• Use the highest temperature possible when optimizing compounds. A temperature of 700
°C is common for many compounds. High temperatures help keep the ion source clean and
reduce background noise.
• Use the highest possible value for the flow rate of the gas for the Curtain Gas interface that
does not sacrifice sensitivity. This helps to:
• Prevent penetration of the flow of gas for the Curtain Gas interface, which can produce a
noisy signal.
• Prevent contamination of the aperture.
• Increase the overall signal-to-noise ratio.
• Adjust the horizontal micrometer setting to direct the liquid spray from the probe away from
the aperture to:
• Prevent contamination of the aperture.
• Prevent piercing of the flow of gas for the Curtain Gas interface, which can create an
unstable signal.
• Prevent electrical shorting due to the presence of the liquid.
To do so, use the vertical micrometer to move the probe up.
• Use the lowest ion source voltage possible without losing signal. Focus on signal-to-noise
and not just signal.
• For flow rates greater than 2 mL/min in APCI mode, equilibrate the mass spectrometer before
starting the liquid flow, to make sure that the nebulization temperature is reached.
Ion Source Optimization
SCIEX 3200 Systems
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System User Guide
RUO-IDV-05-6475-C
