Limit Test of Nitrate – Principle, Procedure, Reaction, Observation Table & Viva Questions
📌 Introduction The Limit Test of Nitrate is performed to ensure that nitrate impurities present in inorganic substances are within acceptable limits. Excess nitrate is harmful and may alter chemical properties of drugs. This test is important in Pharmaceutical Inorganic Chemistry (B.Pharm – 1st Year) . 🎯 Purpose (Aim) To perform the Limit Test of Nitrate as per IP and compare the amount of nitrate impurity in the sample with the standard solution. 🧪 Principle Nitrate reacts with brucine (an alkaloid) in presence of sulphuric acid , producing a yellow to reddish brown color . If sample contains nitrate impurity → stronger color form If nitrate is within limit → sample color ≤ standard color 👉 Color comparison = Result of limit test 🧫 Reagents Required Reagent Purpose Brucine Solution Color development Concentrated Sulphuric Acid Reaction medium Sample Solution Test solution Standard Nitrate Solution Comparison Distilled Water Dilution 🧪 Apparatus Used Nessl...