Which statement regarding mass spectrometry is false?

Which statement regarding mass spectrometry is false?

• A. Mass spectrometers can be used to sequence DNA
• B. Ions are formed by the bombardment of electrons
• C. Quadrupole and ion trap sectors separate ions according to their mass-to-charge ratio
• D. Each chemical compound has a unique mass spectrum

Answer: (A)

Mass spectrometry provides masses and fragmentation patterns of ions, which is excellent for identifying molecules and their substructures, but sequencing DNA isn’t done with this technique in routine practice. Determining the exact order of nucleotides in a DNA molecule requires sequencing methods such as Sanger or next-generation sequencing, whereas mass spectrometry can analyze the masses of nucleotides or short fragments but doesn’t read long DNA sequences directly. The other statements reflect true aspects: ions can be formed by electron impact in certain ionization methods; quadrupole and ion trap components separate ions by their mass-to-charge ratio; and a given compound tends to produce a distinctive mass spectrum that helps identify it.

Mass spectrometry provides masses and fragmentation patterns of ions, which is excellent for identifying molecules and their substructures, but sequencing DNA isn’t done with this technique in routine practice. Determining the exact order of nucleotides in a DNA molecule requires sequencing methods such as Sanger or next-generation sequencing, whereas mass spectrometry can analyze the masses of nucleotides or short fragments but doesn’t read long DNA sequences directly. The other statements reflect true aspects: ions can be formed by electron impact in certain ionization methods; quadrupole and ion trap components separate ions by their mass-to-charge ratio; and a given compound tends to produce a distinctive mass spectrum that helps identify it.