The matrix effect in organic secondary ion mass spectrometry

•We demonstrate the capability to produce thin mixed organic films of known composition as reference materials for surface mass spectrometry.•We demonstrate that different secondary ions from the same material may be enhanced or suppressed by different amounts in mixtures.•We show that different secondary ions appear to originate from different depths and show how this effect can be mitigated in a depth profile.•We introduce a measure of the magnitude and sign of the matrix effect in mixed organic materials.