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Long-term RC storage

atara said:
Nitrogen is cheaper and just as good, unless you're welding titanium or chromium, which form nitrides. None of us are welding, though, I think.

You might want argon if you're trying to preserve one of those nitrogenase enzymes all life on Earth depends on, but that's pretty niche.
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Argon is trivial to obtain though and heavier than air, which would presumably make it more effective and simpler to use.
 
Being heavier than air it presumably then would displace the oxygen in the storage vials by "pouring" it into/over the mouth of the vial. I also presume that the gas is maintained in pressurized containers (or at least what I have found is). So how do you pour/drip/whatever a pressurized gas? Would this require some piece(s) of specialized lab equipment?

Please be patient with me - I barely passed high school chemistry.
 
High school chemistry??? You are doing better than I. I thought that chemistry was between a man and a woman.

If the argon is heavier than air, I wonder if you could simply shoot it (I assume it is under pressure) into a drinking glass, or something with a spout, and it would simply sit there (in the absence of air currents) until you decided to pour it into the little containers. I assume it is invisible, so there may be a little bit of faith involved with this method. Also it will look really funny if someone sees you pouring an empty glass into a test tube.

Of course, it may be better to put some plastic wrap or something over the top of the glass and use a straw or rubber hose to direct the flow as you "pour" it from the glass.

I assume that the argon is safe to keep bottled up for long periods with something you are going to put into your body one day.
 
enthogenist said:
So how do you pour/drip/whatever a pressurized gas? Would this require some piece(s) of specialized lab equipment?
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I was thinking along the lines of a lightly pressurised glovebox type workspace to fill vials/bottles in, supplied straight from the regulator output so the gas flows in at the base then out of the top, like an overflowing bath.
 
That is pretty fancy, but if you have the equipment, the patience, and the undisturbed space to attempt this, then it sounds fool-proof.

I was thinking more along the lines of measuring out a bunch of 1g vials (say, 50 or so), and placing them all into a deep container of some sort - something about a foot deep - like a large plastic pitcher for making tea, or maybe a milk jug with the top cut out. The vials would be placed close together at the bottom, and a fairly large quantity (i.e. 2 or 3 milk jugs full) of argon would be poured into this container directly onto the vials. Pouring lots of gas is the only way I can think of to force the oxygen out of the vials. Then you would reach in and place the tops on each vial before lifting it out for storage.

From Universal Gas Industries: "Argon gas is colorless, odorless and non-flammable. It is non-toxic. The primary health hazard is asphyxiation by displacement of oxygen."

If the above is true, then I guess you could test whether you actually have argon in the vat of vials by putting a match in it.

Better yet, it might be better to fill your vat of vials with gas while the vials are all empty, then reaching in and filling them up while holding them well below the top of the vat. Then capping them up and removing for storage. This migth also keep you from knocking over vials when you reach in to grab them. This might have the same effect as the pressurized glovebox mentioned above.
 
Oh hell yeah.......I just placed my order. $39 is a small price to pay (with free shipping) to protect a $3K investment. This beats the argon bath approach anyday.

The only think I am worried about is the velocity that the gas comes out of the tube. But I am sure I can work around that. I may do a combination of the argon bath described above, and then use this little jewel to ensure that all the oxygen is out of the vial before sealing.

Have you found any good vials that would hold about 1g each that would give a good, foolproof seal? I was considering the amber vials with the screw on lid, but I would rather find vials that had rubber (or silicon) stoppers that had to be forced down the neck to make the seal.
 
laboratory parafilm is great for placing between a vial and its lid to ensure an inert plastic seal.

also, i know of at least one glass bottle vendor that offers conical poly-seal lined caps.

o.O you're putting $3k into research drugs and will be storing them all? do you know something about a coming apocalypse that i don't?

*rushes out to buy bottled water and cigarettes*
 
I've chosen to go with the square-sided clear vials. These appear to hold about 1.25 -1.5 grams filled close to the top. The caps have a fairly good plastic covered insert, but I'm also going to wrap the threads of each vial with teflon tape.

My plan is to use a rectangular plastic box (Beanie Baby-type display case) 4"x4"x7.5" that opens at the end for the "gas chamber". I'll set the filled vials side-by-side so there's no movement and brace them in where necessary (I guesstimate that the chamber will hold around 25 vials and my supply is vastly smaller than even that). Fill the chamber with gas - each cartridge is claimed to do 18 one-inch wine bottle sized layers of gas so there should be more than enough. Then using a dowel rod (or even a pencil) - with a dab of double-sided foam-type tape - stick each cap to the rod and carefully lower the cap down to the top of each bottle through the gas. With the square-sided bottles holding firm in the bottom of the chamber I should be able to put enough torque on the caps to get them mildly tight.

