Stress condition

Purity angle

Purity threshold

% Degradation

Acid degradation (0.1 N HCl/1 hr reflux)

0.080

0.694

3.79

Base degradation

(0.1 N NaOH/20 min reflux)

0.088

0.610

3.62

Peroxide degradation

(10% H₂O₂/20 min reflux)

0.109

0.663

0.79

Thermal (105˚C/72 hrs/solid)

0.090

0.684

0.56

Water

0.114

0.617

3.87

Sun light/UV light

0.102

0.626

0.73

Humidity

0.108

0.598

0.41