What is the shelf life for Lachat reagents/standards?
Lachat reagent and standard shelf life
Many Lachat methods will specify this within the preparation instructions. When they are not specified, one can consider the following general guidelines:
- Organic chemical dissolved in water: 1 day
- Inorganic salt in water (KCl, NaOH, CuSO4): 1 month
- Inorganic salts containing nutrients (KNO3, (NH4)2SO4): 2 days
- Stock Standards (>1 ppm): 1 week
- Working Standards (<1 ppm): 1 day