Thermal Stability of the Guinea Green B Solution With Substrate and Its Application for the Detection of Cholinesterase Inhibitors

This study examines the thermal stability of a solution of Guinea Green B (GG) with substrate (butyrylthiocholine) as an indicator system for enzymatic detection of cholinesterase inhibitors. Such a solution may be used, for example, in detection tubes, field test kits, or laboratory analytical practice. The main parameter investigated was the resistance of the GG/substrate solution to prolonged thermal stress at 60 °C for 150 days. The aqueous solution, without additional stabilizing additives, retained practical functionality throughout the entire test period, whereas the corresponding phosphate‐buffered solution showed a pronounced loss of stability after short‐term thermal exposure. The functionality of the indicator solution was verified using neostigmine as well as nerve agents VX and A‐234. These results indicate that the GG/substrate solution is a promising thermally stable component for cholinesterase‐based detection systems.