He K, Kozak M.
Slide Presentation
• We have tested the detection of testosterone with LC-MS/MS using three ionization
techniques: HESI, APPI and APCI.
• With most of the source parameters consistent, the order of signal intensity of ionized
testosterone is (from highest to lowest): APCI, APPI and HESI.
• We can detect 5 pg/mL testosterone in neat solutions with both APPI and APCI, but not
HESI (>50 pg/mL), under the current conditions.
• While APPI ranked in the middle in terms of signal intensity, the background signals were lowest. And we observed excellent calibration curve.
• Regardless of the ionization technique, we observe the consistent ion ratio between the two major fragment ions.
• Due to multiple reasons, we did not add dopant for APPI, which might further improve the performance.
• Concentrations of testosterone in this presentation were the straight-up values in the
glass inserts. For real samples, we will have 2 concentration factor and it will improve
LLOQ by ~ 2 fold.
Thermo Fisher Scientific
United States
