The K-7356 COD Vials Kit was designed to accurately measure COD in water from 0-150 ppm. 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.
Dichromate Reactor Digestion Method:
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.
How to use:
- Homogenize 500 mL of sample for 2 minutes in a blender.
- Preheat the digester block to 150 degrees Celsius
- Pipet 2 mL of the sample into the COD vial.
- Cap the vial and invert 10 times to mix well.
- Wipe vial with damp towel and place in preheated digester block.
- Prepare reagent blank by repeating steps 3-5 with dionized water.
- Allow vials to heat in digester block at 150 degrees Celsius for 2 hours.
- Turn digester block off and allow vials to remain in unit to cool for 15-20 minutes.
- Remove vial, invert several times, and place on rack to cool for at least 30 minutes.
- Use instrument to obtain results
WARNING! This product can expose you to chemicals including chromium, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.