Gasometric method :-
- There are number of gas but only few gas are used as inhalant.
- Inhalant are the drug or chemical which are in vapour form are inhaled in the body.
- Some gas are used as anaesthetic.
- Inhalation of gas cause change in physiological functions and bring pharmacological action. This action is depend on gas concentration.
- Therefore these gas used in therapeutic need to be checked for their purity and hence we need performing assay produced as per official pharmacopoeia.
- For assay of these inhalant gases method ised is referred as gasometric method.
The apparatus consists of a nitrometer which is connected by rubber tubing to a balance arm.
The absorbing liquid specified in the monograph is filled in the gas burette by raising and lowering the balance arm of the burette.
The gas is then passed in the gas burette with the help of a gas pipette.
Here the gas get absorbed in the concern liquid and the remaining volume of gas i.e. unabsorbed volume of the gas is measured.
The standard given for this is the volume of the gas remaining unabsorbed should not exceed 1% V/V.
1. Official Gas :- oxygen
Absorbing liquid :- ammonium hydroxide + ammonium
2. Official Gas :- carbon dioxide
Absorbing liquid :- 50% w/v potassium hydroxide solution.
3. Official Gas :- Nitrous oxide
Absorbing liquid :- liquid oxygen
1. Which is official method for assay of Gas ?
B. Gasometric method
C. Karl-fischer titration
D. Diazotization Titration
2. Which sentence is false about Gasometric method ?
A. It is official standard method of gas assay.
B. The volume of the gas remaining unabsorbed should not exceed 1 % v/v
C. Nitrous oxide absorbing liquid is liquid oxygen.
D. Gas metrics method is unofficial method.
3. Which absorbing liquid is used in carbon dioxide assay ?
A. Liquid oxygen
B. Liquid Nitrogen
C.50% w/v potassium hydroxide solution
D. None of above.
4. How many percentage of the gas is unabsorbed in Gasometric method ?
5. Mixture of solutions of ammonium hydroxide and ammonium are absorbing liquid for which gas ?
6. Liquid oxygen is absorbing liquid for which gas ?
C. Carbon monoxide
D. Carbon dioxide