No analyte peaks

[Helicase428]

Need help with Integrion Anion IC.  I've attached some pics one is a normal chromatogram.  I think we may have a suppressor leak. The current suppressor was just installed.  The guard column, analytical column, and EGC have been changed out as well.   But the peak after the water dip is perplexing as well as the eluent concentration change in the middle.  Any help would be appreciated.  Thanks.

[GeorgeTFS]

Hello @Helicase428  and welcome to the community!  My first go-to would be @The_Ion_Lady . Let's see if she has any suggestions. (Please know that she is on a different time zone, so there could be a delay in response)

[The_Ion_Lady]

@Helicase428 , can I ask a few questions to establish a few things first? 

• what is the total conductivity background as the photos of your chromatography are showing the autozeroed background?
• Does the Standards look the same as you PERF samples?
• What does your deionized water blank injection look like?
• What is the pressure of the system?
• What columns are you using?

It would be easier for me to look at the Chromeleon backup file for all the information. Have you logged this with our Level 1 technical support? (https://www.thermofisher.com/uk/en/home/technical-resources/contact-us.html?supportType=SR)

Usually, the "water-dip" is the conductance difference between the sample and the eluent used. In some cases, the peak at the dip can be from a large excessive amount of counterion (in anions, they will be cations), OR it could be early eluters such as acetate that maybe in the water from a new filter cartridge in the water purifiers. 

I look forward to your further information.