Is there a procedure for regenerating the Lachat cadmium column?
Regeneration procedure for cadmium column
Hach has no official procedure for regenerating the Cadmium Column for Nitrate determination (Product # 50237A). The ISO procedure might be considered to regenerate cadmium (Cd) columns. Depending on the original quality of the cadmium column, this may nor mot be able to revive the column.
- Change the sample loop to 50 cm.
- Place all the manifold reagent lines in DI water.
- Place the Cd column in-line with the switching valve
- Run DI water through the Cd column.
- Set up a run of five injections of 0.1M HCl, followed by 3 injections of 2% CuSO4 . 5H2O (20g/L). The color of the cadmium should visibly change. If one end of the column is darker, the column can be switched around so the CuSO4 enters from the opposite end.
- Stop the pump.
- Place the buffer line in buffer solution
- Restart the pump.
- Run buffer through the Cd column for about 10 minutes.
- Install the nitrate manifold properly (using the proper sample loop), and do an efficiency test (NO2 and NO3 at level of the high standard) to verify the column is functioning properly.