There are several similarities between these international studies. They all employ grab sampling techniques for surface water samples and all focus on chemical concentrations in the aqueous phase. Yet sorption to sediments is recognized to be important in CECs in freshwater systems. Another similarity is that all the samples are spiked after transportation to the lab and not on site, and therefore will not account for any analyte losses during transport. Two of the studies filter before spiking with internal standards, which could result in unaccounted losses of a fraction of the target analytes . Furthermore, only one of the other studies has opted to transport samples on solid phase extraction (SPE) cartridges (R. R. . The other studies transport samples as liquids, and none have specified if the temperature of the samples were recorded on arrival. This paper proposes a new in-situ multi-mode extraction (iMME) sampler utilizing polymeric and glass fibre filters for multiresidue analysis of 105 CECs. The CECs in two contrasting rivers were selected, the largely urbanized River Avon (UK) and remotely positioned Olifants River in Kruger National Park (South Africa). The objective being to overcome limitations of analyte stability during sampling and transport. This is of importance in the international context and to enable sampling in remote locations where there is no access to the cold chain. This approach is also cost effective as it allows for the extraction of >100 compounds (and potentially many more) within one extraction protocol. An important consideration with regards to antimicrobial resistance (AMR) is the analysis of chemical antimicrobial agents (AAs) but also the analysis of biological targets, such as antimicrobial resistance genes (ARGs). Monitoring environmental levels of ARGs is important for monitoring spread of resistance and the scale of the problem . Furthermore, low levels of particular AAs in an environment may be identified as a low concern, however low levels of certain AAs could be as a result of high levels of resistance in the bacterial communities that are present. The River Avon was therefore also investigated for six ARGs using the iMME sampler to link to AAs reported in this study, and to explore the potential of on-site sampling for both chemicals and genes with this sampler.