Gel coming back into Whatman gd/x 2mcg PVDF filter

[glp1user]

Curious if These filters just contain a gel in them or if my filters are fucked. For Starters let me say I know I messed up because I forgot to vent the 30ml vial I was filtering into which caused pressure build up. But after putting 5.5mls through the filter the filter back purged gelled up oil into the barrel of the syringe. Never seen this before but also never forgotten to vent the vial.

I was attempting to filter some pharma test cyp 1ml vials into 30ml jugs, to save some space and make for easy drawing. Heated the test up on a coffee mug warmer until it was warm but still easily handled (assume 140ish F as that seems the be the threshold for things feeling to hot to hold). All the vials I have yet to filter but did warm up are still liquid and not gelled, Also the test that passed through the filter and into the 30ml vial is not gelled up. Only the test that back purged into the syringe is gelled up.

I guess I should add I don't think I applied too much pressure, I have used syringe filters before and was filtering at a pretty conservative rate. took about 1.5min to get the 5.5mls through.

I'm probably an idiot that just did something wrong, but wanted to get some input. Planning on tossing the 5mls that did filter into the vial as it stands right now.

 

[TheScholarOfBrew]

Curious if These filters just contain a gel in them or if my filters are fucked. For Starters let me say I know I messed up because I forgot to vent the 30ml vial I was filtering into which caused pressure build up. But after putting 5.5mls through the filter the filter back purged gelled up oil into the barrel of the syringe. Never seen this before but also never forgotten to vent the vial.

I was attempting to filter some pharma test cyp 1ml vials into 30ml jugs, to save some space and make for easy drawing. Heated the test up on a coffee mug warmer until it was warm but still easily handled (assume 140ish F as that seems the be the threshold for things feeling to hot to hold). All the vials I have yet to filter but did warm up are still liquid and not gelled, Also the test that passed through the filter and into the 30ml vial is not gelled up. Only the test that back purged into the syringe is gelled up.

I guess I should add I don't think I applied too much pressure, I have used syringe filters before and was filtering at a pretty conservative rate. took about 1.5min to get the 5.5mls through.

I'm probably an idiot that just did something wrong, but wanted to get some input. Planning on tossing the 5mls that did filter into the vial as it stands right now.

Just for future reference, I believe the ideal filter for any of these uses would be PTFE Hydrophobic.

I'm not sure what exactly went wrong with your filter. And like you said, you didn't vent.

I suggest get a new bunch of filters and try it out again. Be on the safe side. Those whatmans should be very high quality though. I'm sorry you don't get the reply you deserve, man. A lot of people love to ignore users inquiring and gatekeeping. If I can figure out the answer for you, I'll re-reply here.

 

[Dirthand]

Did you mean to say phama 10ml vials? It would be very unnesarry to refilter pharmaceutical grade gear. Nylon or ptfe would be the filters you would want to use. I don't know what the gear you have consist of but it is possible that the solvents in the gear may have melted the membrane or the gear is crashed. those ptfe whatsman you have suck, i tried using them when I first started making gear and had to throw away quite a bit of gear that turned out cloudy.
My advice is to just leave the gear in the vials you have but if you must and just want it in 30ml vials get you some ptfe or Nylon filters. Besides the venting fuck up seems like your process I'd ok.
Peace
D

 

[TheScholarOfBrew]

Did you mean to say phama 10ml vials? It would be very unnesarry to refilter pharmaceutical grade gear. Nylon or ptfe would be the filters you would want to use. I don't know what the gear you have consist of but it is possible that the solvents in the gear may have melted the membrane or the gear is crashed. those ptfe whatsman you have suck, i tried using them when I first started making gear and had to throw away quite a bit of gear that turned out cloudy.
My advice is to just leave the gear in the vials you have but if you must and just want it in 30ml vials get you some ptfe or Nylon filters. Besides the venting fuck up seems like your process I'd ok.
Peace
D

It's surprising you say the whatmans sucks. Figured they be superior than these chinese no brand filters I have that oddly have held up to all kinds of abuse even up to 80lbs of pressure

 

[Dirthand]

It's surprising you say the whatmans sucks. Figured they be superior than these chinese no brand filters I have that oddly have held up to all kinds of abuse even up to 80lbs of pressure

Those particular ones are not good for gear... they are not rhe right membrane. What'sman is a good brand. I use cobetter.

 

[glp1user]

Did you mean to say phama 10ml vials? It would be very unnesarry to refilter pharmaceutical grade gear. Nylon or ptfe would be the filters you would want to use. I don't know what the gear you have consist of but it is possible that the solvents in the gear may have melted the membrane or the gear is crashed. those ptfe whatsman you have suck, i tried using them when I first started making gear and had to throw away quite a bit of gear that turned out cloudy.
My advice is to just leave the gear in the vials you have but if you must and just want it in 30ml vials get you some ptfe or Nylon filters. Besides the venting fuck up seems like your process I'd ok.
Peace
D

The vials are 1ml hospira's straight from the pharmacy, so it contains 200mg test C, 0.2ml BB, 9.45mg BA and 560mg cottonseed oil per ml. Vials are over filled to 1.1ml +. I was planning on putting them into a 30ml as they take up a lot of space in my medicine cabinet.

