Hey all, Not too happy with the separation our current pens give. Was wondering if anybody can share what pens they use to obtain good separation of colours. if you could share pictures that would be very helpful! - Pens must be water soluble - Only paper (filter paper) chromatograms - Black a...
We lose quite a few felt tip pens when doing this.
I used pick up the ones pupils leave on the floor and see if they give good results.
Black, blue & purple usually give best results, but some are terrible.
Not had to buy any for years.
I do this with a range of black inks and capillary tubes for GCSE 'who done it'. (you could always fill fountain pens if you really need it to be a pen) You can buy a range of inks.
Trawled the internet for pen ink suppliers found this one that has a massive range and will supply 2.5ml samples @ about £1 a go. Got 8 different blacks to try for less than £10 including postage. Will use capillary tubes to spot the ink on the paper. The other option is to get food dyes and mix up your own combinations in water. https://www.thewritingdesk.co.uk/ink-refills/fountain-pen-ink-samples/
Here is the range of blacks
Here is the link to the thread
I am running the Edexcel CC2c1 chromatography of inks practical and need at least 4 different sets of 'black' water based inks/pens. I find it very difficult and time consuming, to get a range of water based black pens without having to buy several packs of colours from different manufacturers...