On offshore production platforms, these are typically found after the final oil / water separation phase and prior to the produced water discharge.
Arjay Engineering offers both on-line and benchtop monitors for mg/l (ppm) oil in water analysing.
For online, the HydroSense 2410 is the model of choice. Using a fluorescence technology, this unit selectively targets petroleum hydrocarbons in the water.
Its non-contacting sample flow-through design tolerates turbidity, while providing a high degree of accuracy.
For benchtop, the FluoroCheck allows screening of field samples prior to using the ISO / EPA solvent extraction approach, which correlates well with lab and regulatory Methods.