At least - that's the plan.

One of the dandy things I see about this dispenser is that with the regulated flow I should be able to handily "top off" the individual vial in use for recapping and placing back in storage.

And as you said - at that price - hell yes.
 
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The problem with those devices is that they have proprietary fittings, the flow rate generally isn't adjustable, and the gas is ridiculously expensive. There's less than 4 liters in a cartridge. They do look convenient though for occasional use.

A 110liter disposable cylinder of welding argon and a basic regulator costs around $45 USD.

If you pack vials in normal air then cap them in an inert atmosphere, there will probably still be air + moisture trapped between the particles of powder/crystals, also:

...One of the dandy things I see about this dispenser is that with the regulated flow I should be able to handily "top off" the individual vial in use for recapping
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I can imagine this potentially ending up with a cloud of dust and an empty bottle :D be careful!
 
Ceres said:
The problem with those devices is that they have proprietary fittings, the flow rate generally isn't adjustable, and the gas is ridiculously expensive. There's less than 4 liters in a cartridge. They do look convenient though for occasional use.

A 110liter disposable cylinder of welding argon and a basic regulator costs around $45 USD.

If you pack vials in normal air then cap them in an inert atmosphere, there will probably still be air + moisture trapped between the particles of powder/crystals, also:



I can imagine this potentially ending up with a cloud of dust and an empty bottle :D be careful!
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Thank you Ceres - that's why I started this thread over here. I don't know what I'm doing and I am hoping the experts will give some sound advice.

The descriptions by the reviewers made it sound as though the gas flow from this gizmo was rather slow - but I could be wrong.

If/when I find one of the tanks/regulators you are referencing for that price (which I haven't yet but I'll keep trying) - and fill my described "chamber" from the bottom and then place the supply in the individual vials...if I am able to get this thing set up as described - does this approximate the "glovebox" type of workspace you mentioned before?

Thanks for the valuable insight.
 
Where did you find the square vials with plastic insert caps? I've looked, and all I've see that are 5/8 dram or so were round.

I am finding lots of sites that sell 5/8 dram vials. The standard crack vial seems to be a dime a dozen, but I don't think they will stay air-tight for extremely long times. One interesting thing that I hadn't seen before was Polyseal cone lined caps as mentioned by greeniemeany earlier (what a wonderful modern age we live in). You can find them everywhere. Just search for "Clear Dram Vial with Cone Lined Cap".

Intrinsically though, I just feel that caps that grip both the outside and the inside of the neck would be best.

Another type of lid that looked appealing was from a UK site (but I'm sure there are lots in the US too) that were the types of stoppers found in injection vials. A press-on stopper that gripped the neck securely that would not shrink when frozen for a long time might provide the best seal. See link below:

http://www.ls-uk.com/injectionvials2.htm

If anyone has any negative experience with either of these, I would like to know it.
 
Greeny: I don't know of any apocalypse, but I am old enough to remember when LSD went illegal as well as Ecstasy, and I remember when pot came in a Prince Albert can, filled to the lid (and was called a "lid") - and cops would pour it out if they caught you with it rather than run you in. Once it is gone, it ain't comming back - except by bathtub bootleggers or nasty labs fueled by Mexican blood money. Right now, the shit is pharmaceutical (even if they are mosty Chinese), and there is little incentive to cut it, and Fed-Ex will bring it to your door, so get it while you can.

Of course, I would love nothing more than for my investment to become worthless because of the sudden legalization of MJ, but I ain't holding my breath.
 
They appear to be not so much plastic inserts in the caps as a plastic coated insert. The actual insert backing may be cardboard for all I know - but they are what they are and will be what I use. I found them at a health food/supplement store - along with the 15ml and 50ml amber bottles with a plastic cone insert that I use to store the small amounts of ethanol solution I prepare for soaking the herbal blend. I also find that the smaller amber bottles each hold about 3.5 grams of treated herb - which when you're making 1/4 oz batches handily will fit in two of these - and also make discreet and non-descript containers for the blend.

