Gas Chromatography

Question 1

For the separation of which of the following substances, Gas-solid chromatography is being used?
a) Thermally stable organic components
b) Volatile organic components
c) Thermally stable inorganic components
d) Low molecular weight gaseous species

Answer 1

d) Low molecular weight gaseous species

Question 2

Which of the following is not a feature of carrier gas used in gas chromatography?
a) It must be chemically inert
b) It should be suitable for the detector employed
c) It should not be completely pure
d) It should be cheap

Answer 2

c) It should not be completely pure

Question 3

Which of the following is the disadvantage of hydrogen, which can be used as carrier gas in gas chromatography?
a) Dangerous to use
b) Expensive
c) Reduced sensitivity
d) High density

Answer 3

a) Dangerous to use

Question 4

4. Which of the following is the disadvantage of helium, which can be used as carrier gas in gas chromatography?
   a) Dangerous to use
   b) Expensive
   c) Reduced sensitivity
   d) High density

Answer 4

b) Expensive

Question 5

Which of the following is the disadvantage of nitrogen, which can be used as carrier gas in gas chromatography?
a) Dangerous to use
b) Expensive
c) Reduced sensitivity
d) High density

Answer 5

c) Reduced sensitivity

Question 6

Slow injection of large samples leads to band broadening and loss of resolution.
a) True
b) False

Answer 6

a) True

Question 7

In which of the following methods are liquid samples injected into the column in gas chromatography?
a) Gas tight syringe
b) Micro-syringe
c) Rotary sample valve
d) Solid injection syringes

Answer 7

b) Micro-syringe

Question 8

What must be done to the solid samples for it to be introduced into the column without using solid injection syringes in gas chromatography?
a) Introduced in hot-zone of the column
b) Dissolved in volatile liquids
c) Introduced using rotary sample valve
d) Introduced using sampling loops

Answer 8

b) Dissolved in volatile liquids

Question 9

Which of the following is the commonly used support material for the packed column in gas chromatography?
a) Glass
b) Metal
c) Diatomaceous earth
d) Stainless steel

Answer 9

c) Diatomaceous earth

Question 10

Which of the following is the advantage of a straight packed column?
a) It can be packed uniformly
b) It can be repacked easily
c) It is compact
d) It is easier to heat it evenly

Answer 10

b) It can be repacked easily

Question 11

Which of the following is the disadvantage of coiled or helical shaped packed chromatographic column?
a) It cannot be packed uniformly
b) It cannot be repacked easily
c) It is not compact
d) It is not easy to heat it evenly

Answer 11

b) It cannot be repacked easily

Question 12

Capillary columns are open tubular columns constructed from which of the following materials?
a) Glass
b) Metal
c) Stainless steel
d) Fused silica

Answer 12

d) Fused silica

Question 13

Sample injection port must be maintained at a temperature at which rapid vaporization occurs but thermal degradation does not occur.
a) True
b) False

Answer 13

a) True

Question 14

Which of the following is not a desirable feature of the ovens used in gas chromatography?
a) It must have a fast rate of heating
b) Power consumption should be kept low
c) It must have maximum thermal gradients
d) It should have proper insulation

Answer 14

c) It must have maximum thermal gradients