29. Chromatography with solid stationary phase is called

• (A) Circle chromatography
• (B) Square chromatography
• (C) Solid chromatography

• Chromatography with solid stationary phase is called adsorption chromatography. The correct answer is option (D).

  Question Breakdown

  This MCQ tests basic chromatography classification by stationary phase type, fundamental for GATE Life Sciences biochemistry section.

  Option Analysis

  • (A) Circle chromatography: Incorrect. No such standard chromatography type exists; likely distractor term.

  • (B) Square chromatography: Incorrect. Non-existent terminology in analytical chemistry.

  • (C) Solid chromatography: Incorrect. Generic term; doesn’t specify separation mechanism (adsorption vs partition).

  • (D) Adsorption chromatography: Correct. Uses solid adsorbent (silica, alumina) as stationary phase where solutes bind via surface adsorption (van der Waals, H-bonding).(D) Adsorption chromatography

  Introduction
  Chromatography with solid stationary phase is called adsorption chromatography, where silica gel or alumina adsorbs solutes via surface interactions while liquid/gas mobile phase elutes them differentially. This distinguishes it from partition chromatography (liquid stationary phase) and powers early separation techniques in biochemistry research and GATE Life Sciences exams.

  Adsorption Mechanism

  Solid stationary phase (adsorbent) provides high surface area for reversible solute binding. More strongly adsorbed compounds move slower through column.

  Key Adsorbents:

  • Silica gel (polar, acidic)

  • Alumina (polar, adjustable pH)

  • Carbon (non-polar)

  Mobile Phases: Hexane → increasingly polar solvents.

  Types Comparison

  Stationary Phase	Chromatography Type	Separation Basis
  Solid adsorbent	Adsorption	Surface binding
  Liquid coated on solid	Partition	Solubility partitioning
  Ion exchange resin	Ion exchange	Charge interactions

  Applications

  • Natural product isolation (Tswett’s chlorophyll separation)

  • Preparative purification

  • TLC/HPTLC stationary phase

  Used when samples have wide polarity range; gradient elution enhances resolution.