I wish that the vials had a similar cone-type insert, but I'm counting more on the teflon tape to hold the seal. I've found this tape will effectively contain water pressure - even at extreme temperatures - so I'm hoping it will contain the non-pressurized argon as well. The vials may not be ideal - but they're what I've found and they were cheap. As my budget is quite limited, cost remains a factor in every aspect of this project.

The shape of the vials is my main concern now - mainly to insure firmly positioning the vials in the chamber as I carefully move the small funnel (likely with the help of a set of small needle-nosed pliers) from vial to vial as they sit in the argon bath. I'll probably add a few puffs of gas after each vial fill to replace the argon that will surely spill out of the chamber as I move the funnel. Luckily the funnel sits securely in the mouth of each vial at the perfect height so I can determine when the vials are filled near the top.

We seem to be in rather unchartered territory here so most of what I'll be doing continues to be pure guess-work.
 
It's not really unchartered territory, since sample preservation is important to so many areas of chemistry and biology... there's a lot of literature on the subject.

I just use neutral glass tubular vials that have phenolic plastic screwcaps with teflon faced rubber liners. The seal is airtight and they're easy to sterilise.
 
how long do you think alpha-methyltryptamine would last before it loses its potency? i have half a gram just sitting in a drawer.
 
I would be very careful in putting the pressurized argon tube that close to the mouth of the vials (i.e. using needle nose pliers). Even if you can regulate it, it still runs the risk of the "puff of powder" mentioned above. You might consider testing first with baby powder.

You might also consider putting a home-made diffuser over the end. Maybe something like small strips of a handkerchief or even something like fine steel wool - you could wrap it round the end of the tube and secure it with rubber bands. Anything to keep the flow of gas from putting all its force in the direction of the mouth of the vial.

The process of filling the vial will be aided by the fact that argon is heavier than air, so I am going on the premise that shooting it into the container will not be required to displace the oxygen - merely holding it a coule of inches above and letting it sink, or drip into the vials might be sufficient.

Does anyone know, in practical terms, how much heavier than air the argon is? I don't know if its atomic weight is of much help. I was wondering if anyone knew if it slowly drifts down under the force of gravity, or does it fall like water being poured out of a glass? That might also give us an idea how much we need to concern ourselves with standard room air currents blowing the argon out of the glovebox or the large "vat of vials" (whichever you prefer).
 
Jwndy said:
I
Does anyone know, in practical terms, how much heavier than air the argon is? I don't know if its atomic weight is of much help. I was wondering if anyone knew if it slowly drifts down under the force of gravity, or does it fall like water being poured out of a glass? That might also give us an idea how much we need to concern ourselves with standard room air currents blowing the argon out of the glovebox or the large "vat of vials" (whichever you prefer).
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Think about what happens when you pour milk into a glass of water, and how difficult it would be to acheive two seperate layers....
 
I read somewhere that argon is roughly 25% heavier. The dispenser is said to give a one-inch layer of gas with 5-6 one-second "puffs". That should provide a similar level of coverage in my filling chamber. I think the best I can do is to keep "puffing" the argon over the top of the chamber as I proceed with filling/capping the vials and hope the constant presence of the heavier gas will gradually make the oxygen to rise out of the vials - or at least to minimize its presence as much as possible.

I totally agree that placing the tip of the dispenser near the mouth of a filled vial would be inviting trouble. After testing the force of the individual "puff" I'll have a much better idea of how/if to handle the "topping off" issue.

Primarily, I tend to see this dispensing device as a kind of manual regulator for the initial filling process. I know the relative cost of the argon by "cartridge" is ridiculous - but I need so little that even the possible cost of additional cartridges isn't much of a concern. I honestly think just one cartridge will complete the entire filling process. Should I need to replace argon cylinders - I'll just slip the cover on the chamber. In fact, after the initial argon fill it would seem to be a good idea to let the undisturbed covered chamber sit for a bit to give the oxygen a chance to rise before proceeding with the process. The funnel would not be pulled up out of the chamber until all the vials are filled and capped. The only thing that would go into the chamber to displace the argon will be the tip of the needle nose to move the funnel from vial to vial - the powder itself being dumped into the funnel - and the tip of the dpwel rod to capture and apply each vial cap (caps to be left in the chamber on their side before puffing in the argon). If - in a reasonably controlled working environment (no air drafts and slow/careful/economical manual manipulation of the tools) - if every minute or two I then keep gently puffing argon over the top of the vial holding chamber as I complete the process...this would seem to, in theory anyway, appear to have the promise of working as well as this poor amateur can hope for.
 
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