Chromatography Forum

Hi all,

Im thinking of investing in a good column cutter since my cutting skills with the the wafer isn't that good.

Im thinking of going for the diamond tip type, but looks kinda pricey.

Just wondering if anyone has any experience using these cutting tools with its pros and cons.

I've used ceramic wafers and a fancy (and expensive) cutter that you thread the column into and turn a wheel. The fancy one is more consistent but cannot work in confined spaces. Lots of practise with a wafer helps - the trick to to make the orignal scratch as lightly as you can, at right anlges to the length of the column, and then to pull the ends apart rather than bend at the scratch.

Anything with a pointy tip (which seems to be what you have in mind) is not likely to work as well as a sharp edge, whether that edge be ceramic or diamond.

Peter

I have used several types. The free wafers are great I did once have a Sapphire rod which looked great and worked. I hate the diamond/carbide tipped ones and found them difficult to use.

Hope the image comes out.

Peter> Thanks for the tip with the wafer. Our GCMS is still fairly new and I dont have any "unwanted column" to practice on yet, other than the one installed inside our current system.

and yes, I am kinda aiming for the fancy one that you mentioned like in the pic above.

There's also the pen type. but from the pics i see in online brochures im still wondering how do you actually use em to cut the columns.

The little ceramic wafers work fine.

Just practice w/ the wafers. Nip an inch at a time until you either get a good cut or fail 5 or 6 times, then hand off to someone with skills and have them nip an inch.

I'm right handed and I hold the column in my left hand w/ the portion to be discarded pointing toward my chest. I use a pendular motion with the right hand, holding the wafer at about a 45° angle to the top of the column, making a light cut very close to my left thumb (this helps keep things square). If the column tip does not fall away, I pull very gently, giving a slight twist. If it doesn't come off very easily, I slide my thumb back, exposing another CM of column and try again. There's a bit of a feel for getting the wafer pressure right (you should *just* be able to pick up on the texture of the wafer bouncing across the glass within the polymer coating). Once you have it, you can recreate it pretty easily.

One point that is important is that you make one pass acorss the column with the wafer. Do not try to saw through the column. If you nick the polyimide coating - the "cut" is made.

Save your money, I have that fancy one and only use the magnifier in it!
I have gotten better with the wafer over time. Save an old column to practice on.

Save your money, I have that fancy one and only use the magnifier in it!
I have gotten better with the wafer over time. Save an old column to practice on.

Hi Bigbear,
Just wondering what made you stopped using the fancy cutter?

Tarapan

Another thing to remember is that the wafers have both rough and smooth edges (which it is easy to feel). On silica columns you need to use the smooth edge.

Peter

Tarapan,

We have that fancy one and it works great. I've used the ceramic at other jobs and prefer the consistency of the diamond cutter. It also helps if you have new(er) chemists around, as everyone can make a decent cut on the first attempt. Only drawback I can think of is cost.

I gave up on the fancy one as I could not get a goood enough cut to pass endrin breakdown criteria. With some practice I now do better with the wafer ( using a smooth wafer edge).

I have a shortix capillary colunm cutter for sale, and a two upchurch scientific micro splitter valves and a lot of other items that i bought at an auctiion. email me at "cdrsavage@hotmail.com", if interested.

The little ceramic wafers work fine.

I've had these wafers for years, they work fine even though they're old and are broken on one side. I don't even use the Supelco one.

John