Figure 3.

Analyte spiking experiments that were used to demonstrate that ion suppression by matrix components, rather than analyte recovery was the primary contributor to loss of signal. Panels A-D show increasing analyte signal with increasing dilution of matrix. Panels E-F show that analyte was not detected even when spiked into matrix after cleanup, just prior to analysis. Panel G shows the LC-MS/MS analysis of 5 fmol of analyte and internal standard for comparison.