In tlc lab when you separated spinach pigments’, in previous years most sections found 45: 55 acetone: hexanes mobile phase composition to give the best results. in column chromatography, the best mobile phase turned out to be 40: 60 or 35: 65 acetone: hexanes. what is the reason that the exact mobile phase composition from tlc does not give the best separation in column chromatography? explain (4 pts)