By Txus on Thursday, October 2, 2003 - 08:48 am:
I have been doing runs on the USP/Eur.Pharm method for months, and it performed well. But lately, doing a lot of injections during the same day, the retention time increase almost 2 min. Its very suspicious that USP method says that increasing the % of ACN , the Rt decreases, as its a common rule. Any ideas? Any column type suggestion?
By A.Nonymous on Thursday, October 2, 2003 - 10:43 am:
Maybe your bottle with mobile phase wasn't well sealed, so the ACN was maybe evaporated.
ACN% decreased so Rt increased.
Just an idea.