hi, If SWIM would buy some NaOH, what kind should he get? Is technical grade NaOH ok, or should he go for the 4 times more expensive pure NaOH?

I get my NaOH from 'Het Kruidvat' where it is known as 'gootsteenontstopper'. It is very cheap and works like a charm.

ah ok, then i think its technical grade, otherwise you wouldn't call it cheap the pure NaOH SWIM found was like 25$/kg technical grade is like 5 bucks for the same...

"Kruidvat ontstopper" says to be 15% NaOH, but is silent for the rest of the 85%?

I checked on another brand from "Colruyt" and said to be 10% NaOH, and stated also "additional excipients" (hulpstoffen, additives) but say not what they are and how many. I'm wary about those extra's for not to consume any dangerous stuff.

So even when there are "excipients", should I worry? I guess that when those excipients stay in the liquid then there is no danger as we take the precipitations only, UNLESS those excipients will bound themselves with the precipitations. Can we take for granted that all precipitations are free of possible bounds with possible additives of the chemical plunger?
Many thanks.

I think you would do best to use 99%+ NaOH and avoid products with other chemicals mixed in to them. Look at the MSDS or other sources listing the ingredients for a particular product to be properly informed. If you are careful, NaOH is one of your best friends in extractions.

Working with "for analysis" grade now, but want a good source when its empty.
Seems labstuff.nl has a good range.

Drain openers carry sometimes thickeners for making it more syrup.

Hello,

So I took a look at the product range of a "real" chemical supplier...

They have NaOH in such a variety that it blows my mind...

Apart from purity being expressed as a percentage, there are also differences depending on intended use of the product...e.g. specially for biochemistry they have NaOH that doesn't contain mercury or arsenic (+100 euros per kg)...

Even more confusing, sometimes 96% purity is approved "Pharmacopeia..." while there's also 98% purity that isn't "Phar, Eur."...

And what about "purified", "purum" and "puriss"? (I looked them up, which only slightly reduces confusion)

So, purity percentages do not tell the whole story and msds sheets rarely state which impurities are in a product...They just say, e.g., < 1% and that it's within acceptable limits, but is this 1% arsenic? butterfly pee? who knows?

With prices ranging from a few euros per kilo to over a hundred, I would gladly invite you to look at the page I mentioned and tell me, which do you think is best value for money/least health risk...

http://www.sigmaaldrich....;mode=match%20partialmax

Don't forget to click "show all 18 results"

PLUR

PS Semi-conductor grade? Ever heard of that?

I am wondering about purity grades for extractions as well. I can get 99.4% pure NAOH from a chemical company, but they have it listed as industrial grade. It's just over a dollar for a kilo.

They also have industrial grade Calcium Hydroxide for about 50c per kilo. It says its 93% pure in the analysis sheet. I am assuming that a large part of the remaining percentage is probably calcium carbonate, but have no way to be sure.

So I am wondering if either of these would be safe to use. Obviously food grade reagents are better, but I am in a place where such things are hard to find.

Considering that I do not intend to ingest the reagents, and that they are only being used to basify a solution before pulling and then salting. Does anyone with some chemical background know how crucial the purity of the ingredients needs to be ?