Chemical and Biological Stability of Indole-3-Butyric Acid (IBA) After Long-term Storage at Selected Temperatures and Light Regimes

Concentrated [4.9 mM (1,000 ppm) and 24.6 mM (5,000 ppm)] IBA solutions in 50% isopropyl alcohol were stored in amber and clear glass bottles at 3 temperatures [22–25°, 6°, O°C (72–77°, 43°, 32°F)]. No significant change in biological activity of the solutions or breakdown of IBA was observed for solutions stored for 4 and 6 months. Solution color changed during storage. Color development was dependant on storage temperature, but not on exposure to light. Chemical names used: IAA = indole-3-acetic acid; IBA = indole-3-butyric acid; NAA = 1-naphthaleneacetic acid