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UPSC Combined Geo-Scientist

Chemist

  • 3 descriptive papers
  • 200 marks each
  • 3 h per paper

Mains Paper III covers analytical and organic chemistry.

UPSC Combined Geo-Scientist, Mains · 2016 · Mains Paper III

Q1(h). HPLC and GLC

Question

State the principles of HPLC and gas–liquid chromatography.

Answer in brief

Both separate components through different distributions between mobile and stationary phases.

Key points

  • HPLC pumps a liquid mobile phase through a finely divided stationary phase at high pressure.
  • GLC uses an inert carrier gas and a nonvolatile liquid stationary film. Solutes repeatedly vaporise and dissolve in that film.
  • GLC retention depends on volatility and liquid-film affinity; HPLC can handle many nonvolatile or thermally sensitive solutes.

The full model answer

As written for the answer booklet: the diagram carries the working, the lines stay short. Read here only; it is not offered as a download.

Model answer to Q1(h), 2016 Mains Paper III: solution pages 3 and 4
Solution pages 3 and 4 of 22
Read the whole 2016 solution2016 question paper

CoversHPLCGLCChromatography

All parts of Question 1