Impex Produkter 985012 NANOCOLOR COD 60000 Instruction Manual

Impex Produkter 985012 NANOCOLOR COD 60000

Overview

The test is suitable for the photometric determination of the chemical oxygen demand (COD). The test is equivalent to the methods EPA 410.4, APHA 5220D, DIN ISO 15705–H45 and DIN 38409–H41-1. This test is suitable for water, wastewater and sludge.

• Measuring range:
  • 5.0–60.0 g/L O2 (Methode 0121)
  • 5000–60000 g/L O2 (method 0122)
• Number of tests : 20
• Wavelength for photometric determination : 595 / 605 / 620 nm
• Shelf life : 12 months
• Storage temperature : 15–25 °C
• Storage conditions : protected from sunlight, upright.

Method

The organic compounds of a sample are oxidized by heating the sample in a mixture of sulphuric acid and potassium dichromate. The chemical oxygen demand (COD) of a water sample is the con-centration of oxygen that is equivalent to the amount of potassium dichromate consumed. The change in the potassium dichromate concentration is determined via the change in absorbance after digestion.

Interferences

The following contaminants do not interfere with the test up to the indicated concentrations. The cumulative effect of different interfe-ring ions has not been tested.

Data in mg/L: Cl-: 15000

Important: For samples in which the chloride content is high, shake the tube to suspend the precipitate prior to adding the sample. If the chloride content is greater than 15,000 mg/L, you must dilute the sample or use a chloride masking agent (REF 918911). Once it has reacted in the heating block, the solution must not be cloudy; turbidity can result in high COD values. This method is not suitable for analyzing seawater.

Reagents and accessories

Contents of reagents set:
20 test tubes R0

Required devices:

• MACHEREY-NAGEL photometer
• MACHEREY-NAGEL heating block
• Digital piston pipette 100–1000 µL (REF 91677) with pipette tips (REF 91667)
• Digital piston pipette 50–200 µL (REF 916914) with pipette tips (REF 916915)
• Safety bottle for shaking COD tubes (REF 91637\)

Standards
NANOCONTROL Multistandard Sewage inflow (REF 925012)

Sampling and preparation
See DIN EN ISO 5667-3-A 21.

Quality control
The measurement of a blank value and a standard is recommended before every measuring series as quality control measure.

Quality data

The following data were determined during production according to ISO 8466-1 and DIN 38402-A51:

• Number of LOTs : 20
• Standard deviation of the method : ± 0.6 g/L O2
• Coefficient of variation of the process : ± 1.66 %
• Confidence interval : ± 1.3 g/L O2

Specified data for procedure:

• Sensitivity (absorbance of 0.010 A corresponds to) : 0.3 g/L O2
• Accuracy of a measurement value : ± 1.2 g/L O2

LOT-specific certificates are available at www.mn-net.com.

Procedure

1. Put the sediment in the reaction cuvette into suspension by swirling
2. Open round cell and hold slightly tilted
3. Pipette 0.2 mL of sample into test tube
4. Seal test tube and shake vigorously (use safety bottle, cuvette will become hot!).
5. Heat for 2 h at 148°C
6. Take the tube from the heating block
7. Shake again after 10 min. while still warm
8. Cool to room temperature
9. Clean outside of test tube
10. Measure

Notes
Test a sample of COD-free water (REF 918993) to generate a blank value for the reagent. When using a standard, the measured value is constant over a period of min. 30 min. The mixture may heat up significantly. When using other photometers, make sure measurements are possible in test tubes (16 mm OD) and calibrate the method. Information regarding safety can be found on the box’ label and in the safety data sheet. You can download the SDS from www.mn- net.com/SDS. 03/2021 www.mn-net.com

MACHEREY-NAGEL GmbH & Co. KG Neumann-Neander-Str. 6-8 52355 Düren Germany

• Tel.: +49 24 21 969-0 [email protected]
• Tel.: +41 62 388 55 00 [email protected]
• Tel.: +33 388 68 22 68 [email protected]
• Tel.: +1 484 821 0984 [email protected]

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