Sodium Perchlorate in Mobile Phase

[Chris]

I am looking at the Pharmacopoeia methods for the analysis of Tylosin and they all contain Sodium Perchlorate in the mobile phase (aqueous solution with Acetonitrile at pH 2.5). Due to the risks associated with this material I would like to swap it for something else. What role does the Sodium Perchlorate play in mobile phases, is it simply a buffer that can be exchanged for something else?

[Mark Tracy]

Perchlorate is an ion-pairing agent, about as strong as trifluoroacetate. NaClO4 is a neutral salt that does not buffer. Its main virtue is UV transparency. You can try a short-chain sodium alkanesulfonate as a substitute.