Cobalt and cobalt compounds can occur in the wastewater during the production of “aqueous dispersion paints, resin-bound plasters, and water-dilutable coatings, paint resins, and solvent-based coating materials”1.
Figure 1. Photometric determination with Nitroso-R-Salt
Cobalt salts have a carcinogenic effect when absorbed by inhalation, and in the event of oral uptake have a health-hazardous effect after repeated exposure2.
As a measure to prevent any impact on the environment and humans, the limit for the discharge of wastewater into water bodies imposed by Annex 9 of the German wastewater directive is set at 1 mg/l Co1.
The concentration of cobalt in water bodies and wastewater can be measured using the Spectroquant® Cobalt Cell Test Cat. No. 117244. This test offers a swift and precise alternative to conventional spectrometric methods such as ICP-OES (ISO 11885:2009, DIN 38406-24:1993-03, US EPA 200.7) and ICP-MS (US EPA 200.8). 3-6
This Application Note describes the determination of cobalt in wastewater from coating resins and coating materials using the Spectroquant® Cobalt Cell Test (Cat. No. 117244).
With the Spectroquant® Cobalt Cell Test the cobalt concentration in wastewater can be determined quickly and easily.
The methods are preprogrammed on the corresponding Spectroquant® photometers. Calibration is not necessary. All reagents required for the measurement are included in the test kit.
25 determinations can be carried out per package.
Cobalt(II) ions react with Nitroso-R salt to form an orange-red complex that is determined photometrically.
0.05 – 2.00 mg/l Co
Aqueous dispersion paints, resin-bound plasters, and water-dilutable coatings, paint resins, and solvent-based coating materials
Only necessary, if:
Sample needs to be preserved:
pH adjustment is needed:
Sample blank is needed:
Total cobalt should be determined:
For analytical quality assurance:
For the cobalt measurement one of the following Spectroquant® photometers is necessary:
If total cobalt should be determined, one of the following thermoreactors is necessary:
The Spectroquant® Prove Connect to LIMS software package provides an easy way to transfer your data into a preexisting LIMS system. This software can be purchased under:
The MQuant® StripScan App is an analytical detection system for the readout of test strips. The app can be downloaded via the IOS app store (the app is currently available for iPhones only). In addition to the app a reference card is necessary which can be purchased under the above-mentioned Cat. No..
Pipettes for pipetting volumes of 0.50 and 5.0 ml Only necessary for turbid solutions: Filter, e.g. Syringe filter Millex-LCR Filter 0.45 µm, hydrophiles PTFE, Cat. No. SLCR025NS
Sample blank (optional)
After measurement transfer the values measured on the Prove spectrophotometer using Prove Connect to LIMS.
1) Due to the instrument design of the Move 100 there may be differences in preparing the reagents as well as performing the measurement. Please see the Move 100 Manual for details.
2) For Details on how to perform the measurement step by step, see the instrument-specific manual
The cobalt determination is interfered with by the presence of certain substances. For details see the packaging insert of the test kit.
The objective of analytical quality assurance (AQA) is to secure correct and precise measurement results.
AQA is recommended before each measurement series. To check the measurement system (test reagents, measurement device, and handling) the ready-to-use cobalt standard solution Certipur®, concentration 1000 mg/l Co (Cat. No. 119785), can be used after diluting accordingly. Sample-dependent interferences (matrix effects) can be determined by means of standard addition.
For details on how to perform the AQA check see the instrument-specific manuals.
A certificate of analysis is provided for each batch and can be downloaded online on the product page of the test as well as a certificate of quality, where all batches are taken into account. In the certificates the performance characteristics determined in accordance with ISO 8466-2 and DIN 38402 A51 are given.
Nevertheless, it is recommended to determine the performance characteristic yourself so that all specific factors that may impact the performance (test reagents, measurement device, handling) are considered in the characteristic data.
The Spectroquant® Cobalt Cell Test is a fast and cost-effective alternative to spectrometric methods such as ICP-OES and ICP-MS for the determination of cobalt in wastewater.
The method is preprogrammed on the corresponding Spectroquant® photometers, so there is no need for a time-consuming calibration.
Stringent controls of the raw materials, effective in-process controls and documented final controls are a confirmation for the consistently high quality. Every product batch has an individual certificate, so there is no need to consider checking the quality of the test kit yourself. In addition, the quality certificates confirm consistent batch-to-batch quality.