Nicotine derivatives in wastewater and surface waters: application as chemical markers for domestic wastewater

Abstract

Nicotine is extensively metabolized in the human body to a number of compounds, which may enter natural waters via discharge of domestic wastewater. However, little is known on exposure of and potential effects on the aquatic environment. In this study, two major urinary metabolites, cotinine and 3'-hydroxycotinine, as well as a further tobacco alkaloid, N-formylnornicotine, were measured in wastewater and water from Swiss lakes using an analytical procedure based on SPE and LC-MS/MS SRM with cotinine-d3 as internal standard (LOQs, 1.0-1.5 ng/L). Typical concentrations of cotinine and 3'-hydroxycotinine were approximately 1-10 microg/L in untreated wastewater, but clearly less in treated wastewater (approximately 0.01-0.6 microg/L), corresponding to elimination efficiencies of 90-99%. N-Formylnornicotine, however,was found at similar concentrations in untreated and treated wastewater (0.02-0.15 microg/L). Its apparent persistence during wastewater treatment was further confirmed by incubation experiments with activated sludge. In lakes, cotinine, 3'-hydroxycotinine, and N-formylnornicotine were detected at concentrations up to 15, 80, and 6 ng/L, respectively. Concentrations in lakes correlated with the expected anthropogenic burden by domestic wastewater (ratio population per water throughflow), demonstrating the suitability of these nicotine derivatives as hydrophilic, anthropogenic markers. In small receiving waters with significant wastewater discharges, concentrations of a few hundred ng/L may be expected. Possible ecotoxicological risks associated with such environmental concentrations, can, however, not be assessed at present as data on effects on aquatic organisms are very limited, in particular on long-term effects.