Carbon nanotube-passive samplers as novel tools for sampling and determining micropollutants in the aquatic environment

Passive sampling is an interesting and cost-effective strategy for the quantification of micropollutants in the aquatic environment. When combined especially with a sensitive analytical method such as liquid chromatography coupled with triple quadrupole mass spectrometry (LC-MS/MS), the use of passive sampling devices (PSDs) enables long-term and reliable determination of a wide range of chemicals. In this study, carbon nanotubes (CNTs) were used as an innovative sorbent in POCIS-like samplers (Polar Organic Chemical Integrative Sampler). The developed CNTs-PSDs were calibrated by the flow-through method and the obtained sampling rates (Rs) of analytes were compared with the previously obtained Rs values using the semi-static method. Subsequently, passive samplers were placed in the Baltic Sea, the Nogat River, and the Sztumskie Pole Lake in order to sample and concentrate 28 chemical com-pounds belonging to the group of contaminants of emerging concern (CECs). For the first time, the effectiveness of the use of CNTs-PSDs in the field was proven by the quantification of carbamazepine, diclofenac, p-nitrophenol, bisphenol A, 3,5-dichlorophenol, 17-beta-estradiol, 17-alpha-ethinylestradiol and metoprolol in the tested surface waters. The obtained time-weighted average (TWA) concentrations of analytes ranged from 0.22 +/- 0.12 ng/L (for metoprolol in the Nogat River) to 32.1 +/- 2.4 ng/L (for bisphenol A in the Sztumskie Pole Lake). More importantly, CNTs-PSDs determined a greater amount of micropollutants than grab sampling and solid-phase extraction (SPE), which proves the advantage of passive sampling over grab sampling, especially when monitoring contaminants in the aquatic envi-ronment at low concentration levels.

Automated summary

Passive sampling is a cost-effective strategy for quantifying micropollutants in water environments. In this study, carbon nanotubes were used as sorbents in POCIS-like samplers, and their effectiveness in field sampling was proven. The use of CNTs-PSDs allowed for the determination of various chemicals in surface waters.