Aldehydes are organic compounds with a carbonyl group in their structure. In general, aldehydes are obtained by removing hydrogen ions from alcohols at elevated temperatures. The name of aldehyde comes from here. Numerous aromatic aldehydes are abundant in nature. For example, benzaldehyde in almonds, vanillin in vanilla and cinnamaldehyde in cinnamon. These aldehydes have their own unique fragrances. Aldehydes can easily participate in many chemical reactions. It is simply oxidized to form carboxylic acids and reduced to form alcohols. An aqueous solution of formaldehyde at a percentage of 40 is called formalin. Paraformaldehyde, a formaldehyde polymer, is used as insecticidal and antiseptic.

Gas chromatography (GC) is a widely used method in chemistry when analyzing or separating volatile substances and gases.

In the authorized laboratories, gas chromatography (GC) and aldehyde content determination studies are carried out within the scope of chemical tests and the standards published by domestic and foreign organizations and test methods and test criteria accepted worldwide are complied with. With these systematic and scientific studies carried out in laboratories, more reliable and unbiased service is provided. The following are a few standards that are based on the following studies:

• TS ISO 22241-1 Diesel engines - Nox reducing agent AUS 32 - Part 1: Quality requirements

This standard specifies the quality requirements for the NOx reducing agent AUS 32 (aqueous urea solution) used in converters operating on selective catalytic reduction (SCR) principle in diesel engine vehicles.

• TS ISO 22241-2 Diesel engines - Nox reducing agent AUS 32 - Part 2: Test methods

This standard covers the test methods used to determine the quality of the NOx reducing agent AUS 22241 (aqueous urea solution) specified in the ISO 1-32 standard. Annex F covers the criteria for the determination of aldehyde content.