HI-94754A-25 COD low range EPA approved Dichromate Method with Barcode

These high quality reagents are clearly marked with the lot number and expiry date on each box for traceability.

• Pre-dosed reagents for ease of use
• Prepared with high purity chemicals
• Marked with expiry date and lot number for traceability

The HI-94754A-25 COD kit contains 25 ready-to-use, barcoded vials containing pre-measured reagents. These high quality reagents follow the EPA approved method 410.4. In this method, a heated digestion under acidic conditions is required to allow the oxidisable organic compounds present in the sample to reduce hexavalent chromium to trivalent chromium, causing an orange tint in the sample. The intensity of colour is determined by a compatible photometer and the COD concentration is displayed in mg/L (ppm) O₂. These reagents are designed to be used with samples that have an expected range of 0 to 150 mg/L (ppm) O₂.

Automatic recognition of barcoded samples is an exciting feature when using the HI-94754A-25 reagent vials with a barcode compatible photometer. When inserted into the vial holder of the photometer, the sample method and range are automatically identified from the barcode. The barcode has four digits: the first two digits are for parameter identification and the second two digits are for reagent lot ID. Vials for different COD methods can be distinguished by a barcode printed on the vial - the barcodes for different methods are shown in the table below.

Comparison of Methods

EPA - The EPA approved method 410.4 for COD determination requires the use of mercuric sulphate (HgSO₄). Mercuric sulphate is present in the EPA reagent vials to mitigate the interference of chloride in the measurement sample. This is a common requirement for wastewater treatment plants and food manufacturing facilities which tend to have higher concentrations of chloride present in their effluent. When using reagents that follow the EPA method, it is important to treat used vials as hazardous waste, as mercury waste requires recycling.

Dichromate - The dichromate method is adapted from the standard EPA and ISO methods for determination of COD, which are approved to measure COD concentrations ranging up to 1500 mg/L O₂. The dichromate reagents can be used for accurate COD determination for samples with expected concentrations in the high range of 0 to 15000 mg/L O₂. It is important to treat used vials as hazardous waste, as mercury waste requires recycling.

Mercury-free - For those who do not wish to handle mercury reagents, our “green,” mercury-free reagents are available for COD determination. These reagents are more sensitive to chloride interferences, as mercuric sulphate is not present. While the mercury-free reagents are easier to dispose of, they may be unacceptable for reporting purposes.

ISO - The ISO approved method 15705 for COD determination also requires the use of mercuric sulphate (HgSO₄) to reduce the interference of chloride. Containing similar chemical reagents as the EPA method, it is important to treat used ISO vials as hazardous waste, as mercury waste requires recycling.

About the testing methods

• Dichromate EPA - Method with chromium-sulphuric acid is officially recognised by EPA for wastewater analysis.
• Dichromate mercury-free - This method is recommended for general purpose analysis with no chloride interference.
• Dichromate ISO - Method follows the official method ISO 15705. COD MR ISO method is 0 – 1000 mg/L. Meter can read higher.

Eight kits for all testing requirements

COD levels vary depending on the application and process measuring points. Hanna offers reagents to cover four separate ranges:

• Low range: 0 to 150 mg/L O₂
• Medium range: 0 to 1500 mg/L O₂
• High range: 0 to 15000 mg/L O₂
• Ultra High range: 0 to 60000 mg/L O₂

Pre-dosed vials

Each Hanna vial contains the exact amount of pre-dosed reagent needed for the analysis. The operator just needs to add a small quantity of the sample.

Safe reagents

Hanna COD reagents are safe for operators and the environment. Vials and caps have been designed to avoid accidental reagent spills. Due to the pre-dosed reagents, the amount of chemicals and handling time is minimised.

Quick and accurate measurements

With pre-dosed vials, test preparation time is dramatically reduced. There is no time-consuming reagent preparation procedure or glassware cleaning.

Compact packaging

Each set of COD Vials is stored in fully recyclable, sustainable, compact plastic packaging. The ergonomic box design reduces the volume of collateral waste and required storage space.

The procedure guide is printed on the inside of the box lid.

About Chemical Oxygen Demand (COD)

Chemical Oxygen Demand is a measure of biologically available and inert organic matter that is susceptible to oxidation by a strong oxidising agent.

The Hanna COD method is based on the well-established closed dichromate-reflux colorimetric method. The colorimetric measurement of COD is faster and easier to perform than the titrimetric analysis; additional regents are not required.

The sample is added to the reagent vial and digested under closed reflux conditions and allowed to cool before measurement is taken. Reference standards can be made using potassium hydrogen phthalate (KHP), 1mg of KHP is equal to 1.175 mg COD.

The advantage of using this method includes certifiable results as well as high accuracy.

About the application

COD is used as a measurement of pollutants. It is normally measured in both municipal and industrial wastewater treatment plants and gives an indication of the efficiency of the treatment process.

COD can be measured on both influent and effluent water. The efficiency of the treatment process is normally expressed as COD removal, measured as a percentage of the organic matter purified during the cycle.

COD also has applications in power plant operations, chemical manufacturing, commercial laundries, pulp and paper mills, agriculture and animal waste runoff, environmental studies and general education.

Hanna equipment can be used in the laboratory or for on-site testing. The measurement procedure has been designed for ease of use by personnel at any skill level.

Methods

Hanna’s COD reagents have been developed in accordance with Standard Methods 5220D, US EPA 410.4 and ISO 15705.

Why choose Hanna’s COD reagents

• All scales start from 0 ppm so with each kit, it is possible to cover even the low scale.
• All reagents include a certificate of analysis.
• High resistance to chlorides – up to 2000 ppm for low and medium range vials; up to 20000 ppm for high and Ultra high vials

Safety warnings

• Corrosive
• Serious Health Hazard
• Toxicity
• Hazardous to the Environment