Study 1
Students performed a column chromatography experiment to isolate chlorophyll from a spinach leaf extract using a silica gel column and a hexane-acetone solvent mixture.
Based on standard laboratory protocol for column chromatography, place the following procedural steps in the correct chronological order from first to last.
- 1Pack the glass column with a slurry of silica gel stationary phase and allow it to settle evenly without air bubbles.
- 2Carefully apply a concentrated sample of spinach leaf extract directly onto the top surface of the settled silica gel bed.
- 3Pour the hexane-acetone mobile phase eluent into the top reservoir and allow it to flow down through the column.
- 4Collect the separated chlorophyll fraction into a receiver flask as it elutes from the bottom drain valve.
Answer
The correct chronological sequence of steps for column chromatography is: packing the silica gel column stationary phase, loading the spinach extract sample onto the top of the bed, pouring the hexane-acetone eluent mobile phase through the column, and collecting the eluted chlorophyll a fraction.
The procedural logic of column chromatography dictates that the column must first be prepared by packing the silica gel stationary phase. Next, the mixture to be separated (spinach extract) is loaded onto the top of the bed. Then, the mobile phase (hexane-acetone eluent) is added to move and separate the compounds based on differential chemical affinity. Finally, the target separated compound (chlorophyll a) is collected as it elutes from the column exit.
Step-by-Step Solution
Key Concept
Chronological Sequence of Column Chromatography Procedures
Estimated Time:1m 30s