StannousChlorideSolutionStabilityChecker

Utility description: Stannous Chloride Solution Stability Checker

Stannous Chloride Solution Stability Checker — Quality control of Stannous Chloride solution

ℹ️  Utility checks the quality of Stannous Chloride (SnCl2) solution:
    • Sn(II) concentration (degradation ≤10%)
    • pH of the medium (hydrolysis prevention)
    • Visual inspection (no precipitate)
    • Shelf life depending on storage conditions

⚠️  CRITICAL: Oxidized Sn(II) does not reduce Tc-99m!
    Using unstable solution will lead to rejection of all radiopharmaceuticals.
    Store only under inert gas (N2/Ar) at low pH.

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

Input format:
SolutionBatchID,PreparationDate,InitialConcentrationMgPerML,MeasuredConcentrationMgPerML,PHValue,HasPrecipitate,StorageCondition,DaysSincePreparation,TemperatureC

Example (HasPrecipitate: true/false):
  SN-CL2-2026-A01,2026-07-01,10.0,9.8,1.2,false,N2_Ar,20,4.0

— WHY IS THIS NEEDED?
Stannous Chloride (SnCl2) is a key reducing agent in nuclear medicine.
• Sn(II) is easily oxidized by air oxygen to Sn(IV), which has no reducing properties.
• In neutral or slightly alkaline media, Sn(II) undergoes hydrolysis forming insoluble Sn(OH)Cl precipitate.
• Solution quality directly determines Tc-99m labeling efficiency.
• Regular monitoring helps avoid mass rejection of expensive isotope preparations.

⚠️  CRITICAL:
• Sn(II) degradation >10% — solution is considered unfit for precision labeling.
• Appearance of precipitate — irreversible sign of hydrolysis. Solution must be discarded.
• pH must be maintained at 0.5–2.0 (usually by adding HCl). pH increase leads to rapid precipitation.
• Shelf life is drastically reduced upon contact with air: from 30 days (under nitrogen) to 1 day (in air).

Key features:
• Calculation of Sn(II) oxidation percentage based on titrimetric data.
• Hydrolysis risk assessment by pH value.
• Dynamic shelf life calculation depending on declared storage conditions (N2, Sealed, Air).
• Visual control as a critical quality parameter.
• Compliance with internal GMP standards for radiochemical laboratories.

Critical parameters:
• Sn(II) concentration: ≥90% of initial
• Degradation: ≤10%
• pH: 0.5–2.0
• Precipitate: Absent
• Shelf life (N2): ≤30 days
• Shelf life (Air): ≤1 day

💡 Usage tips:
1. Sn(II) concentration is determined by iodometric titration in an inert atmosphere.
2. Solution should be prepared immediately before use or stored under a layer of mineral oil/inert gas.
3. Use only freshly prepared HCl solutions for dilution, as water contains dissolved oxygen.
4. If even slight cloudiness is detected, the solution is rejected without additional tests.
5. Keep a strict log of SnCl2 vial openings.

⚠️ Note: SnCl2 stability is the "Achilles' heel" of the entire Tc-99m technology. Even if the isotope is ideal and the kit is high-quality, a poor reductant will negate all efforts. This utility serves as the first line of defense against radiopharmaceutical rejection.