Capillary columns require conditioning prior to their first use.Typical conditioning is washing with 1 M NaOH for 1 hour,followed by 1 hour of water,then 1 hour of 6 M HCl,and finally 1 hour of run buffer.Which statements are INCORRECT?
I The NaOH wash is thought to generate the Si-OH groups on the silica surface.
II The NaOH wash removes any acidic contaminants from the silica surface.
III The HCl wash is thought to generate the Si-OH groups on the silica surface.
IV The HCl wash removes metal ions from the capillary surface.
A)I and III
B)I and IV
C)II and III
D)II and IV
E)I,II,and III

Question

Quizplus · Accepted Answer

Statement I is correct, as the NaOH wash is known to generate Si-OH groups on the silica surface. Statement II is incorrect, as the NaOH wash removes basic contaminants, not acidic ones. Statement III is incorrect, as it is actually the HCl wash that generates Si-OH groups on the silica surface. Statement IV is correct, as the HCl wash is used to remove metal ions from the capillary surface. Therefore, the only incorrect statements are II and III, making choice C the best answer.

Capillary Columns Require Conditioning Prior to Their First Use