We had a pretty nice separation by using silica gel 60 F254 (1mm thickness) (Merck) developed twice in the same direction with a solvent mixture of chloroform:methanol:acetic acid (100:5:2) 

https://www.researchgate.net/publication/220036753_Improvement_of_a_solid_phase_extraction_method_for_analysis_of_lipid_fractions_in_muscle_foods

The same type of plates were actually working fine for further separation of PL classes:

https://www.researchgate.net/publication/220036718_Improvement_of_solid_phase_extraction_method_for_separation_of_animal_muscle_phospholipid_classes

Good luck

Article Improvement of a solid phase extraction method for analysis ...

Article Improvement of solid phase extraction method for separation ...

Merck plates are fine. Have a look at the enclosed paper. Perhaps it may help you.

Thanks for the quick answer. In fact I used a Sigma-Aldrich 60 F245 (200 micron thickness) with support in aluminium. Do you think that the brand (Merck VS Sigma-Aldrich) and the thickness could make the difference? and what about the support? I see that in your work you used the glass support. Do you think the support (glass VS aluminium) could be important for the result? 

Thank you very much

Lorenzo

I have the feeling that it shouldn't make any difference (neither glass, nor the brand). At least not to the point to have no separation at all. The thickness could make a difference in separation, but again, my feeling is that, if everything is OK, at least you should see some migration. Could they be out of date? Did you activate them? Sometimes, if they were not properly sealed, they can adsorb quite some water, and it is difficult to have any migration. You can try to pre-elute the plates with methanol and dry them thereafter with methanol above 100C. Have you check the solvents and a proper saturation of the chamber?

Beautiful plates Begoña, by the way

I have used silver nitrate silica gel for column chromatography to spate triglycerides. Silver ions do contribute in selective retention of unsaturated fatty acids and their triglycerides, I have achieved greater separation of mono and poly unsaturated FA and TAGs. I'm sure there are silver nitrate silica gel TLC plates or a simple method to impregnate silver nitrate to existing silica gel plates.  

silica gel thin layer plates (TLC) G-60 Merck

Silica Gel 60 G (Merck) if you are going to burn it for optical read

If you are going to read it with Camag or similar it could be useful Silica gel 60G F₂₅₄

We also use Silica Gel 60 from different commercial sources (Merck, Fluka) to separate lipid classes. We prefer developer systems based on petroleum ether, diethyl ether, and acetic acid. A typical proportion would be 80:20:1 (v/v/v), but you may experiment by changing the proportions of the former two to get an ideal separation of your components. 

I use silicagel plates Whatmann LK6DF, they have concentration zones (cellulose) and separate rows on the same plate, giving very good separation for different samples in parrallel.  They are nonetheless quite expensive. 

In my experience,  thin layer plates with silica gel on glass plates are more easy to handle, reveal and scrappe than aluminium sheet

Thank you to everyone for the extremely useful answers. Despite I followed your advices regarding the plates, my lipids still do not migrate. I tried only with the standards, I checked that I am using the right diluent, I verified that the plate is the right one (60 A siilca gel sigma aldrich f254 on aluminium support), I tried pre treating the plate with methanol, I tried activating (100 ºC for 20 minutes) ad not activating the plate, I am using a chamber that is properly sealed so that the environment should be saturated, I follow a very simple protocol that is easily found in several publication....but despite all these things...the spot of the standard remain at the starting line and do not migrate...anything, not 1 mm moving up....I thought TLC was one of the simplest techniques, so I guess that there is something very basic and very stupid I am missing. If anyone of you can have an idea on why lipids does not absolutely migrate it will be a big help.

thanks

Lorenzo

I have no experience at all with wax esters, but I know that they are very difficult to handle with current solvents,  perhaps are they interfering with the separation of your other lipids on TLC. You might find an answer by asking to people working with plant lipids. Many years ago there was in Grenoble a lab directed by Roland Douce (He his probably retired now) which has a great experience with plant lipids . Perhaps could you try to find some answers in Grenoble or in a lab from INRA .

CEA Grenoble

Laboratoire de physiologie cellulaire et végétale

équipe de biogenèse et homéostasie des lipides membranaires

Direction Eric Maréchal tel 04 38 78 49 85

In my works total lipids were analyzed by thin-layer chromatography (TLC) on Silica gel 60 G of 0.25mm. TLC on glass plates were developed using as solvent systems, n-hexane/diethyl ether/formic acid (80:20:2 v/v) for non-polar lipid. Silica gel G developed with hexane-ether-acetic acid (60:40:1) also gives satisfactory separations of most neutral lipid classes. Moisture content of the adsorbent is an important parameter which determines the mobility of the lipids to a great extent. When the water content  is small the lipids migrate slowly and vice versa.The moisture content in turn is influenced by the activation, sorage, and quite significantly, by weather conditions. Solutions of lipids en chlorofom (chloroform-methanol 9:1, or chloroform-methanol 2:1) are satisfactory for spotting.

Total lipids were analyzed by thin-layer chromatography (TLC) with Silica gel 60 G (Merck) of 0.25mm on glass plates. 

We activate silica gel plates on glass support at 160C.  We leave 250micron plates at that temperature for a minimum of 30 minutes and 1mm plates I would leave for 90 minutes.  It might be worth a try.

I bought glass plates silica gel 60 F524 For analysis of herbal materials, but both the analytical markers and sample spots are too dim compared to the TLC aluminum sheets I used for optimizing the solvent systems...how can I make the glass plates spots more clear ( without increasing the concentration of analytes)?