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- Posts: 16
- Joined: Tue Aug 06, 2019 10:34 am
We have an analyte eluting at 3.3 minutes. The standard and spiked standard solution gave one, sharp peak at 3.3 minutes. But, when we spiked materials with a spiked standard solution, we saw a peak eluted earlier than our main peak and lies close to it, please see the attached images.
I've checked the UV spectrum of both peaks and they are highly similar. Any idea what can be the root cause of it?
I've tried:
1. Swab blank
2. Placebos blank
3. Matrix Blank
4. Standard only solution
5. Swab and standard only solution
6. Swab and spiked standard only solution without swabbing.
No co-elution nor presence of a peak at that time.
These are performed on Agilent 1290 binary pump HPLC
Mobile Phase: A- 0.05% TFA in purified water
B- 0.05% TFA in Acetonitrile
Column: Zorbax Eclipse Plus C18 RRHD 1.8um, 2.1mmX50mm
Gradient mode of 0.6ml/min, 6.4 mins run time, 1.5 min post time