[Hocks88]

Good day fellow scientists!

Long term reader, first time poster! How very exciting.

I have been an analyst at a pharmaceutical company for a couple of years and have recently started as a QA/QC manager for a new start-up company. So far it's going very well indeed (thanks for asking ), apart from one niggling issue thats being a right thorn in my side...

It seems the nomograph used for calculating the hydrogen peroxide concentration in one of our water solutions has been misplaced/destroyed/vapourised/stolen by a spooky ghost during the liquidation of the previous company based here. I was wondering if anyone knew of anywhere I could find a replacement OR could suggest a handy calculation that I could use to work it out the good old fashioned way?

The two axis are the temperature and the relative density of the solution. I have been informed by colleagues that common readings were;

* Temperature of Water/H2O2 solution = between 20-22°C
* The relative density (measured using a hydrometer) = around 1.13 - 1.14
* The nomograph would then give a relative concentration of hydrogen peroxide of 35-40%

Iv spent many hours this week trawling the internet to try and find a solution and it's starting to drive me crazy. I wouldnt bother you busy bunch if I didnt feel it necessary for my crumbling sanity! Therefore 'UTFSE' and alike responses should be used with caution as they would hurt my feeling (I only have one) greatly, and might just be enough to push me over the edge...

Thanks in advance for checking out my rather trivial problem that no doubt has a very simple solution, but any input or advice would be greatly appreciated!

[Borek]

Welcome to the forum.

Nomogram is just a fancy way of using the density information - perhaps you can find density tables for different temperatures and construct your own nomogram? The only source I can think of at the moment (International Critical Tables) contains densities for 4°C and 15°C, so it doesn't cover the temperature range you are interested in (you can do linear extrapolation, but it is always a risky business).

To some extent you could use my CASC for conversion between density and concentration, as it does contain density table for H₂O₂ solutions, but I think it is for 15°C, so it won't work for other temperatures. Still, if you will find the tables for other temperatures you can enter them into the program and use it for conversion.

[Arkcon]

I suppose if it is just hydrogen peroxide in water, you may be able to find a reference.  If the solution contains a number of other ingredients, then you will have to determine it again, by making up a variety of solutions at different levels.  IMHO, you should probably do that anyway, you will want to have this data in a safe place, validated by the head of QA/QC (you!), to show that your new company is attending to your customers health, safety, and application's needs.

[MOTOBALL]

I remember ordering high test H2O2 (ca. 90%) in 1969/70 in the UK, but cannot recall the supplier with any certainty. (Albright & Wilson ??)

Would suggest that you search for such a supplier, and ask them if they have the nomograph.

Alternatively, search "Kirk-Othmer Encyclopaedia of Technology" at local univ. library.