Figure 3
From: Crystal structure and characterization of pyrroloquinoline quinone disodium trihydrate
Samples with different water content prepared by drying PQQ disodium trihydrate. Images of the samples with different water content. Near-infrared (NIR) spectra of dried samples. All the samples with different water content show a water content of around 12% after being subjected to a relative humidity (RH) of 75% at 40°C for 1 day.