Analytical Determination of Emerging Contaminants in Surface and Groundwater of the Hadejia-Jama’are River Basin, Jigawa State: Occurrence, Fate, and Risk Characterisation

The Hadejia-Jama'are wetland system in Jigawa State, North West Nigeria, supports extensive agricultural irrigation and provides drinking water to numerous communities, yet systematic screening for emerging contaminants including pharmaceuticals, personal care products, and pesticide metabolites is absent from published literature. This study analytically determines the occurrence of selected emerging contaminants in surface water and shallow groundwater across 12 sampling sites in the Hadejia-Jama'are River Basin. Target analytes include trimethoprim, sulfamethoxazole, ibuprofen, carbamazepine, triclosan, and atrazine metabolites. Solid-phase extraction combined with ultra-performance liquid chromatography-tandem mass spectrometry was used for analysis, with method detection limits in the low nanogram-per-litre range. Environmental fate modelling using the simple treatment model and bioconcentration factors for selected fish species was conducted. Ecological risk quotients for sensitive aquatic organisms were calculated from measured environmental concentrations. Results reveal widespread occurrence of sulfamethoxazole and trimethoprim at concentrations of 38 to 890 nanograms per litre, consistent with veterinary and human antibiotic use in the catchment. Ibuprofen and carbamazepine were detected in 75 percent of surface water samples. Atrazine metabolites in groundwater indicated legacy contamination. Risk quotients for sulfamethoxazole exceeded one for sensitive algal species at three sites. The study establishes baseline occurrence data and recommends integration of emerging contaminant monitoring into the national water quality surveillance framework. Keywords: emerging contaminants, Hadejia-Jama'are, pharmaceuticals, mass spectrometry, ecological risk