Aldehydes, AdBlue

OELCHECK test instrument: PerkinElmer Lambda 365+ UV-VIS Spectrophotometer
Sample volume: 20 ml
Unit: mg/kg
Test result: Determination of the content of free and bound aldehyde in AdBlue, calculated as formaldehyde.
Result range: 0,5 mg/kg – 10 mg/kg
Analysis for: AdBlue
Brief description: Formaldehyde forms a violet color complex with chromotropic acid in a strongly sulfuric acid solution with an absorption maximum at 565 nm. 
With a UV/VIS spectrophotometer, the formaldehyde content can be determined using a calibration curve prepared from formaldehyde standard solutions.
Statement: The determination of the aldehyde content is an essential quality criterion for the release of AdBlue according to ISO 22241-1.
Underlying test standard: ISO 22241-2 Anhang F