A VUV Photoionization Aerosol Time-of-Flight Mass Spectrometer with a RF-Powered VUV Lamp for Laboratory-Based Organic Aerosol Measurements

Figures & data

FIG. 1 Schematic diagram of the ion optics. The VUV photoionization region shown in Figure 1 is schematic.

FIG. 2 Mass spectra of oleic acid and cholesterol particles. The particles were vaporized at 402 K. Figure 2a and Figure 2b show the mass spectrum of oleic acid and cholesterol particles, respectively. The zoomed plot in Figure 2a presents a detail of the mass spectrum of oleic acid around m/z = 282. Each spectrum was collected in 30 s. The mass concentrations of the oleic acid and cholesterol particles produced are 196 mg/m³ and 220 mg/m³, respectively.

FIG. 3 Dependence of the signal intensity on the mass concentration of oleic acid particles. The signal intensities are calculated by accumulating the total counts in the range of mass 280 ± 0.5 (see Figure 2a). The black squares are data points and the line is the result of a linear fit.

TABLE 1 Experimental data examining the dependence of the signal intensity on the mass concentration of oleic acid particles

C(mg/m^3)*	3.9	9.8	19.6	49	98	196	392
S(counts)	135	283	581	1408	2800	6816	10916
SD	± 6	± 18	± 44	± 95	± 128	± 157	± 172
B(counts)	49	66	114	134	242	453	967
Neat S	86	217	477	1274	2558	6363	9949