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1.) Explain why adding acetic acid to your developing solution during chromatography tends to eliminate "steaks"...

1.) Explain why adding acetic acid to your developing solution during chromatography tends to eliminate "steaks" on the TLC plate that are frequently observed in non-acidified solutions.

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Expert Solution

When a developing liquid is added to the compound spotted, it moves up the plate due to the capillary action. The compound spotted on the plate moves up along with the developing liquid and the distance they travel depends upon the polarity of the substances. When compared between two substances of different polarity, the one with lesser polarity proceeds further than the one with more polarity. When the liquid phase or developing solvent is more polar then it gets more attracted towards the solid phase and poses trouble in moving upwards causing excess spotting of initial material. Thus, if the developing solvent is more polar,it may lead to excess spotting of initial material along with the developing solvent leading to 'Streaking'. When few drops of acetic acid is added to the developing solvent to increase its polarity to a greater extent. This reduces the interaction of the developing solution and the solid phase.

queen_honey_blossom answered 2 years ago
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