a) Traditional drift tube; (b) conical funnel drift tube

Fig. 4. Optimization of detection voltage for 8 substances under the two structures. (a) Traditional drift tube; (b) conical funnel drift tube

Fig. 5. Standard curves of 8 tested substances under the two structures. (a) Traditional drift tube; (b) conical funnel drift tube