The accurate and specific analysis of polymeric scale squeeze inhibitors requires that the analyst has access to a toolbox of methodologies from which the most suitable methodology can be chosen based on the operational considerations of the analysis. This is particularly important in the field of co-mingled wells in subsea and deepwater applications where there is a requirement to quantify a primary inhibitor in the presence of secondary and tertiary inhibitors – which may be either subsea or topside scale inhibitors. This has not been successfully demonstrated in commercial applications before now. This paper presents a number of advancements which have been made recently including a unique method which is now being implemented in the Norwegian North Sea and allows the accurate quantification of two chemical families of scale inhibitors in the presence of each other and in the presence of a third chemical family of topside inhibitors. This method uses mass spectrometry as the detection technique gives a much enhanced sensitivity and specificity; typically to sub 0.5ppm levels in field brine and has significant application potential in the field of co-mingled wells in subsea and deepwater environments to allow individual wells to be monitored.