Mass specs would have this problem, yes. That's why they are usually paired with chromatography of some sort (usually GC/MS or LC/MS). The GC or LC more or less

Mass specs would have this problem, yes. That's why they are usually paired with chromatography of some sort (usually GC/MS or LC/MS). The GC or LC more or less reduce a mixture into components, which are fed into the mass spectrometer to analyze what those components are.