Sugars and Organic Acids Analysis with RID

[kjordan]

We are creating a new protocol for analyzing our samples for sugars and organic acids. We have a Shimadzu HPLC with RID and are using a Shodex SUGAR SH1011 column with a guard column. With this HPLC, we have only used a different column to measure sugars. We made a combined sugar (sucrose, glucose, and fructose) stock standard for those calibration curves and diluted it to get the rest of the curve. My question is how we should handle the organic acids and sugars for this new calibration. It will be those same three sugars and four organic acids. Should we make two stock solutions (one for sugars and one for organic acids) or one combined with all 7 components? We were thinking of 1 combined, but I am not getting much feedback and only have about 1 month's hands-on experience with HPLC. Also, I'm having trouble figuring out the stability of these standard solutions once they are made and determining how long we can store them. I saw somewhere that the sugar solutions could be stored 2 weeks in the fridge but did not see much background. Thanks!

[georgelin]

This is very normal application for RID. Sugar/Organic Acid should be kept in the fridge. Otherwise, there will be bacteria growth in the solution. I am assuming that sugar/organic acid are dissolved in water.

Best regards

George

We are creating a new protocol for analyzing our samples for sugars and organic acids. We have a Shimadzu HPLC with RID and are using a Shodex SUGAR SH1011 column with a guard column. With this HPLC, we have only used a different column to measure sugars. We made a combined sugar (sucrose, glucose, and fructose) stock standard for those calibration curves and diluted it to get the rest of the curve. My question is how we should handle the organic acids and sugars for this new calibration. It will be those same three sugars and four organic acids. Should we make two stock solutions (one for sugars and one for organic acids) or one combined with all 7 components? We were thinking of 1 combined, but I am not getting much feedback and only have about 1 month's hands-on experience with HPLC. Also, I'm having trouble figuring out the stability of these standard solutions once they are made and determining how long we can store them. I saw somewhere that the sugar solutions could be stored 2 weeks in the fridge but did not see much background. Thanks!

[kjordan]

Yes, we have been keeping the standards in the fridge for no longer than 2 weeks. I was not sure if that was appropriate. I could only find one source that blatantly said how long they could be stored. Also, I wanted to make sure that combining all the sugars and organic acids into one standard solution was the best practice.

This is very normal application for RID. Sugar/Organic Acid should be kept in the fridge. Otherwise, there will be bacteria growth in the solution. I am assuming that sugar/organic acid are dissolved in water.

Best regards

George

We are creating a new protocol for analyzing our samples for sugars and organic acids. We have a Shimadzu HPLC with RID and are using a Shodex SUGAR SH1011 column with a guard column. With this HPLC, we have only used a different column to measure sugars. We made a combined sugar (sucrose, glucose, and fructose) stock standard for those calibration curves and diluted it to get the rest of the curve. My question is how we should handle the organic acids and sugars for this new calibration. It will be those same three sugars and four organic acids. Should we make two stock solutions (one for sugars and one for organic acids) or one combined with all 7 components? We were thinking of 1 combined, but I am not getting much feedback and only have about 1 month's hands-on experience with HPLC. Also, I'm having trouble figuring out the stability of these standard solutions once they are made and determining how long we can store them. I saw somewhere that the sugar solutions could be stored 2 weeks in the fridge but did not see much background. Thanks!

[Multidimensional]

TWO weeks is a long time to keep sugar/organic acids in solution within the refrigerator. I would imagine a lot of bacterial growth would occur during that time. The pH of the solution may also change too. It would have to be professionally tested to know for sure, 100%, but general policy with HPLC solutions, esp standards, would be to prepare FRESH solutions every few day (store in refrigerator during that time). Make up only what you will need or use in 2 or 3-days. This is how we would do it in a professional laboratory following GLP. Preparing solutions fresh is easy to do. Make sure you work with an experienced chromatographer too. No one can learn HPLC in a month or year, esp not without full-time professional help.