Skip to main content
. Author manuscript; available in PMC: 2014 Sep 1.
Published in final edited form as: J Pharm Biomed Anal. 2013 Apr 16;83:1–9. doi: 10.1016/j.jpba.2013.04.007

Figure 3. Ion suppression test using continuous post-column infusion.

Figure 3

Blank human EDTA plasma samples from ten different healthy individuals were extracted and injected into the LC-MS/MS system. A representative experiment is shown Acetaminophen (10 μg/ml dissolved in 01 formic acid/acetonitrile, 3:7, v/v) was infused post-column via T-piece at a rate of 10 μl/min using a syringe pump (Harvard Apparatus, Holliston, MA). The extent of ion suppression was established by monitoring the signal intensity of the ion currents in MRM-mode (m/z= 152 [M+H]+ → 110) at the retention times of the analyte (marked by arrow) after injection of blank extracted plasma samples into the LC-MS/MS system. Ion suppression would have caused a “dip” in the acetaminophen signal produced by constant infusion. The arrow marks the retention time of acetaminophen. Red: continuous infusion of acetaminophen, blue: overlaid analysis of extracted sample with acetaminophen peak.