“…58 The appearance of its aromatic proton peaks observed at 7 to 8 ppm even after the AORFB test is clear evidence that this is chemically stable. 59,60 Besides that, the chemical degradation of NQ-OH was generally observed when its concentration was high. However, the concentrations of NQ-OH used for this study were low enough, so the possibility of occurrence of its chemical degradation is low.…”