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Optimisation of headspace solid phase microextraction for the analysis of polychlorinated biphenyls and organochlorine pesticides in human milk samples
Abstracts / Toxicology Letters 280S (2017) S291–S293
consumption and fast analysis. However, actual microfluidic systems lack the ability to combine synthesis, separation and biological activity monitoring of compounds. In this context, we developed an integrated microfluidic system for chemical synthesis of small molecular compounds, their continuous separation as well as cell-based detection via bioelectronic real time monitoring. The major challenge to achieve this goal represents the connection of these three modules on a single chip and the optimization of each step of the different processes despite their diverse prerequisites and running conditions. We used human cell models in combination with microelectrode array-based impedance spectroscopy which is a highly sensitive technique that allows a quantitative detection of effects on cells. Preliminary results show the feasibility of combining microfluidic structures and microelectrode arrays for impedance spectroscopy on chip. Using human cell lines, we successfully established culturing conditions suitable for the requirements on a microfluidic chip concerning the direct online recording of small molecular compounds regarding their efficacy or toxicity. Thus, our device is a benefit for a synchronous drug synthesis, discovery and fast lead compound and toxicological screening. This lab-on-chip is a technical highlight representing a flexible system combining compound synthesis, separation and biological activity or toxicity testing. http://dx.doi.org/10.1016/j.toxlet.2017.07.821 P-09-04-06 Optimisation of headspace solid phase microextraction for the analysis of polychlorinated biphenyls and organochlorine pesticides in human milk samples Irena Brˇcic´ Karaˇconji 1 , Andreja Juriˇc 1 , Nataˇsa Brajenovic´ 1 , Darija Klinˇcic´ 1 , Snjeˇzana Herceg Romanic´ 1 , Marijana Matek Saric´ 2 1
Institute for Medical Research and Occupational Health, Zagreb, Croatia 2 University of Zadar, Zadar, Croatia Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are persistent environmental pollutants that raise concern
S293
due to their endocrine disrupting, immunotoxic, and neurotoxic properties. Owing to their lipophilic character, they are easily bioaccumulated. Breast milk is a significant source of exposure to these chemicals. A simple and rapid headspace solid phase microextraction (HSSPME) technique followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the simultaneous determination of 21 PCBs and 7 OCPs in human milk samples. The parameters affecting extraction efficiency were simultaneously optimised by experimental design. The best results were obtained using polydimethylsiloxane/divinylbenzene fibre, 0.5 g NaCl added to 1 mL of sample, extraction at 80 ◦ C (40 min), stirring at 300 rpm, and desorption at 260 ◦ C (10 min). The method showed a linear response within the tested concentration range (0.5–20 g/L), good precision (RSD < 10%), accuracy (average 95%), and sensitivity (limit of detection from 0.2 to 2.5 g/L). The method was applied for the analysis of 30 human milk samples. The most abundant PCBs were 138, 153, 170 and 180. Among the OCPs, p,p -DDE was the prevalent compound. An overall evaluation of the analytical parameters showed that HS-SPME combined with acquisition in MS/MS mode provides satisfactory sensitivity and selectivity that could replace the time consuming conventional clean-up processes based on liquid–liquid/solid-phase extraction. This work was financially supported by Project No. 8366 funded by the Croatian Science Foundation. http://dx.doi.org/10.1016/j.toxlet.2017.07.822
consumption and fast analysis. However, actual microfluidic systems lack the ability to combine synthesis, separation and biological activity monitoring of compounds. In this context, we developed an integrated microfluidic system for chemical synthesis of small molecular compounds, their continuous separation as well as cell-based detection via bioelectronic real time monitoring. The major challenge to achieve this goal represents the connection of these three modules on a single chip and the optimization of each step of the different processes despite their diverse prerequisites and running conditions. We used human cell models in combination with microelectrode array-based impedance spectroscopy which is a highly sensitive technique that allows a quantitative detection of effects on cells. Preliminary results show the feasibility of combining microfluidic structures and microelectrode arrays for impedance spectroscopy on chip. Using human cell lines, we successfully established culturing conditions suitable for the requirements on a microfluidic chip concerning the direct online recording of small molecular compounds regarding their efficacy or toxicity. Thus, our device is a benefit for a synchronous drug synthesis, discovery and fast lead compound and toxicological screening. This lab-on-chip is a technical highlight representing a flexible system combining compound synthesis, separation and biological activity or toxicity testing. http://dx.doi.org/10.1016/j.toxlet.2017.07.821 P-09-04-06 Optimisation of headspace solid phase microextraction for the analysis of polychlorinated biphenyls and organochlorine pesticides in human milk samples Irena Brˇcic´ Karaˇconji 1 , Andreja Juriˇc 1 , Nataˇsa Brajenovic´ 1 , Darija Klinˇcic´ 1 , Snjeˇzana Herceg Romanic´ 1 , Marijana Matek Saric´ 2 1
Institute for Medical Research and Occupational Health, Zagreb, Croatia 2 University of Zadar, Zadar, Croatia Polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) are persistent environmental pollutants that raise concern
S293
due to their endocrine disrupting, immunotoxic, and neurotoxic properties. Owing to their lipophilic character, they are easily bioaccumulated. Breast milk is a significant source of exposure to these chemicals. A simple and rapid headspace solid phase microextraction (HSSPME) technique followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed for the simultaneous determination of 21 PCBs and 7 OCPs in human milk samples. The parameters affecting extraction efficiency were simultaneously optimised by experimental design. The best results were obtained using polydimethylsiloxane/divinylbenzene fibre, 0.5 g NaCl added to 1 mL of sample, extraction at 80 ◦ C (40 min), stirring at 300 rpm, and desorption at 260 ◦ C (10 min). The method showed a linear response within the tested concentration range (0.5–20 g/L), good precision (RSD < 10%), accuracy (average 95%), and sensitivity (limit of detection from 0.2 to 2.5 g/L). The method was applied for the analysis of 30 human milk samples. The most abundant PCBs were 138, 153, 170 and 180. Among the OCPs, p,p -DDE was the prevalent compound. An overall evaluation of the analytical parameters showed that HS-SPME combined with acquisition in MS/MS mode provides satisfactory sensitivity and selectivity that could replace the time consuming conventional clean-up processes based on liquid–liquid/solid-phase extraction. This work was financially supported by Project No. 8366 funded by the Croatian Science Foundation. http://dx.doi.org/10.1016/j.toxlet.2017.07.822