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Among the various species of vegetation, conifers play an important role as a biomonitor of air pollution. The current study presents the determination of pesticides and polycyclic aromatic hydrocarbons in 15 conifer samples collected in August 2018 (summer season) from different regions in north Lebanon (Tripoli, Koura, Bcharre, and Akkar). Pollutants were extracted based on QuEChERS-SPME followed by liquid and gas chromatography-tandem mass spectrometry. Results showed that the samples collected from Bcharre region had the lowest concentration in both pesticides and polycyclic aromatic hydrocarbons with a total concentration of 50 and 66 ng g-1, while the samples collected from the regions widely known by their agriculture (Akkar, Tripoli, and Koura areas) were the most polluted with concentrations of 231 and 422 ng g-1, 192 and 370 ng g-1, and 127 and 98 ng g-1 for pesticides and polycyclic aromatic hydrocarbons respectively. This study revealed that conifers are suggested to be efficient biomonitors of contamination levels in the air.

In recent years, bees’ products (nectar, honey, beeswax, pollen) have been considered as potential biomonitors of air pollution. The efficacy of these matrices, especially honey, in environmental biomonitoring has been demonstrated in many studies to be due to its medicinal properties. A multiresidue method based on liquid–liquid extraction using ethyl acetate, followed by an analysis using liquid chromatography coupled with tandem mass spectrometry for the analysis of pesticides, was developed in this paper. Afterwards, the method was validated, and results showed that the intraday and interday relative standard deviation was below 5%, and the recoveries obtained generally ranged from 68% to 104%. Furthermore, the method showed high precision and sensitivity for all target compounds, with detection and quantification limits lower than 3 and 9 ng g−1, respectively. Residues from a range of pesticides were detected in each of the samples collected. Pesticide contamination was highest in samples collected from the Akkar and Koura area, which are both well known for their agricultural production. In contrast, samples obtained from Bcharre showed the lowest pesticide contamination. Finally, analysis of real honey samples collected from Lebanon shows the potentiality of honey as a biomonitor for assessing air pollution.

International audience; A new sensitive and selective analytical methodology to quantify glyphosate (GLY), aminomethylphosphonic acid (AMPA), and glufosinate (GLU) in both soil and earthworms (Allolobophora chlorotica) was developed. The extraction and purification methods were optimized. The samples were extracted with various aqueous solutions (HNO3, H2O, KOH and borate buffer) and derivatized with 9-Fluorenylmethyl chloroformate (FMOCCl). To optimize the extraction step, a method to remove the excess FMOCCl was applied based on liquid-liquid extraction with diethyl ether. The purification of derivatized extracts was carried out using XLB solid phase extraction (SPE) cartridges before internal standard quantification by liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS). The elution step was optimized to obtain the best recoveries possible, which was with acidic methanol (1% formic acid) (67% for GLY, 70% for GLU and 65% for AMPA). The extraction and purification method followed by analysis of the two herbicides and AMPA in soils using LC/MS/MS determined limit of quantification (LOQ) values of 0.030mug g(-)(1) for GLY, 0.025mug g(-)(1) for AMPA and 0.020microg g(-)(1) for GLU . For earthworms, LOQ were 0.23mug g(-)(1) for GLY, 0.20mug g(-)(1) for AMPA and 0.12mug g(-)(1) for GLU. . The developed method was applied to determine these compounds in natural soils and earthworms.

Among the various species of vegetation, conifers play an important role as a biomonitor of air pollution. The current study presents the determination of pesticides and polycyclic aromatic hydrocarbons in 15 conifer samples collected in August 2018 (summer season) from different regions in north Lebanon (Tripoli, Koura, Bcharre, and Akkar). Pollutants were extracted based on QuEChERS-SPME followed by liquid and gas chromatography-tandem mass spectrometry. Results showed that the samples collected from Bcharre region had the lowest concentration in both pesticides and polycyclic aromatic hydrocarbons with a total concentration of 50 and 66 ng g

International audience; The conifer is a natural vascular land plant composed of very particular leaves called needles that are able to accumulate, throughout years, a wide range of non-volatile, semi-volatile and volatile compounds of different structure and polarity such as pesticides and persistent organic pollutants. However, the extraction of these compounds from such matrix remains mainly uncommitted. In this paper, a QuEChERS based extraction procedure was developed for the concomitant extraction and analysis of 134 pesticides, 22 polychlorinated biphenyls and 16 polycyclic aromatic hydrocarbons residues from conifer needles. The method included a liquid-liquid extraction using acetonitrile (ACN) followed by a clean-up step using, Primary Secondary Amine (PSA), graphitized carbon black (GCB) and C18 particles, in the presence of salts. The obtained extracts were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) for their contamination by non-volatile pesticides. However, volatile pesticides, polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons were subjected to a concentration step using solid-phase microextraction (SPME) prior to their analysis by gas chromatography coupled to tandem mass spectrometry (GC–MS/MS). The method was developed and validated, and the obtained results revealed a recovery rate ranged between 60% and 121% for all the targeted compounds. In addition, the method showed high sensitivity and precision with detection and quantification limits less than 20 ng g−1 for most target compounds and low RSD for both inter and intra-day analysis. Once developed the method was applied on conifer samples collected from 15 different sites in northern Lebanon. The analysis of the collected samples showed a persistence of the different assessed pollutants depending of the characteristics of each site.

Organic-inorganic hybrid nano-building blocks of aromatic nitro-, aldehyde-, and bromo-functionalized polyhedral oligomeric silsesquioxanes were easily prepared through nucleophilic substitutions, starting from the reactions between octakis(3-chloropropyl)octasilsesquioxane and phenoxide derivatives. These phenoxide anions not only supply the substitution functions to a silsesquioxane cage, but can also induce a cage-rearrangement leading to the formation of octa-, deca-, and dodecahedral silsesquioxane cages.

Novel organic-inorganic hybrid nanobuilding blocks of methacrylate- and acrylate-functionalized polyhedral oligomeric silsesquioxanes were easily prepared via nucleophilic substitution on octakis(3-chloropropyl)octasilsesquioxane, using sodium methacrylate and sodium acrylate, respectively. From a practical standpoint, these cage-rearranged silsesquioxanes (T8, T10, and T12) could be readily isolated in their pure form with conventional silica gel column chromatography. Octakis(3-propyl methacrylate)octasilsesquioxane (T8) is a colorless, crystalline solid with a melting point of 66.7-67.2 °C, while other cage products are colorless viscous liquids at room temperature. Moreover, we report that the chemical structure/physical property relationship of silsesquioxane cages not only is dependent on the symmetry of the inorganic silsesquioxane core at a given temperature but also is dictated by the organic substituent mobility. Structures of the products were confirmed by (1)H, (13)C, and (29)Si NMR spectroscopy and high resolution electrospray ionization mass spectrometry analysis.