1-Aminohydantoin hydrochloride is a major metabolite of nitrofurantoin in animal tissues and can be used as a standard for the determination of residues of veterinary agents in meat, milk et.al. 1-Aminohydantoin hydrochloride covalently binds to tissue proteins and is released from the tissues under slightly acidic conditions and derivatized with 2-nitrobenzaldehyde to form nitrophenyl derivatives of AHD before detection.

Providing storage is as stated on the product vial and the vial is kept tightly sealed, the product can be stored for up to 24 months.
Wherever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20°C. Generally, these will be useable for up to one month. Before use, and prior to opening the vial we recommend that you allow your product to equilibrate to room temperature for at least 1 hour.