I need to detect the presence of chlorine in used Engine oil. Based on the result, I can decide if need to move it to storage tank or if chlorine content found, then move to a separate tank.

 

There are a number of industrial oil testers that are traceable to ASTM Standards and can be calibrated.,

The most common measure the Total Base Number and Total Acid Number.

Chlorides are evidently found only in certain refrigerant oils due to the refrigerant breakdowns.

Summaries are in

http://labinspection.com/total base number.html

http://www.labinspection.com/total acid number.html