Each lot of vials is checked against a standard solution and against a competitor’s vials to ensure that they give the proper response after digestion.
The vials contain enough mercuric sulfate to compensate for up to 2,000 mg/L chloride.
Each of these vials contain 0.07425 g Hg.
COD vials contain several hazardous reagents. Mercuric sulfate is required by regulating authorities to compensate for chloride interference. Potassium dichromate is the active color changing species in the reaction. Sulfuric acid gets the solution into an acceptable pH range for the reaction to occur. Silver sulfate serves as a catalyst for the oxidation of some of the more complex organic compounds. All four of these reagents qualify the mixture for the hazardous list. Please email me at firstname.lastname@example.org if you would like a MSDS sheet for complete documentation.
For the 0-150 mg/L COD vials that contain Hg there is 0.07425g of Hg / vial.
5 years from the date of manufacture.
We are using a competitive brand of COD vials w/Hg and still having a positive Cl interference down to a 250 ug Cl level. Do you have experimental data to show your vials eliminate Cl interference?
Our COD vials contain 40mg of mercuric sulfate in each vial. Mercuric sulfate is most effective with the ratio of mercuric sulfate to chloride is 10:1. Our vials will effectively treat chloride interferences in a sample containing up to 2000 ppm of chloride (4 mg). For samples exceeding 2000ppm of chloride we recommend diluting the sample prior to digestion.