You are right they likely don't need filtering, but I thought it might be a good idea considering the amount of punctures and air exposure the needle has while drawing up a bunch of the vials into a large syringe. Ended up using some older millipore pvdf filters I had on hand and it worked flawlessly.

Now I'm just kinda of curious what is happening in the whatmans. The back purge looked like purrel, maybe ever so slightly more viscous. I did a bit of reading on the whatmans and they should contain no gel substrates within the filter and are not known to form gel complex's even in instances where the filter dissolves. I think its interesting that everything that passed through them visually looks perfect and the same viscosity as the initial inputs. And again to quell any worries, I already binned this oil and will not be using it.

My initial thought was pressure behind the back purge "whipped" the oil up as air shot back through the small holes of the filter. But I don't think that is what happened as the gel did not look very aerated or opaque/white. It was the same clarity as the oil going in. I think purrel is really the best description here.

 

[Dirthand]

The vials are 1ml hospira's straight from the pharmacy, so it contains 200mg test C, 0.2ml BB, 9.45mg BA and 560mg cottonseed oil per ml. Vials are over filled to 1.1ml +. I was planning on putting them into a 30ml as they take up a lot of space in my medicine cabinet.

You are right they likely don't need filtering, but I thought it might be a good idea considering the amount of punctures and air exposure the needle has while drawing up a bunch of the vials into a large syringe. Ended up using some older millipore pvdf filters I had on hand and it worked flawlessly.

Now I'm just kinda of curious what is happening in the whatmans. The back purge looked like purrel, maybe ever so slightly more viscous. I did a bit of reading on the whatmans and they should contain no gel substrates within the filter and are not known to form gel complex's even in instances where the filter dissolves. I think its interesting that everything that passed through them visually looks perfect and the same viscosity as the initial inputs. And again to quell any worries, I already binned this oil and will not be using it.

My initial thought was pressure behind the back purge "whipped" the oil up as air shot back through the small holes of the filter. But I don't think that is what happened as the gel did not look very aerated or opaque/white. It was the same clarity as the oil going in. I think purrel is really the best description here.

I just think it is very unessesary, but hey I'm glad it worked out!!

 

[Ghoul]

There's no gel in filters, and the PVDF doesn't melt from BA or BB exposure,

The effect I'm going to describe is only relevant because of the tiny amount you're filtering. Normally these losses from retention volume of the oil and selective retention of the Benzyl Alcohol wouldn't matter when a larger amount is involved.

You're losing 1.4ml oil to the filter, but the solute, ie, the test esters, continues to pass through, increasing the concentration of test in the filtered oil in the new vial by approx 30%. (in 5.5ml, it increases from 200mg to approx 264mg/ml.).

PVDF also selectively retains Benzyl Alcohol (it sticks to it), so you're losing some of the solvent on the way into the new vial, and, on the way back through the filter from the over pressured vial, the 30% higher concentrated oil is losing even more Benzyl Alcohol to selective retention, and your Test C is probably instantly crashing into a gel.

If you had cottonseed oil you could flush the filter before starting to prevent this, but since you don't, just make sure you filter a larger amount and stick in a vent pin to prevent backflow,

 

[glp1user]

There's no gel in filters, and the PVDF doesn't melt from BA or BB exposure,

The effect I'm going to describe is only relevant because of the tiny amount you're filtering. Normally these losses from retention volume of the oil and selective retention of the Benzyl Alcohol wouldn't matter when a larger amount is involved.

You're losing 1.4ml oil to the filter, but the solute, ie, the test esters, continues to pass through, increasing the concentration of test in the filtered oil in the new vial by approx 30%. (in 5.5ml, it increases from 200mg to approx 264mg/ml.).

PVDF also selectively retains Benzyl Alcohol (it sticks to it), so you're losing some of the solvent on the way into the new vial, and, on the way back through the filter from the over pressured vial, the 30% higher concentrated oil is losing even more Benzyl Alcohol to selective retention, and your Test C is probably instantly crashing into a gel.

If you had cottonseed oil you could flush the filter before starting to prevent this, but since you don't, just make sure you filter a larger amount and stick in a vent pin to prevent backflush.

I can't believe I used to think you were intelligent. rofl entertaining idea tho. even if it makes little to no sense.

 

[Dirthand]

I can't believe I used to think you were intelligent. rofl entertaining idea tho. even if it makes little to no sense.

What was it my old man use to say??.Dam son at least smile nod and act like you know what's going on..... if that don't work, try and bedazzle them bullshit!!
Peace
DH