COD Standard Solution, 300 mg/L, 200 mL. $29.16/EA. Sign in to Buy This item is not currently stocked. Allow 1-2 weeks. Please call us at 800-328-8378 if you’d like us to keep stock in the future. In Stock. Mercury Free COD Test Reagents. H28343-25. Ultra High Range (200 to 15000 mg/L), 25/pk.