|Range||Method||Kit Catalog No.||No. of Vials|
|0-150 ppm (LR) USEPA-accepted*||Dichromate Reactor Digestion||K-7350S *||25|
|0-150 ppm (LR) USEPA-accepted*||Dichromate Reactor Digestion||K-7355 *||150|
|0-150 ppm (LR) Mercury-free||Dichromate Reactor Digestion||K-7351S||25|
|0-150 ppm (LR) Mercury-free||Dichromate Reactor Digestion||K-7356||150|
|0-1500 ppm (HR) USEPA-accepted*||Dichromate Reactor Digestion||K-7360S *||25|
|0-1500 ppm (HR) USEPA-accepted*||Dichromate Reactor Digestion||K-7365 *||150|
|0-1500 ppm (HR) Mercury-free||Dichromate Reactor Digestion||K-7361S||25|
|0-1500 ppm (HR) Mercury-free||Dichromate Reactor Digestion||K-7366||150|
|0-15,000 ppm (HR+) Not USEPA Approved*||Dichromate Reactor Digestion||K-7370S *||25|
|0-15,000 ppm (HR+) Not USEPA Approved*||Dichromate Reactor Digestion||K-7375 *||98|
|0-15,000 ppm (HR+) Mercury-free||Dichromate Reactor Digestion||K-7371S||25|
|0-15,000 ppm (HR+) Mercury-free||Dichromate Reactor Digestion||K-7376||98|
|Product||Kit Catalog No.|
|COD Calibration Standard, 1000 ppm||A-7301|
|COD Calibration Standard, 10,000 ppm||A-7310|
The determination of Chemical Oxygen Demand (COD) is widely used in municipal and industrial laboratories to measure the overall level of organic contamination in wastewater. The contamination level is determined by measuring the equivalent amount of oxygen required to oxidize organic matter in the sample.
The Dichromate Reactor Digestion Method
References: USEPA Methods for Analysis of Water and Wastes, Method 410.4 (1983). APHA Standard Methods, 22nd ed., Method 5220 D-1997. A. M. Jirka and M. J. Carter, "Micro Semi-Automated Analysis of Surface and Wastewaters for Chemical Oxygen Demand," Analytical Chemistry, Vol. 47, p.1397 (1975). J. A. Winter, "Method Research Study 3, Demand Analysis, An Evaluation of Analytical Methods for Water and Wastewater," USEPA, 1971. ASTM D 1252-00, Chemical Oxygen Demand (Dichromate Oxygen Demand) of Water, Test Method B.
CHEMetrics offers two dichromate reactor digestion methods for fast, easy, safe determinations of low-, mid-, and high-range COD levels in wastewater: the USEPA-accepted Method*, and a mercury-free method. The products using the USEPA-accepted method contain mercuric sulfate in the reagent to eliminate chloride interferences. The mercury-free product line is applicable when chloride interference is not a concern and USEPA reporting is not required.
CHEMetrics' leakproof reagent vials contain premeasured solutions of sulfuric acid and potassium dichromate. To perform the COD determination, the analyst simply removes the Teflon-lined screw cap from the vial, adds sample to the vial, and replaces the cap. The vial is then heated for two hours at 150°C in a standard digestor block. Once digestion is completed, results are obtained using any photometer that accepts 16-mm diameter cells. CHEMetrics COD vials can be directly used in our V-2000 multi-analyte photometer, CHEMetrics' single analyte COD photometers, as well as in many Hach1 spectrophotometers. Built-in Hach COD methods and calibrations can be used without the need for a new calibration. A generic calibration equation is included within the CHEMetrics™ kit for use with other spectrophotometers.
*Contains mercury. Dispose according to local, state or federal laws.
COD Procedure - For use when comparing COD Vials to alternative suppliers
1 NOTE: No endorsement by Hach Company is implied or intended.