Chromatography Forum

Hi all,

There will be algae growth when I put pure water in mobile phase bottle, even it is a brown bottle.

How about with 0.1% acid (e.g. formic acid, TFA...or others?) in it?

There will be vendors of premixed acid-containing water that specify shelf lives much longer than their pure HPLC water.

Given the low cost, most analysts will probably toss the premixed aqueous mobile phases every few months ( for TFA ), or sooner ( for higher pH acidic modifiers - eg formic, acetic ). Why take the chance?.

Bruce Hamilton

It is absolutely impossible for algae to form in PURE water.
Acetate at pH of 6 or above is quite good in allowing microbe formation.

I once had something biological in a bottle of D2O - I am not sure that this was algae, but it was certainly something i didn't like in my mobile phase container.

Alex

[It is absolutely impossible for algae to form in PURE water. ]

I don't know... I have seen the spontaneous formation of life in what I thought to be a carbonless environment...

Hans is right, nothing can grow in pure water, but exposing water to the air introduces enough carbon dioxide for a little to ecosystem to get started.

Peter

I said "pure HPLC water" - meaning without TFA - sorry if that was not clear.

Anyone who has operated a "purified water" or "Water for Injection " plant in a pharmaceutical production environment will know how difficult it is to keep the system sterile and free of biofilm.

Wildlife will freely grow in most waters that are not kept sterile, especially HPLC bottled water, eg Merck LiChrosolv, which specifies =<25CFU/g, and =< 5mg/L residue - and it's all downhill after opening in a normal analytical laboratory .

Bruce Hamilton

Gee, and I thought Uwe and others saw some cold nuclear fusion, oops, some cold fission would be necessary also (H2O >> C + O and:
O >> C + neutrons which the above carbon picks up, etc., then some chemistry: C + H2O + N2 >>> amino acid).

Seriously, though, it´s dust that causes much of theses microbe problems. In water purification system the resins (ion exchangers) provide organics, that´s why some water purification systems use elaborate methods to remove these.
One needs to learn how to reduce the dust problem, it should be possible to keep an opened bottle of "pure" water for half a year or longer, depending on how often you open it.

will be algae growth when I put pure water in mobile phase bottle ... acid in it?

Yes, you will get stuff growning in it.

I had a had time convincing my colleagues of this. Some wise person on this board recommended opening a bottle and leaving it out for a while to culture some fuzzy to show them. It only took about a ~7 days to get good swirly clumps.

Also, you can get some microbes that actually prefer a little acid. So, say for example you have a bunch of fermentation samples comming in, but they are badly infected with bacteria... bacterial that happily keeps growing at 3% lactic acid... You KNOW you have the microbes floating aroudn the enviroment just waiting for the chance to "accidentally" inncoculate your water.