Stability of ascorbic acid in human aqueous humor

Area of Science:

• Ophthalmology
• Biochemistry
• Analytical Chemistry

Background:

• Ascorbic acid (AA), also known as Vitamin C, is a crucial antioxidant found in high concentrations in human aqueous humor (AqH).
• Understanding the stability of AA in AqH is vital for accurate biochemical analysis and research related to ocular health.

Purpose of the Study:

• To investigate the stability of ascorbic acid in unacidified human aqueous humor under various storage temperatures.
• To determine the optimal storage conditions and timeframes for preserving AA integrity in AqH samples.

Main Methods:

• Human aqueous humor samples were stored at different temperatures: 27°C, 4°C, -20°C, and -80°C.
• Ascorbic acid degradation was monitored over time at each temperature condition without acidification.

Main Results:

• Significant AA degradation was observed at 27°C and 4°C within 24 hours.
• Storage at -20°C led to 37.5% degradation after 28 days.
• Storage at -80°C resulted in 10.7% degradation after 28 days, indicating better stability compared to -20°C.

Conclusions:

• Ascorbic acid in unacidified aqueous humor is unstable at room temperature and refrigeration.
• Long-term storage of AqH samples for AA analysis should be at -80°C.
• Measurements should ideally be conducted within 28 days for samples stored at -80°C to ensure reliable results.