Analysis of selected benzodiazepines in the environment by HF-LPME and LC-MS/MS

Abstract

Industrial chemicals, pesticides and other similar compounds are all known to be a burden for the environment. In high concentrations they can all affect the biological environment in a manner that is dangerous for organisms. The presence of pharmaceuticals and personal care products (PPCPs) in the environment are of great interest regarding to their potential toxicity. Pharmaceuticals and PPCPs are discovered in soil, sludge, sewage and in the adjacent aquatic environment. The aim of this study was to develop and optimize a hollow fiber liquid- phase microextraction (HF-LPME) method for extraction and pre-concentration of benzodiazepines and its metabolites in sewage water. Different parameters like donor- and acceptor phases, fibers and organic phases were to be tested. The compounds that was to be investigated in this study were chosen by looking at sales statistics for benzodiazepines in Norway over a three years period, 2005-2007. Some metabolites of the compounds were also included. The chosen compounds were zopiclone, zopiclone-d8, zopiclone N-oxide, N-desmethyl zopiclone hydrochloride, zolpidem, zolpidem-d6, alprazolam, alprazolam 5-oxide, 1-hydroxy alprazolam, midazolam, midazolam- d5 and 1`-hydroxy midazolam. Later in the project clonazepam and 7-aminoclonazepam were included. Sewage water samples were collected at Langnes Sewage Treatment Plant (STP), Tromsø, before they were filtered and extracted by hollow fiber liquid phase microextraction and analysed on Ultra Performance Liquid Chromatography- Mass Spectrometry/ Mass Spectrometry (UPLC- MS/MS). Quantifiable amounds of zolpidem was found during the collection in January, midazolam and 1- hydroxyl midazolam were detectable. In April 1- hydroxy midazolam, midazolam and zolpidem were detectable.