By trangcatherine on Thursday, March 23, 2000 - 03:58 pm:
Hi,
We prepare 2,3,4,6-tetra-O-benzyl-D-glucopyranosyl chloride from 2,3,4,6-tetra-O-benzyl-D-glucopyranose in the presence of thionyl chloride. I need to analyse the startind material and the product at the same time. I have been trying HPLC but not able to detect the starting material. I do not have any experience with sugar compounds.
Could somebody suggest any method by HPLC to analysing such compounds, please?
I read in chormatography catalogs, they mention about derivatising the sugar but if I do not want to , is there any direct way to analysing that?
Thank you in advance.
By Uwe Neue on Thursday, March 23, 2000 - 04:33 pm:
If I understand you correctly, you are looking for a method to detect underivatized sugars. The classical method to do this is to use a refractive index detector. There are more sophisitcated methods around, but for your purposes it seems that the refractometer is the right choice.
By trangcatherine on Thursday, March 23, 2000 - 05:10 pm:
Hi Neue,
thank you very much for your suggestion but!!but! we do not have the refractometer!
What else could I do?
Thanks,
C.
By Joseph A. Runkle on Monday, March 27, 2000 - 09:34 am:
You have a wonderful chromophore in this case (the four benyl rings), so I suspect that, since you are seeing the chloride but not the pyranose, your problem lies in the chromatography rather than the mode of detection. It may be that the starting material is much more strongly retained than you think. Do you happen to be using a C18 column? Also, what is your mobile phase? If you are using a octadecyl column, you may want to consider changing to an octyl silane to lessen the retention of the pyranose (assuming that the chloride is retained fairly well). I hope this helps.
By trangcatherine on Monday, March 27, 2000 - 04:13 pm:
Hi Joseph,
I use YMC-ODS AP-302 column with CH3CN/0.5% H3PO4 as mobile phase and the pyrranose chloride elutes at about 5.9 min. (detector at 220 nm, oven 40C)
As you said, the starting material is probably strongly retained on the column!
CTP
By trangcatherine on Monday, March 27, 2000 - 11:40 pm:
Hi,
If the pyrranose chloride is not stable in such condition mentioned aboved since I observed the broad small peak eluted before the pyranose chloride peak , which I suspected the decomposed product(?), is there any other more stable condition for such chloride compound to be analysed?
Thanks
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