EPA Method 1664A N-Hexane Extractable Material (HEM; Oil and Grease) and Silica Gel Treated N-Hexane Extractable Material (SGT-HEM; Non-polar Material) by Extraction and Gravimetry (Method 1664A; the Method)
Will measure the extractable material, i.e. oils, greases, etc. It is used specifically for wastewater analyses and was developed as a replacement method when CFCs were banned.
Thus, depending upon your application, i.e. if you are just looking for the amount of a particular "oil" in the water - the answer is that this method is going to measure what is extracted by the n-hexane.
If you are trying to look at "intrained water" such as oil in produced waters, desalter water, or other process type water - then you really need to be looking at other methods. There is a chapter by M. Yang - M. Yang (B)
TUV NEL Ltd, Scottish Enterprise Technology Park, East Kilbride, Glasgow G75 0QF, UK
K. Lee, J. Neff (eds.), Produced Water, DOI 10.1007/978-1-4614-0046-2_2, 57
C Springer Science+Business Media, LLC 2011 That looks at methods for oil in produced waters. There are also a number of vendors that produce analyzers that can do this "online"
