The York Research Database

Detection and characterisation are two of the major challenges in understanding the fate, behaviour and occurrence of engineered nanoparticles (ENPs) in the natural environment. In a previous paper we described the development of hydrodynamic chromatography coupled to plasma mass spectrometry (HDC-ICP-MS) for detecting and characterising ENPs in aqueous matrices. This paper describes the applicability of the approach, to study the behaviour of silver nanoparticles in a much more complex and relevant environmental system i.e. sewage sludge supernatant. Batch sorption studies were performed at a range of nanosilver concentrations. Following completion, the sludge supernatant was characterised by ICP-MS, HDC-ICP-MS and transmission electron microscopy (TEM). It was found that, after a contact time of 6 h, most of the silver had partitioned to the sewage sludge (>90%). However, of the silver remaining in the supernatant, some of this was in the nanoparticle form, implying that closer consideration should be given to the longer-term impact of the release of silver ENPs into aquatic ecosystems. These preliminary data clearly show the utility of HDC-ICP-MS for studying the occurrence and behaviour of ENPs in complex natural environments.