As you increase the liquid flow rate from the LC system, Thermo Fisher Scientific recommends that you increase the gas flow to the ion source and the temperature of the ion transfer tube heater and the vaporizer to avoid excess fluid buildup in the ion source housing.
The recommended starting settings for the spray voltage are independent of the LC flow rate:
- Positive polarity mode: 3500 V
- Negative polarity mode: 2500 V
The recommended starting temperature for the ion transfer tube heater depends on whether the mass spectrometer’s ion transfer tube has an elongated bore or a narrow bore.
LC Flow Rates (μL/min) | <=14.99 | 15–99.99 | 100–199.99 | 200–499.99 | 500–999.99 | 1000–3000 |
|---|---|---|---|---|---|---|
Sheath gas (arb) | 5 | 25 | 35 | 50 | 60 | 75 |
Aux gas (arb) | 2 | 5 | 7 | 10 | 15 | 25 |
Sweep gas (arb) | 0 | 0 | 0 | 1 | 2 | 2 |
Vaporizer temp (°C) | 20 | 75 | 275 | 350 | 350 | 400 |
Nitrogen consumption (L/min) | 3.5 | 8 | 10.5 | 15 | 20 | 25 |
Ion transfer tube temp (°C) | ||||||
TSQ Altis Plus, | 325 | 325 | 325 | 325 | 380 | 380 |
TSQ Quantis Plus, | 300 | 300 | 300 | 325 | 350 | 375 |
TSQ Fortis Plus | 275 | 275 | 300 | 325 | 325 | 350 |