Question

Which ionization technique in mass spectrometry is most suitable for large biomolecules like proteins:

• A. Chemical Ionization (CI)
• B. Physical Ionization (PI)
• C. Electron Impact (EI)
• D. Electrospray Ionization (ESI)

Hint:

Electrospray Ionization (ESI) is the preferred technique for analyzing large biomolecules like proteins, as it gently ionizes them while preserving their structure.

Answer 1

The Correct Option is D

Step 1: Understanding mass spectrometry ionization techniques. Mass spectrometry involves ionizing molecules for analysis based on their mass-to-charge ratio. Different ionization techniques are used depending on the type of molecule being analyzed. 

Step 2: Suitability of ESI for large biomolecules. Electrospray Ionization (ESI) is highly suitable for large, polar biomolecules like proteins due to its gentle ionization process. It converts biomolecules into ions without significant fragmentation, preserving their structure. 

Step 3: Why other options are not suitable. 
- (A) Chemical Ionization (CI): Suitable for small to medium-sized molecules, not large biomolecules. 
- (B) Physical Ionization (PI): Not a recognized standard ionization technique in mass spectrometry. 
- (C) Electron Impact (EI): Causes extensive fragmentation, making it unsuitable for delicate biomolecules like proteins.