Quiz 1

......................... is the most used supercritical fluid

• Water

• Methane

• Carbon dioxide (CO2)

• Ethanol

........................... separates an analyte through partitioning between two immiscible solvents

• SE

• Liquid-liquid extraction (LLE)

• SFE

• SPE

In liquid-liquid extraction, if the selectivity is unity, then

• (a) separation of the constituents is most effective

• (b) no separation is possible

• (c) amount of solvent requirement is minimum

• (d) solvent flow rate should be very high

Which of the following operations is more economical for concentration of acetic acid from very dilute aqueous solution?

• (a) evaporation

• (b) solvent extraction

• (c) atmospheric distillation

• (d) drying

The temperature of a supercritical fluid should be above its

• (a) freezing point

• (b) boiling point

• (c) critical point

• (d) none of these

Heat sensitive material with very high latent heat of vaporisation may be economically separated by

• (a) distillation

• (b) evaporation

• (c) liquid extraction

• (d) absorption

.......is a technique performed to extract solid or semi-solid samples using organic solvents.

• Supercritical Fluids Extraction

• Pressurized Fluids Extraction

• Soxhlet Extraction

• Enzymatic Assisted Extarction

Methanol is added to the liquid CO2 during supercritical fluids extraction to

• changes its polarity

• increases the solubility of samples

• increase the extraction efficiency

• change the density

In accelerated solvent extraction (ASE), polar solvent is preferred compare to non-polar solvent. Please explain

The operating parameters that need to be optimized in ASE are:

• Time

• Pressure

• pH

• flow rate