Pipetting 100 Microliters Onto A Swab

[lapis]

I am occasionally asked how (and maybe why?) I use a swab with 100 microliters of ink on it (e.g. http://www.fountainp...anc-ink-of-joy/, thanks, Blizzard). It goes like this:

 

I use a 200-microliter adjustable-volume medical-science pipette from the company of Gilson (made in France) but those of the company Eppendorf are -- at least here -- much more common. Eppendorf is a medical company situated in Eppendorf, a district in Hamburg. I prefer Gilson pipettes because they fit much better in my hand.

 

Sure, they are expensive, but... psst... I pinched all of mine from the lab...

 

... Gilson pipettes having this and similar sizes come in at $280.00 each.

 

The reason I use these for a swab is simply to make sure that, for comparisons, each swab for each ink gets exactly the same amount of ink on it. Otherwise there may be differing thicknesses and absorptions on paper.

 

Sorry to those of you who already know all about this. But apparently some don't so here's a shot or two. 

 

Plastic tips are -- like the swabs -- of course consumable goods. The M800 is for a size comparison. I always use a small tray for this, but you can do everything in the sink, too.

  

This model can be adjusted (manually) to deliver between 0 and 200 microliters.

  

Tuned in to 100 microliters of ink, here we go!

 

Voilà ! (or, as this posting once said, "put that in yer pipe an' smoke it"

 

Of course you don't have to do it "my way", you can also just use one drop from any pipette (a "drop" is usually about 1/20th of a ml, i.e. about 50 microliters). Anywhere between 50 and 200 microliters always seems to do the trick for me.

 

Whew

[stevlight]

I was just watching the show "CSI" and seeing them use these thought "These would be great for mixing ink". I think now though that they do not hold enough ink for mixing...............and they are very expensive!

[MCWB]

I was just watching the show "CSI" and seeing them use these thought "These would be great for mixing ink". I think now though that they do not hold enough ink for mixing...............and they are very expensive!

They sure are expensive, but you can certainly get such pipettes and tips in 1mL, 5 mL and 10 mL (that's the biggest I've used anyway) which should enable quite accurate and reproducible colour mixing. Then of course you need to put some in a cuvette and whack it in your handy spectrophotometer.

[Token]

Oh phew.

 

I thought I was crazy.

 

I've bought 3 pipettes [yes, not "borrowed" from a lab], just so I can mix and measure my inks correctly. I try and justify it to myself by saying things like "i'm being more precise" and "think of all the ink I'm saving by not measuring out my mixes in drops".

 

But really, its just part of the fun.

 

 

 

I just bought one recently: a Rainin EDP-2 250uL electronic pipette. I wanted that because I had a gap in volume with my current 200-1000uL Labsystems Finnpipette, and my Wheaton/Socorex 5-50uL 8-channel pipette.

 

I've now spent far too much money on pipettes, and not enough on ink [and pens]...

I really wish i had a spectrophotometer, but I cant justify spending that much...

 

In addition, i think I've found an interesting way to apply ink to paper- i put a drop of [non-standardised-yet] volume on a piece of paper, then spread it out in one direction with a credit card. I haven't really put much effort into testing that, however it seems to be pretty repeatable.

 

EDIT: Lapis, how do you ensure that each swab has almost the same volume? Wouldn't that affect the amount of ink that would be available for transfer to the paper?

 

 

 

But, on the topic of precision ink measuring, do you have any other handy hints you could share?

Edited August 8, 2011 by Token

[Blizzard42]

Thanks lapis for explaining here.

I couldn't snatch one off work because they are all registred in our systems since we have a yearly calibration and certification contract with Eppendorf and since we haven't got that many it would sure be missed. I wouldn't even think of snatching it, since it's so contaminated I would probably fear of putting myself into danger.

I like the idea but I still think there are too many errors like how often you stay in one place with the swab, the pressure and how often you go over the same place. Token's idea with the credit card is a good step forward, but still not perfect. Also I think it may be hard to clean the credit card afterwards and using it again.

 

How do you think would you benefit from a spectrophotometer for mixing inks? The only use I could think of would be the possibility to verify the right mixture. Although, I'd prefer a liquid colorimeter (LICO) in this case. It could accurately show the color in the L*a*b* gammut.

Edited August 8, 2011 by Blizzard42

[Token]

Yeah, I was thinking if it were possible to look at the absorbency of the inks, you could try and find inks that allowed you to mix inks with a large gamut. At the moment, its trial and error.

[Chris]

You certainly don't need the extreme precision of an Eppendorf/Gilson when mixing inks. Something like an ordinary graduated pipette would do and I am sure you can buy them through the internet. They are a bit fiddly to use if you have not been taught how to do so, but if you can drive a car or write your name, you can certainly master a pipette

 

Chris

[radellaf]

What you need would depend on what the smallest volume of ink-mix you want to make is going to be. A common 3 or 5ml syringe is good to at least .5ml, enough for a 5:1 mix even just in the syringe. If you want to mix a batch just big enough to fit in a int'l converter at a 10:1 ratio then, yeah, you'll need better resolution.

[lapis]

You guys seem to have thought a lot about this task as well! Lemmee just add a few lines as re what I myself find here:

 

(1) Yes, I think you can find any ol' "ordinary" pipettes anywhere. As said above, in 1, 2, 5, 10-ml versions. Often plastic (like PVC or more resistant PVP) but glass is even better if you want to wash the things out with water. Glass pipettes usually have fractions like 1 to 9 on them for a 10-ml job. Simple 1-ml insulin syringes might be the best way to start.

