A: According to our quality tests, most binding gels (except precipitated ferrihydrite gel) and diffusive gels (except bis-acrylamide cross-linked polyacrylamide gel known as BPA) can be stored at room temperature for more than one year in a well-sealed container with 0.01-0.03 M NaNO3 or NaCl solution.

For loaded DGT devices packed in a plastic bag, evaporative leakage could induce dehydration of diffusive gels and affect DGT performance.  To eliminate this impact, we normally add 0.4 mL of NaNO3 or NaCl solution to each plastic bag for long term storage. There was no significant influence on measurements using DGT devices stored in these bags at room temperature for one month and at 4oC for six months. The small amount of solution remaining in the plastic bag should not present  a problem. The DGT devices can be deployed directly on removal from the bag.