Pectin (galacturonic acid) analysis

Record: 105

Category: Column Selection
Product: NH2P-50, KC-811
Sample: pectine (galacturonicacid)

Question
They need to quantify pectin (galacturonic acid) and they found several methods in the literature and most of them uses RI detectors which they do not have.

I found and shoed her an application in your catalogue for oligogalacturonic acid perform on the Ashahipak NH2P

http://www.shodex.com/english/dc030901.htmlà

They were really interested but wanted to know more about the method.

Did you have to do a treatment to the compounds prior to HPLC analysis? What was the preparation?

Also the peak # 1 Galacturonic acid is very small, is it because the concentration is very low?
They have a product that contains as ingredient PECTIN. They need to quantify the amount (CONCENTRATION) of pectin in this product. Pectin is a complex polysaccharide. The pectin contain a variable number of methoxy and galacturonic acid. The exact moleculare weight of pectin does exist. The composition, structure and physiological properties of pectin might be influenced by conditions of extraction as well as sources, locations and many other environmental factors. To measure the pectin in the food, usually acid hydrolysis is used to degrade the pectin molecule to galacturonic acid, the main constituent of pectin. Therefore, they’d like to quantify the amount of galacturonic acid (concentration). Ideally, they would like to have only one peak which represent the galacturonic acid. They don’t need the MW distribution analysis of pectin. They have 2 alliances de Waters with PDA detector. The solfware use is Em power.

Answer
In this case, the analyte is in “galacturonic acid state” from the sample pretreatment, I think the one you suggested using NH2P50 column will be the better recommendation.

Since the chromatogram is not from our own data, I’m sorry I couldn’t find the information what concentration was used. However, based on our other study (attached) we can estimate using UV as a detector, detection limit (S/N =3) of galacturonic acid will be about 1.5ppm level.
As the attached condition shows, KC-811 will be another option. But I think NH2P50 would be easier to work with.

 
 
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