Calcium in Lubricating Oil

While the ASTM Methods and Fed. Test Method use the same sample  for  determination  of  several  metals, the IP  Methods  is  specifically concerned with  calcium  analysis. This calls  for ashing  followed  by determination  of the  calcium  either  as oxide  or oxalate.

Chemical Analysis for Metals in Lubricating oils

These methods of chemical analysis are intended  for the  determination of barium, tin, silica, zinc, aluminum, calcium, magnesium, sodium and potassium in  new  and used  lubricating  oils. Other metallic elements, sulfur, phosphorus and  chlorine in  amounts  commonly  found  in lubricating  oils  do not  interfere in this  method.

Essentially,  the  method  consists  of  igniting  the sample, dissolving  the  residue  in  mineral acid and  then  separating  the various  metals by  conventional  methods.