TLC climbing problem! Please help. . .
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I am now using microwave synthesis to synthesize an organic substance, which is a purple-red substance. In order to separate this organic matter, I had to use TLC climbing plate (other methods cannot be used because it is not clear what the substance is). After working for a long time, it was not separated. The polarity of the developing agent is probably close to that of diethyl ether, but because I ordered too much sample, it caused tailing. Continue from the sampling point to the top. When using ethanol, the polarity is too high and it goes to the top. I did it again yesterday, using ether: n-hexane: Acetic acid=5: 1: 0.2 The result is okay, but my sample size is still too large. This caused tailing and was repeated a few times today. The amount of developing agent remained the same, but the amount of spotting was smaller and smaller. But it actually stayed at the same spot and didn't move at all. What is the reason? Did I order too little? In addition, when my organic substance is dissolved in ethanol, it will be red when the amount is small, pink when the amount is more, purple when the amount is more, and purple when the amount is more concentrated. What is the reason for this? If you order samples, how many dots and which color are more appropriate?
1. When using TLC for separation, try not to adjust too much. For the concentration, you can dilute the sample in a planned way, dilute the original sample 100, 50, or 10 times, and use the clamping method to find the appropriate concentration range. 2. When selecting the developing agent, please follow the same principle. 3. The correspondence between the depth of the color and the concentration is established. A good example is that when the concentration of potassium permanganate solution is different, the colors reacted are different.