BP110P PHARMACEUTICAL INORGANIC CHEMISTRY (Practical)

Limit test for Arsenic Principle: Limit test of Arsenic is based on the reaction of arsenic gas with hydrogen ion to form yellow stain on mercuric chloride paper in presence of reducing agents like potassium iodide. It is also called as Gutzeit test and requires special apparatus. Arsenic, present as arsenic acid in the sample is reduced to arsenious acid by reducing agents like potassium iodide, stannous acid, zinc, hydrochloric acid, etc. Arsenious acid is further reduced to arsine (gas) by hydrogen and reacts with mercuric chloride paper to give a yellow stain.   H 3 AsO 4  + H 2 SnO 2  → H 3 AsO 3  + H 2 SnO 3   Arsenic acid            Arsenious acid   H 3 AsO 3  + 3H 2  → AsH 3  + 3H 2 O    Arsenious acid    Arsine The depth of yellow stain on mercuric chloride paper will depend upon the quality of arsenic present in the sample. Procedure: Test solution: The test solution is prepared by dissolving specific amount in water and stannated HCl (arsenic free) and kept in a wide mouthed

 Limit test for Heavy metals Limit test for Lead Lead is a most undesirable impurity in medical compounds and comes through use of sulphuric acid, lead lined apparatus and glass bottles use for storage of chemicals. Principle: Limit test of lead is based on the reaction of lead and diphenyl thiocabazone (dithizone) in alkaline solution to form lead dithizone complex which is read in color. Dithizone is green in color in chloroform and lead-dithizone complex is violet in color, so the resulting color at the end of process is red. Procedure: Test sample Standard compound A known quantity of sample solution is transferred in a separating funnel A standard lead solution is prepared equivalent to the amount of lead permitted in the sample under examination Add 6ml of ammonium citrate Add 6ml of ammonium citrate Add 2 ml of potassium cyanide and 2 ml of hydroxylamine hydrochloride Add 2 ml of potassium cyanide and 2 ml of hydroxylamine hydrochloride  Add 2 drops of phenol red Add 2 drops of

Modified limit test for Chlorides and Sulphates Limit test for Iron Experiment No. 3a Aim: To carry out the Modified Chloride limit test of the given test substance.  Requirements: (a) Glasswares: Nesslers’ cylinder, measuring cylinder and glass rod.   (b) Chemicals: Dil. Nitric acid, 0.1 M silver chloride, conc. HCl, distilled water.  Principle: Limit test of chloride is based on the precipitation reaction. The precipitates of chlorides develop on reaction of soluble chloride with silver nitrate in the presence of dilute nitric acid to form silver chloride, which appears as solid particles (opalescence) in the solution. The intensity of turbidity depends on the amount of chlorides present in the test substance.  Procedure: With reference to International Pharmacopoeia 6th Edition 2016, the limit test of chloride has been modified in the context of standard solution preparation. Earlier the standard solution of chloride was prepared by dissolving sodium chloride (NaCl, known Cl− impur

 Limit test for Sulphates  Principle: Limit test of sulphate is based on the reaction of soluble sulphate with barium chloride in presence of dilute hydrochloric acid to form barium sulphate which appears as solid particles (turbidity) in the solution. Procedure: Test sample Standard compound Specific weight of compound is dissolved in water or solution is prepared as directed in the pharmacopoeia and transferred in Nessler cylinder Take 1ml of 0.1089 % W/V solution of potassium sulphate in Nessler cylinder Add 2ml of dilute hydrochloric acid Add 2ml of dilute hydrochloric acid Dilute to 45 ml in Nessler cylinder Dilute to 45 ml in Nessler cylinder Add 5ml of barium sulphate reagent Add 5ml of barium sulphate reagent Keep aside for 5 min Keep aside for 5 min Observe the Turbidity Observe the Turbidity Barium sulphate reagent contains barium chloride, sulphate free alcohol and small amount of potassium sulphate. Observation: The turbidity produce in sample solution should not be greater

 Experiment No. 1 Limit test for Chlorides  Principle: Limit test of chloride is based on the reaction of soluble chloride with silver nitrate in presence of dilute nitric acid to form silver chloride, which appears as solid particles (Opalescence) in the solution. Procedure: Test sample Standard compound Specific weight of compound is dissolved in water or solution is prepared as directed in the pharmacopoeia and transferred in Nessler cylinder Take 1ml of 0.05845 % W/V solution of sodium chloride in Nessler cylinder Add 1ml of nitric acid Add 1ml of nitric acid Dilute to 50ml in Nessler cylinder Dilute to 50ml in Nessler cylinder Add 1ml of AgNO 3  solution Add 1ml of AgNO 3  solution Keep aside for 5 min Keep aside for 5 min Observe the Opalescence/Turbidity Observe the Opalescence/Turbidity Observation: The opalescence produce in sample solution should not be greater than standard solution. If opalescence produces in sample solution is less than the standard solution, the sample wi

  BP110P           PHARMACEUTICAL INORGANIC CHEMISTRY (Practical)  4 Hours / Week          I                 Limit tests for following ions a)       Limit test for Chlorides and Sulphates b)       Modified limit test for Chlorides and Sulphates Limit test for Iron c)       Limit test for Heavy metals Limit test for Lead d)      Limit test for Arsenic II               Identification test a)       Magnesium hydroxide Ferrous sulphate Sodium   Bicarbonate Calcium gluconate Copper sulphate III             Test for purity a)       Swelling power of Bentonite b)       Neutralizing capacity of aluminum hydroxide gel c)       Determination of potassium iodate and iodine in potassium Iodide IV       Preparation of inorganic pharmaceuticals a)       Boric acid b)       Potash alum c)       Ferrous sulphate Recommended Books (Latest Editions) 1.       A.H. Beckett & J.B. Stenlake's, Practical Pharmaceutical Chemistry Vol I & II, Stahlone Press of Un