DensityRefractiveIndexQualityChecker

Density & Refractive Index Quality Checker — Control of Density and Refractive Index

ℹ️  Utility checks critical physical parameters of liquid substances:
   • Density: within ±0.002 g/cm³ of reference
   • Refractive Index (nD): within ±0.001 of reference
   • Measurement Temperature: 20.0 ± 0.5 °C

⚠️  CRITICAL: Deviation in density or nD indicates impurities or incorrect identity!
   These methods are primary for rapid identification of pure solvents and liquid APIs.

Usage:
 DensityRefractiveIndexQualityChecker.exe                            → demo mode (console output)
 DensityRefractiveIndexQualityChecker.exe input.csv output.json      → evaluate your data

Input format:
BatchNumber,DensityGcm3,RefractiveIndex,TemperatureC

Example:
 LIQ-SOLV-2026-001,0.785,1.377,20.0

— WHY IS THIS NEEDED?
Density and refractive index are fundamental physical constants strictly regulated by pharmacopoeias.
• Ph. Eur. 2.2.5 and USP <841> describe density determination methods (often using oscillating U-tubes).
• Ph. Eur. 2.2.6 and USP <831> describe refractometry methods.
• These parameters are sensitive to substance purity. Even small amounts of impurities (water, other alcohols) significantly change readings.
• Used for incoming control of solvents, oils, liquid excipients (e.g., glycerin, propylene glycol).

⚠️  CRITICAL:
• Temperature must be strictly controlled (usually 20°C) as density and nD are highly temperature-dependent.
• Modern digital densimeters and refractometers (Anton Paar, Mettler Toledo) automatically compensate for temperature, but validation requires verification.
• Air bubbles in the densimeter cell lead to gross errors.
• Refractometry requires a clean prism and proper sample application.

Key features:
• Dual identity control (Density + RI).
• Measurement temperature regime check.
• Compliance with Ph. Eur. and USP requirements.

Critical parameters:
• Density: Target ± Tolerance
• Refractive Index: Target ± Tolerance
• Temperature: 20.0 ± 0.5 °C

💡 Usage tips:
1. Calibrate instruments daily using air and water (or standard samples).
2. Remove air bubbles before density measurement.
3. For viscous liquids, ensure the cell is completely filled and thermostated for sufficient time.
4. Compare results with the supplier's Certificate of Analysis (CoA).
5. Use these data as a rapid screening tool before more complex chromatographic analysis.

⚠️ Note: Density and refractive index often correlate. Their combined use increases identification reliability compared to using only one parameter.