Abstract: Persistent organic pollutants (POPs) can cause long term damage to the environment. Two classes of organic molecules have come to the attention of regulators and water treatment authorities in recent years; iodinated X-Ray contrast media (XCM) and artificial sweeteners (AS). These molecules, by design, have a high degree of stability. Aware of the increased abundance of these molecules in waste water, the IWB Water Laboratory set out to develop a robust, simple method to analyse levels of these molecules in water from the river Rhine, ground water and drinking water.