JNTU B.Pharmacy I Year PHARMACEUTICAL ANALYSIS-I Previous Question Paper (July/August-2021 - R17)

Analytical techniques are broadly classified based on the nature of the measurement or the property being analyzed:

1. Classical Methods (Chemical Methods): These rely on chemical reactions and stoichiometry. They include Volumetric Analysis (titrimetry based on volume measurement) and Gravimetric Analysis (based on the measurement of mass of a pure substance).
2. Instrumental Methods (Physicochemical Methods): These rely on the measurement of physical properties related to the concentration of the analyte. They are categorized into:
   • Spectroscopic Methods: Measurement of interaction between matter and electromagnetic radiation (e.g., UV-Visible, IR, NMR, Atomic Absorption Spectroscopy).
   • Electroanalytical Methods: Measurement of electrical properties such as potential, current, or resistance (e.g., Potentiometry, Conductometry, Polarography).
   • Chromatographic Methods: Separation techniques based on differential distribution between stationary and mobile phases (e.g., HPLC, GC, TLC, Paper Chromatography).
   • Thermal Methods: Measurement of physical properties as a function of temperature (e.g., TGA, DTA, DSC).

Concentration expresses the amount of solute present in a given quantity of solvent or solution. The primary methods include:

• Molarity (M): Number of moles of solute per liter of solution.
• Molality (m): Number of moles of solute per kilogram of solvent.
• Normality (N): Number of gram equivalents of solute per liter of solution.
• Formality (F): Number of formula weights of solute per liter of solution, often used for ionic salts.
• Mole Fraction (X): The ratio of the number of moles of one component to the total number of moles of all components in the mixture.
• Percentage Concentration: Expressed as weight/weight (w/w), weight/volume (w/v), or volume/volume (v/v) based on 100 parts of the total.
• Parts Per Million (ppm) and Parts Per Billion (ppb): Used for trace analysis, representing the number of parts of solute per million or billion parts of solution.