(2) Basically, I'd say that you never really have to use a pipette for mixing inks. Just use a few drops first to save ink if you don't like the colour resulting. If you really like a 5-drop to 5-drop mix, then you can always take two or more whole 10 or 15-ml Nalgene bottles and fill each one up with each ink. Using a whole 30 or 60-ml bottle which the ink was bought in would be a waste.

(3) How do I ensure that each swab has almost the same volume? First, you need of course identical swabs. Secondly, I hold the swab facing down at an angle of 45° (very roughly of course), let the tip of the pipette tip soak into the bottom of the swab, getting absorbed and then slowly and gently empty the ink into it. You don't have to practise here like on a guitar, just make 2-3-4 swabs with one ink or different inks, draw them over the paper all with the same pressure and angle, and it otta look good!

(4) How do I think I would benefit from a spectrophotometer for mixing inks? Hardly! That's all much too complicated. I just use my eyes. If they don't like the mix, I don't keep the mix. To verify the "right mixture" you'd certainly have to have a perfect, indistinguishable vision in mind, like working out a perfect Burgundy (tough luck we can't turn inks into real wines...). Richard had this in mind as he got Diamine to cultivate his Syrah. But even then, a spectrophotometer won't really do the trick. All that can do is record the wavelength's peak maximum for a qualitative assessment (too much red? too much blue?) and the AUC for quantitative measures. You'd need a form of chromatography for this, like TLC, HPLC etc etc.

(5) Last but most, it's the fun of it all!

 

Mike

[tinta]

I'm just an old pen user & new to the many activities described on these pages. I understand that the medical pipette will give you a consistent amount of ink. But, could you please explain what the swab is used for?

tinta

[macaddicted]

I was just watching the show "CSI" and seeing them use these thought "These would be great for mixing ink". I think now though that they do not hold enough ink for mixing...............and they are very expensive!

They sure are expensive, but you can certainly get such pipettes and tips in 1mL, 5 mL and 10 mL (that's the biggest I've used anyway) which should enable quite accurate and reproducible colour mixing. Then of course you need to put some in a cuvette and whack it in your handy spectrophotometer.

 

Can we just do chromatography? Paper towels are cheap.

[radellaf]

What are they for? Showing an ink's color more consistently than filling in an area with a pen.

Common in reviews here and... http://www.gouletpens.com/Swab_Shop_s/793.htm

[tinta]

I have read some ink reviews last night and a number of times the term "swabbed the ink" was used. What does all this mean? tinta

[Blizzard42]

I have read some ink reviews last night and a number of times the term "swabbed the ink" was used. What does all this mean? tinta

 

 

Well, those things you see in the first post that are usually being used to clean ears, those are called swabs. If you take a piece of paper, soak the swab end in ink and then apply it to the sheet, that means "swab out".

[lapis]

Tinta, one way to look at it is like this: A "good", actually "normal" way of showing us all what one of your inks looks like would be to use a pen with that ink, on paper. But... the looks of that ink on paper will depend very much on the pen used. I.e. on its flow rate and on the type of nib in it...

Sooo.... using a swab often offers a few advantages: Iti is "independent" of any flow and nib, it doesn't necessitate a lot of scribbling, and... it saves you any amount of cleaning and drying the pen before using it to look at another ink.

The use of any "real" pen (be it a FP or a dip pen) is certainly more revealing, but costs a lot more work.

 

Mike

[tinta]

Thank you for your explanation, Mike!

Is the use of "the swab" something that ink collectors do?

The FPN has opened up to me, some fascinating aspects around the use of fountain pens. For many years I've only used one good German pen, & one good bottle & colour of ink, (until the bottle was empty, or the pen broke).

Now, I can imagine myself owning two or three pens & a few different inks.

This could become very dangerous!!

Cheers: Istvan (tinta)

Edited August 10, 2011 by tinta

[Chevalier]

I only used bottles with medical dropper plug. I measure 2 drops on a glass plate and suck it up with a swab, this should be accurate enough. Even letting a swab suck ink for the same amount of time should be enough. Everything else sounds overkill to me, you'd need a robot to reap benefit from anything more acurate.

[lapis]

That's a possibility to generate and/or use a certain volume for analysis, although  2 to 5 ml is unusual for most cuvette sample volumes. Also the price is too high for one single size (in contrast to a pipette like that shown up top in this post which is adjustable from 0-20, 0-100 or 0-200 ml). The biggest problem with a cuvette of any size is it's inability to offer any certain volume for re-use. Getting any solution (e.g. an ink) in is okay, but getting that out to place it onto a chromatography strip is IMO too difficult or even impossible.

[bunnspecial]

On 8/8/2011 at 4:51 PM, macaddicted said:

 

Can we just do chromatography? Paper towels are cheap.

 

I realize I'm replying to an ancient post, but chromatography isn't necessarily cheap

 

Quote I received last week...and am hoping I'll get the money to buy(but not guaranteed). And no, this isn't for ink(although I can't promise some wouldn't find its way in there) and also lacks a lot of the consumables needed.

 

 

And one not so suitable for ink analysis that I do think I'm likely to be able to buy...

 

 

[lapis]

Thanks for that post. I've often thought that the best occupation I could ever have had was spending all day, every day (often nights, too) in my lab. As a huge support for my interest in inks, that is. Sure miss that since retirement. 😢