Question

Why acetonitrile is used as solvent in HPLC?

(a) Improve chromatographic peak shape

(b) Provide a source of protons in reverse phase LC/MS

(c) Provide a source of electrons in reverse phase LC/MS

(d) Improve chromatographic peak shape and provide a source of protons in reverse phase LC/MS

The question was posed to me in semester exam.

This interesting question is from Absorption Mechanisms topic in chapter Absorption of Food Processing Unit Operations

Answer 1

Correct answer is (d) Improve chromatographic peak shape and provide a source of protons in reverse phase LC/MS

The best I can explain: In High pressure liquid chromatography, the B solvent used is HPLC grade organic solvent like acetonitrile, methanol with 0.1% acid. This acid is used for improving the shape of chromatographic peak and to provide source of protons in the reverse phase LC/MS.