Inorganic trace elements

From 2012 to 2022, silicon (Si) content in diesel averaged 0.4 mg/kg (a maximum value of 2.2 mg/kg was found in 2012 in Arequipa), with an average 0.1 mg/kg for zinc (Zn) content (a maximum value of 0.4 mg/kg was found in 2012 in Arequipa). Iron (Fe) content averaged 0.2 mg/kg, with a maximum value of 1.6 mg/kg found in 2012 in Arequipa. Most of the values are below the maximum limit of 1 mg/kg recommended by the Worldwide Fuel Charter (WWFC) for trace elements. These contaminants can lead to deposits in the engine, especially on the injectors. Silicon is not a natural component of diesel, hence the high Si values may indicate physical contamination caused by sand, dirt or dust infiltration at terminals or retail stations, although it could also be an anti-foam sil