Client context
AdBlue (AUS 32) is a solution of 32.5% urea in deionized water, used in SCR systems of Euro VI diesel engines to reduce nitrogen oxides. Urea concentration is a critical parameter: too low or too high reduces SCR efficiency and may create producer liability.
ISO 22241 requires verification of concentration, biuret, and absence of contaminants for each batch, and homogeneity in a tanker or IBC is critical in high-volume production.
Challenge.
- Urea concentration must fall within a narrow window of 32.5% ±0.7% (ISO 22241).
- Refractometry is fast but measures only dry matter and does not distinguish biuret.
- Full quality control awaits the laboratory, which slows down filling.
- Euro VI type approval (Reg. 2017/2400) makes AdBlue quality a formal requirement.
Solution
Spectrally™ X1 verifies urea concentration and solution homogeneity inline, directly at the filling point. It provides rapid qualitative and quantitative composition control without waiting for the laboratory.
We honestly note the method limitation: Raman confirms composition (urea, biuret) but does not replace trace metal determination (Fe, Ca, Na), which requires methods such as ICP or AAS. This is a complement to rapid control, not a substitute for full ISO 22241 certification.
Results
| Metric | Result |
|---|---|
| Parameter | Urea concentration and solution homogeneity, verification of the 32.5% ±0.7% window |
| Time | Verification at filling instead of waiting for the laboratory |
| Method limitations | Raman does not replace trace metal determination (Fe, Ca, Na) by methods such as ICP or AAS |
What this means for your process
If you produce or package AdBlue/DEF, inline measurement allows you to confirm the ISO 22241 concentration window and batch homogeneity at filling, reducing the risk of off-spec batches and producer liability.
The most reliable path to verification is a short feasibility study on real samples.
