JCU
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Precision issues - 2007/02/19 08:40
Dear Experts,
I am noticing poor agreement between my replicate samples. I am analysing thyroxine and am finding typically that there is a 1% difference between the replicates (calibration samples) and up to 2% in the actual samples. The actual samples are the thyroxine extracted from tablets, using mobile phase and filtered (0.22u).
Peak purity analysis says that the peaks are pure but this loss of precision is worrying. What could I do to rectify this situation? I can't see any leaks.
Varian HPLC Prostar, PDA, C18, 0.2%Phosphoric acid/Acetonitrile 45:55, 255nm, 1mL/min, column warmed:35deg.
kind regards
Martina
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Martina
User
| Posts: 1 | |
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Re:Precision issues - 2007/04/19 11:14
Hi,
Thank you to those experts who replied to my initial post. I am not sure where those replies are now but I just wanted to post that I replaced the syringe assembly on my Varian prostar and that solved my reproducibility issues.
Thanks again
Martina
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