tech tips pdf v2
tech tips Certificate of Analysis Water Content
We often get asked whether the purity value provided on the Certificate of Analysis already accounts for the water content. Yes it does.
lgcstandards.com
tech tips Water content is provided for you on the Certificate of Analysis for information only.
1
If the product is not a hydrate, then the water content is not part of the chemical compound and has been considered as an impurity when calculating the purity found on the Certificate of Analysis.
2
For chemicals that are hydrates, water is part of the chemical and so it is not an impurity. If you buy a hydrate and want to calculate the purity for the water free substance, you have to subtract the water content from the purity. A non-hydrate equivalent may be available to purchase if the water free substance is required.
3
For compounds in solution, the certified value is the concentration of the material. The concentration of the solution is exact (as it has taken into account the purity of the neat substance used in the solution).
@ [email protected] lgcstandards.com
Science for a safer world
These tech tips are intended for general information purposes only. They should not be interpreted so as to override your own laboratory procedures (SOPs) and applicable good laboratory practice. Dr. Ehrenstorfer and the LGC Group regret they cannot accept liability for any loss occasioned by your misuse of any reference material supplied. Copyright LGC Limited, 2017. All rights reserved. Dr. Ehrenstorfer is a trademark (owned by LGC Limited) and registered in certain territories, including EU, US, China and Japan.
We often get asked whether the purity value provided on the Certificate of Analysis already accounts for the water content. Yes it does.
lgcstandards.com
tech tips Water content is provided for you on the Certificate of Analysis for information only.
1
If the product is not a hydrate, then the water content is not part of the chemical compound and has been considered as an impurity when calculating the purity found on the Certificate of Analysis.
2
For chemicals that are hydrates, water is part of the chemical and so it is not an impurity. If you buy a hydrate and want to calculate the purity for the water free substance, you have to subtract the water content from the purity. A non-hydrate equivalent may be available to purchase if the water free substance is required.
3
For compounds in solution, the certified value is the concentration of the material. The concentration of the solution is exact (as it has taken into account the purity of the neat substance used in the solution).
@ [email protected] lgcstandards.com
Science for a safer world
These tech tips are intended for general information purposes only. They should not be interpreted so as to override your own laboratory procedures (SOPs) and applicable good laboratory practice. Dr. Ehrenstorfer and the LGC Group regret they cannot accept liability for any loss occasioned by your misuse of any reference material supplied. Copyright LGC Limited, 2017. All rights reserved. Dr. Ehrenstorfer is a trademark (owned by LGC Limited) and registered in certain territories, including EU, US, China and Japan.
