Hydrxoxyproline interference

[simon.leclair2]

We have a contamination or interference for the hydrolysate sample of hydroxyproline analysis. We think it is the product that we use that is the problem, because we can see a peak in the retention time of the hydroxyproline in a method blank. We have an 30-40 fold overestimation of our hydrolysate sample. We can see a shoulder peak or a split peak in those samples. Beside a contamination or interference problems coming from my product, do you have any other suggestion why I have a peak of hydroxyproline in a method blank?

My method that I use is :
1. The acid hydrolysis with 6 N HCl + 1% phenol for 24 hours at 110°C.
2. SPE with the Dowex resin.
3. Analyze with the 1290 infinity HPLC-DAD with an OPA and FMOC derivatization.
Column : InfinityLab Poroshell HPH-C18 4.6 * 150 mm 2.7-micron
Mobile phase A : 10 mM Na2HPO4 7H20 and 10 mM Na2B4O7 10H20
Mobile phase B : ACN:MeOH:H20 (45:45:10).

[hossam kamal]

Can you attach a chromatogram please so we can help you !!!! and if it possible another chromatogram of blank injection

[simon.leclair2]

Can you tell me how can I put a picture in this forum? I can't found the option.

Thanks

Simon

[dblux_]

Can you tell me how can I put a picture in this forum? I can't found the option.

Thanks

Simon

viewtopic.php?f=1&t=2617

[HPLC chemist]

If I recall my organic chemistry Hydroxyproline is due to the hydrolysis of Tryptophan.

[hossam kamal]

i think you can upload it to google drive and share its link , we can get to it

[simon.leclair2]

You can see my chromatograph with this link : https://drive.google.com/open?id=1MiXRC ... tIOoBbcTEM. Thanks for the information hossam kamal.

[simon.leclair2]

HPLC Chemist I don't have this information, but I think the hydroxyproline is synthesis with proline. dblux, thanks for the information, but the way of hossam kamal was more easy.