Peeke Scientific Inquiry

Record: 451

Category: General
Product: AAV-894
Sample:

Question
do you use reagents that are HPLC level (sodium acetate, sodium phosphate, etc- are there reagents like that HPLC grade?)

– do you prefer sodium phosphate anhydrous or with water molecules – what is better for HPLC applications, why?

– for preparing for example the 0.01M Sodium acetate buffer (pH 7.0) + 0.15M NaCl: do you just calculate the concentration
based on the MW (0.82 g of sodium acetate (to get 0.01 M), and 8.7 g of NaCl (to get 0.15 M), then you dissolved it 1 L HPLC water)
and after that you filter the solution (like I do for regular HPLC water that I use?)?

– in the second buffer with 0.02% NaN3 – is that 0.02 (w/v) that mean that in 1 liter of solution I should add 0.2 g of NaN3?

Answer
Nothing much different for affinity column regarding the mobile phase. Please let me know if they have further question.
Kanna

– do you use reagents that are HPLC level (sodium acetate, sodium phosphate, etc’ – are there reagents like that HPLC grade?)
Yes, for the use with UV, we always recommend to use HPLC grade. Since lower grade may give UV absorption from the impurity and may cause interfering peaks or noisy baseline.

– do you prefer sodium phosphate anhydrous or with water molecules – what is better for HPLC applications, why?
It does not really matter as long as the mobile phase contain the same molarity of phosphate i.e, the molarity of phosphate in phosphate anhydrous and hydrated salts will be different. However, you may probably can obtain repeatable (more accurate concentration) solvent by using the anhydrous salt since weight of hydrated salt can differ depends on the storage condition. For the same reason, you should keep the anhydrous salt from getting moist.
e.g. http://www.sigmaaldrich.com/catalog/ProductDetail.do?lang=en&N4=71185|FLUKA&N5=SEARCH_CONCAT_PNO|BRAND_KEY&F=SPEC

– for preparing for example the 0.01M Sodium acetate buffer (pH 7.0) + 0.15M NaCl: do you just calculate the concentration based on the MW (0.82 g of sodium acetate (to get 0.01 M), and 8.7 g of NaCl (to get 0.15 M), then you dissolved it 1 L HPLC water) and after that you filter the solution (like I do for regular HPLC water that I use?)?
Yes, but you should mass up with water to make the solution 1L. Few g difference, but you should not dissolve in 1L water, instead, dissolve the salt in ~500 mL water first, then add up the volume to make it 1L.

– in the second buffer with 0.02% NaN3 – is that 0.02 (w/v) that mean that in 1 liter of solution I should add 0.2 g of NaN3?

Yes.

 
 
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