Assessment of Ground-Based and Aerial Cloud Seeding Using Trace Chemistry

Table 1

Operating ICP-MS conditions and acquisition parameters.

Parameter	Setting value
Forward power	1400 W
Cooling	13 L/min
Expansion pressure	2.0 10^0 mbar
Analyzer pressure	4.0–4.2 10^−7 mbar
Turbo pump speed	1000 Hz
Vacuum pump load	0.8–1.2 A
Pole bias	1.0
Hex bias	4.0
Sample cone	Ni, 1.1 mm aperture inner diameter
Microskimmer cone	Ni, 0.8 mm aperture inner diameter
Sample depth	Adjusted daily
Lens settings	Adjusted when appropriate
Nebulizer back pressure	~2.0 bar, optimized daily
Nebulizer Flow Rate	400 μL/min
Sample Uptake Time	20 s
Rinse Time between samples	20 s
Elements measured	Na, Al, Cr, Co, Sr, Ag, Ba, La, Ce, Pb
Dwell time per element	Ag: 200 ms; Na, Al, Cr, Co, Sr, Ba, La, Ce, Pb: 10 ms

Optimized to obtain a stable/high 115 In signal (>500,000 cps for 10 ppb) min. oxide formation rate.