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Lost signal intermediate standard ICS 5000

Posted: Tue Feb 06, 2018 8:35 am
by HWEJON
HI,

I work with an ICS5000 to analyze sugars in foods with a PA10 column Thermo.
Our sequences are 30-40 samples,every 5 samples we put a intermediate standard to control time and area displacements, the analysis lasts one hour each sample.

we observed falls of areas in the intermediate standards regarding the same standar of calibration by 20-30%, this interferes with low results in the samples.

Why is this happening?

Thank you very much!!!!

Re: Lost signal intermediate standard ICS 5000

Posted: Tue Feb 06, 2018 7:53 pm
by John Guajardo
Hi HWEJON,

Please check the age and condition of your working electrode and reference electrode. The reference electrode should typically be replaced every 3-6 months on ICS-5000 systems and is usually only calibrated during replacement. A bad reference electrode can produce very strange baseline behavior, cause decreased sensitivity, and/or lead to shorter disposable working electrode life. I would recommend installing a new reference electrode (061879 - ELECTRODE ASSY, REF, AGCL) , calibrating it, installing a new disposable working electrode, then checking your response to see if it returns to normal and stabilizes.

Re: Lost signal intermediate standard ICS 5000

Posted: Wed Feb 07, 2018 6:58 am
by HWEJON
Hi,


Thanks John for the answer!! I'll change the electrode 061879.

We also work with work electrode 061875 that we polish, but every time the working electrode is changed????

We work with the ICS5000, PA10 column for samples of low-level sugars for samples with proteins and fats we use the onguard II cartridge, Is this enough cartridges to clean the sample?

Do you recommend working with inGuard sample prep cartidge? which would be the most suitable for our samples with proteins and fats.

The Inguard cartridges replace the Onguard or are you working with both?



Thaks!!!

Re: Lost signal intermediate standard ICS 5000

Posted: Wed Feb 07, 2018 8:03 pm
by John Guajardo
Hi HWEJON,

My apologies, I assumed that you were using our disposable gold electrodes (060139 or 066480), which are easy to replace when troubleshooting.

Please contact me directly (john.guajardo@thermofisher.com) regarding your sample matrix and typical sample prep procedure with our Dionex OnGuard cartridges, and I will discuss with R&D to find the best solution for you.