Question

Which of the following is not true about the guard column used in liquid chromatography?

(a) It filters particles that clog the separation column

(b) It extends the lifetime of separation column

(c) It allows particles that cause precipitation upon contact with stationary or mobile phase

(d) The size of packing varies with the type of protection needed

This question was addressed to me in a job interview.

Asked question is from Liquid Chromatography topic in portion Chromatography of Analytical Instrumentation

Answer 1

The correct answer is (c) It allows particles that cause precipitation upon contact with stationary or mobile phase

To explain I would say: Guard column removes particles that cause precipitation upon contact with stationary or mobile phase. It is placed before the separation column.