Pharmaceutical analysis- Non- aqueous titration

-

Non-aqueous titration

Introduction-; 

Most of the Titration are performed in the aqueous media means water is used as solvent.
There may be difficulty if reactant is insoluble in water, or reactant is reactive with water or the analyte is either too weak acid or base.

"Non - aqueous titration refers to a type of titration in which the analyte substance is dissolved in a solvent which does not contain water" .

Types of solvent-;

The solvent are classified into 4 groups—
1. Protogenic solvent
2. Protophillic solvent
3. Amphoteric solvent
4. Aprotic solvent

1. Protogenic solvent-;

• These are acidic solvent which readily do not proton and are used to enhance the basicity of weak base .

Example- Sulphuric acid, acetic acid, formic acid etc.

2.Protophillic solvent-;

• These solvent are basic in nature , possessing a high affinity for proton , these enhances the acidity of weak acids.

Example- Ammonia, pyridine etc .

3. Amphoteric solvent-;

• These solvent have properties which are protophillic as well as protogenic.

Example-; Acetic acid, alcohol,water etc

4. Aprotic solvent-;

• These solvent are neutral in change and are chemically inert.

Example-; Chloroform, Benzene etc

Types of non- aqueous titration-;

• it is two types;
a. Acidimetry titration
b. Alkalimetry titration

a. Acidimetry titration-;

• It involves the quantitative estimation of weak bases by non- aqueous titration.
• Titrant used in acidimetry titration is acidic in nature that way this titration is known as acidimetry titration.

Example- perchloric acid .

• In this type of titration aprotic or protogenic solvent are used.

Example-;  Benzene, Chloroform, glacial acetic acid, formic acid etc. 

Sample which can be determined by acidimetry—
Example-; ephedrine, morphine, acyclover , Adrenaline , caffeine.

• Indicator used in acidimetry titration are —

        • crystal violet ( 0.5% w/v in glacial acetic acid)
       • Thymol blue ( 0.2%w/v in methanol).
• After titration colour change from violet to green.

Estimation of Ephedrine hydrochloride-;

       Accurately weigh about 0.5gm ephedrine hydrochloride.
                                     ⬇️
     dissolve in 25ml of glacial acetic acid
                                     ⬇️
     Add 10 ml mercuric acetate & few drops of crystal violet indicator.
                                     ⬇️
       Titrate the solution with 0.1 M perchloric acid until colour change from blue/ violet to greenish blue 
                                     ⬇️
           Note the quantity of titrant us

 Each ml of 0.1M perchloric acid solution=0.02017gm of Ephedrine hydrochloride.

Estimation of sodium benzoate-;

Accurately weigh 0.6 gm sodium benzoate and tranfers into 250ml of breaker.
                                 ⬇️
         Add 100 ml glacial acetic acid
                                 ⬇️
      Stirling until the sample is completely dissolved
                                  ⬇️
           Add crystal violet indicator
                                  ⬇️ 
Titrate with 0.1 N perchloric acid solution.
                                  ⬇️
Calculate the consumed volume of titrant.

Each ml of 0.1 N perchloric acid= 0.01441gm of sodium benzoate.

b. Alkalimetry-;

• This titration is used for the quantitative estimation of acidic drugs.
• Titrant used in alkalimetry titration is basic/ alkaline in nature.
Example-; sodium methoxide.
• In this Titration protophillic nature of solvent are used.
Example-; Ammonia, pyridine, DMF.
• Sample which can be determined be alkalimetry titration are.

1. Acetazolamide

2. Allopurinol

• Indicator used in alkalimetry titration are—
      
      • 0.5% w/v Thymol blue in methanol (pink - blue)
      • 0.2 % w/v azo violet in benzene.



                                 Thankyou





Comments

Post a Comment

Popular posts from this blog

Pharmaceutical engineering || Manometer

-
Image
        ★ Manometer★ • It is a device of instrument which is Used to measure pressure difference. Types of manometer- 1. Simple manometer a. U tube manometer b. Piezometer c. Single column manometer 2. Differential manometer a. U tube differential manometer b. Inverted U-tube differential manometer Simple manometer-; Simple manometer are made up glass tubes one end of those remain open to the atmosphere and the other hand are collected to the point were pressure to be measure. Principle-; • It were one of the principle of hydrostatic equilibrium and is used for measuring pressure ( static pressure). • Exceded by a stil liquid or gas hydrostatic equilibrium state that the pressure at any point in a fluid at rest is equal and it's value is just the weight of the over living Fluids. • The manometer is the simplest instrument for gauge pressure low range pressure instrument alaning the pressure against the weight of a coloum In liquid. • The action of are manometer depen...
Read more

B.pharma 1st semester Notes pharmaceutical analysis unit - 4th- Redox Titrations

-
Image
          //  Redox Titrations \\ • A Redox titration is a type of titration in which titrant and titrand react through and oxidation reduction reaction. • The end point of a Redox titration is detected by using indicators. Principles of Redox titration; Reduction—  • The subtances  can undergo reduction by followin. • The addition of hydrogen. •The removal of oxygen. • The acceptance of electrons. Example- fe³+→fe ²+  Oxidation— • Addition of oxygen. • Removal of hydrogen. • Loss/ donation of electrons. Example- fe²+ → fe³+ Oxidising agents;  •An oxidising agent is a chemical species that causes that other reactant in a redox reaction to be oxidized, and it is always reduced in the process. Example- Ag + , O², O³
Read more

Diabetes mellitus short notes -

-
               ;Diabetes mellitus; • Carbohydrate body turns it into a sugar called glucose and sends that to your bloodstream. • pancreas release insuline  Type 1 diabetes; • It's an autoimmune disease. • 10 % of people who have diabetes have type 1. • It was once better known as" Juvenile" diabetes • It is also called insulin dependent diabetes. Type 2 diabetes; • 95% of people have type 2 diabetes.   Symptoms of diabetes; • Increase thirst  • Weak, tired feeling. • Blurred vision . • Number or tingling in the hand or feet. • slow - healing sores or cuts. • unplanned weight loss. • Frequent urination. • Frequent unexplained infection. • Dry mouth  Treatment; • Diuretic • Drugs that ↑ insulin production. • Drugs that ↑ sugar absorption. • Nutritional & meal time. • Exercise, reduced stress. • Quit smoke& alcohol.
Read more