Always make sure your sample jar is clean

[Rossey]

This had me stumped for a while 

[Julian]

All my sampling and testing kit goes in the dishwasher accompanied by lots of grumbles from the domestic authorities.

[Jamesrl]

My test kit gets cleaned with IPA and dried before any testing is undertaken.

I also clean me sample vessel before each use, we don't want anything from the last sample contaminating the current one do we?

[nigelb]

Someone once told me that the removal of any traces of soap/detergent used in the cleaning of glasswear can take as many as 9 clean water rinses.

He used to work in a lab.

No idea if it's true or not but I had no reason to disbelieve him

[Rossey]

My test kit gets cleaned with IPA and dried before any testing is undertaken.

I also clean me sample vessel before each use, we don't want anything from the last sample contaminating the current one do we?

that's brilliant idea, didn't think of that.

was starting to wonder if I should clean my flask.

[nigelb]

You could always do as I do and use a bit of methanol as a final rinse of the glass

[Glycer-rides]

I swill out residue with Acetone, me.
Not that there's any veg left...but if so, add to the next cubie of fuel.

[Bill]

Someone once told me that the removal of any traces of soap/detergent used in the cleaning of glasswear can take as many as 9 clean water rinses.

He used to work in a lab.

No idea if it's true or not but I had no reason to disbelieve him

I believe it. Its the principal of successive dilution of a contaminant. Each small rinse takes away some but not all the contaminant. Several small rinses will be more effective that one big rinse using the same total volume of flushing agent. Also depends on solubility's, etc., so methanol is not the best rinse agent for veg oil, IPA would be better.

[Rossey]

Someone once told me that the removal of any traces of soap/detergent used in the cleaning of glasswear can take as many as 9 clean water rinses.

He used to work in a lab.

No idea if it's true or not but I had no reason to disbelieve him

I believe it. Its the principal of successive dilution of a contaminant. Each small rinse takes away some but not all the contaminant. Several small rinses will be more effective that one big rinse using the same total volume of flushing agent. Also depends on solubility's, etc., so methanol is not the best rinse agent for veg oil, IPA would be better.

ipa isn't soluble with veg oil either tried that before.

[julianf]

Veg is soluble in IPA - back when titrations were in fashion, we all used IPA as the solvent.

[nigelb]

I dont use just methanol or IPA to rinse my glasswear. I think that usage of these two alcohols as a stand alone could be seen as fool hardy.

I put a squirt of washing up liquid in the glass clean it out with vigorous shaking...the glass, not me..followed by several rinses and then a few ml of methanol as a final rinse.

[Rossey]

Veg is soluble in IPA - back when titrations were in fashion, we all used IPA as the solvent.

It does seperate, I used to be able to get free so was goin to use it to thin the veg.

So tried a sample, It had split in 10 minutes.

[Tony]

I believe most labs rinse with acetone.  Though for us, IPA is an excellent choice too.

I've also been fooled by polluted glassware!

[db]

Blimey! I wipe out my 27/3 pot with a tissue until it's clean. But then I suppose a flask is a little more awkward to access.