Australia's Science Forum

Hello fellow labbies!

I recently became the lab manager at Townsville Grammar and happened upon this forum as I was looking for helpful resources. I already found answers to many of my questions just by browsing the forum (thank you all for that!) but I have a couple of specific questions that I wanted to ask:

What solvent do you use for a plant (spinach, in my case) paper chromatography prac?

I'm currently running with a 9:1 hexane:acetone solution that seems to work fairly well, but I'm curious if this is standard across the board or if anyone has played around with different solvents to get optimal results.

As a supplemental question:

Are there other leaves (besides spinach) that you have found produce better results for this prac?

TIA for your help, and I hope I can be of assistance to some of you in the future

We use methylated spirits and any soft leaves - so pinch stuff from the garden. I'm not sure of the method, but I do know they have to heat it first - usually a water bath set up. Sorry, can't help any more!

Merilyn1 wrote: ↑01 Mar 2021, 06:50 We use methylated spirits and any soft leaves - so pinch stuff from the garden. I'm not sure of the method, but I do know they have to heat it first - usually a water bath set up. Sorry, can't help any more!

That's what we use here too Merilyn .
The Chlorophyll is extracted from the leaves by placing the leaves in Metho and heating in a water-bath . ( Small beaker inside larger beaker of boiling water usually heated on a hot plate for safety reasons )

Then about a cm of Metho is placed in a test-tube and a dot of extracted chlorophyll is placed on a strip of chromatography paper ( just above the height of the Metho in the test tube) and placed in a test tube .

Yeah, I should remember that. Did it at uni, but that was in 1990-something! I guess I'm excused for forgetting

Thanks for the responses. Methylated spirits would certainly be a more cost effective solvent. Do you get good banding of the pigments with it? We typically use acetone for the extraction followed by the hexane:acetone solvent for the mobile phase, but I might try the spirits for the solvent and see if it gives similar results.

Cheers!

We mostly do it as a junior (year8 I think) prac so they care little about the outcome . Certainly wouldn't be allowed to use Hexane as it has always been Year 11-12 only . Incidentally , Hexane is teacher only now on Riskaccess .

I am curious what sort of improvement your method gets though .Could be a good teacher demo .

Ah, I see, this is for year 11 bio classes. Good catch on the hexane in RiskAssess, I should have been more specific in that I'm using Cyclohexane, which is in the Yr 11-12 users.

I'm not sure if they'll do chromatography in junior science (I just started the job a few weeks ago). If so I'll certainly try methylated spirits, or possibly just straight acetone. I have some leftover spinach from the pracs last week so I might just run a few tests with these different solvents and see what shakes out. I'll let you know if I get the time to do a proper test.