Occurrence of high production volume chemicals and polycyclic aromatic hydrocarbons in urban sites close to industrial areas. Human exposure and risk assessment.

Evaluating the occurrence of high production volume chemicals (HPVCs) and polycyclic aromatic hydrocarbons (PAHs) in the air is important because they carry a carcinogenic risk and can lead to respiratory or endocrine problems. Examples of HPVCs are organophosphate esters, benzosulfonamides, benzothiazoles, phthalate esters (PAEs), phenolic antioxidants and ultraviolet stabilizers. In this paper we develop a multi-residue method for determining HPVCs and PAHs in air samples via pressurized liquid extraction followed by gas chromatography-mass spectrometry. Air samples were collected by active sampling with high volume samplers using quartz fiber filter for the particulate matter (PM10) and polyurethane foams for gas phase. The compounds found at the highest concentrations were PAEs, with a concentration of up to 24 ng m-3 of DEHP in gas phase and up to 109 ng m-3 of DEHA in PM10. Non-carcinogenic risk assessment results ranged from 9.7E-05 to 9.5E-03 for most of the compounds studied. On the other hand, the results for carcinogenic risk showed that PAHs made the highest contribution.

Evaluation of air quality in indoor and outdoor environments: Impact of anti-COVID-19 measures.

This study monitors the presence of 88 volatile organic compounds (VOCs) and semi-volatile organic compounds (semi-VOCs) at the gas phase of seven indoor settings in a school in the city of Tarragona, Spain, and five outdoor locations around the city. The VOCs and semi-VOCs monitored were solvents (∑Solvents), aldehydes (∑Aldehydes), emerging organic compounds (∑EOCs), and other VOCs and semi-VOCs (∑Others). Passive sampling campaigns were performed using Carbopack X tubes followed by thermal desorption coupled to gas chromatography with mass spectrometry (TD-GC-MS). Overall, 70 of the target compounds included in the method were determined in the indoor air samples analysed, and 42 VOCs and semi-VOCs in the outdoor air samples. Our results showed that solvents were ubiquitous throughout the school at concentrations ranging from 272 µg m-3 to 423 µg m-3 and representing 68%-83% of total target compounds (∑Total). The values of ∑Total in 2021 were three times as high as those observed at the same indoor settings in 2019, with solvents experiencing the greatest increase. A plausible explanation for these observations is the implementation of anti-COVID-19 measures in the indoor settings, such as the intensification of cleaning activities and the use of hydroalcoholic gels as personal hygiene. The ∑Total values observed in the indoor settings evaluated were twenty times higher than those found outdoors. ∑Solvents were the most representative compounds found indoors (74% of the ∑Total). The concentrations of VOCs and semi-VOCs observed in the outdoors were strictly related to combustion processes from automobile traffic and industrial activities, with ∑Others contributing 58%, ∑Solvents 31%, and ∑Aldehydes 11% of the ∑Total. EOCs, on the other hand, were not detected in any outdoor sample.

Presence of emerging organic contaminants and solvents in schools using passive sampling.

In this study, we report on the applicability of passive sampling with Carbopack X adsorbent tubes followed by thermal desorption gas-chromatography-mass spectrometry (TD-GC-MS) to monitor the concentrations of emerging organic contaminants (EOCs) and solvents in ten indoor environments in a conventional and a vocational training school. However, if passive sampling is to be used as a reliable sampling technique, a specific diffusive uptake rate is required for each target compound. Accordingly, the aim of the present study was twofold. The first was to determine the experimental diffusive uptake rates of the target EOCs and solvents in one of the sampling sites of the vocational training school using Carbopack X adsorbent tubes and active sampling as the reference technique. The results showed experimental diffusive uptake rates between 0.46 mL min-1 and 0.94 mL min-1 with RSD % below 5% for the 28 target compounds. The second was to apply the uptake rates obtained experimentally to determine EOCs and solvents in schools. The monitoring results showed that solvents were ubiquitous throughout the conventional school with a concentrations range between 51.93 µg m-3 and 164.6 µg m-3, while EOCs were detected to a lesser extent. Moreover, the concentrations of EOCs in the vocational training school were much higher than those in the conventional school with concentrations of up to 562.9 µg m-3 for solvents and 344.3 µg m-3 for acrylate polymer monomers. After actively sampling for seven days in each school, we concluded that the concentrations of EOCs and solvents found are mostly linked to cleaning products (conventional school) and the activities carried out in the classroom (vocational training school).

Passive sampling to control air quality in schools: Uptake rate determination and application.

In this paper, we provide a detailed description of the application of passive sampling with Carbopack X tubes followed by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) to determine the concentrations of volatile organic compounds (VOCs) in different school environments. The main objective of the study was to monitor VOCs in seven indoor and three outdoor environments at a school in Tarragona, Spain. However, in order to obtain more accurate information, it was necessary to determine the experimental diffusive uptake rates of the target VOCs in indoor settings through parallel passive and active sampling in one classroom. The results showed experimental diffusive uptake rates in the range of 0.38 mL min-1 and 0.95 mL min-1 with RSD % below 5% for up to 44 VOCs. The monitoring results showed that ethanol (23.84-83.16 µg m-3 ) and isopropyl alcohol (5.42-25.92 µg m-3 ) were the most common compounds found in indoor environments, with cleaning products as the main emission source. The VOCs i-pentane and n-pentane were found at the highest concentrations in the three sampling sites set in the school's playground, and their concentrations were strictly related to combustion processes from automobile traffic.

Occurrence and risk assessment of benzothiazole, benzotriazole and benzenesulfonamide derivatives in airborne particulate matter from an industrial area in Spain.

In this study we monitored benzothiazole (BTHs), benzotriazole (BTRs) and benzenesulfonamide (BSAs) derivatives in airborne particulate matter from four sampling sites near the port of Tarragona (Spain) over a one-year period. To do so, we developed a method based on ultrasound-assisted solvent extraction (USAE) followed by gas chromatography-mass spectrometry (GC-MS). We also studied concentrations of NO2 and airborne particulate matter (PM2.5 and PMcoarse) for a year. Our results showed NO2 and PM2.5 concentrations below the maximum average values established by the Europen Directive 2008/50/EC in the zone under study. Moreover, NO2 values are directly proportional to changes in weather conditions and traffic emissions, while PMcoarse and PM2.5 concentrations do not follow a clear trend as these may be generated from multiple sources (loading and unloading activities and traffic emissions). Regarding BTHs, BTRs and BSAs concentrations in particulate matter, the compounds found at the highest concentrations were 1-H-benzothiazole, 2-methylbenzothiazole, 2-chlorobenzothiazole, 1-H-benzotriazole, 4-methyl-1-H-benzotriazole, 2-(methylthio)-benzothiazole, 5-methyl-1-H-benzotriazole and bromobenzenesulfonamide with average concentrations ranging from 0.19 to 1.54 ng m-3 in PMcoarse and from 0.09 to 0.61 ng m-3 in PM2.5. The remaining compounds were below the method quantification limits (MQLs) or were undetected in the samples analysed. Health risk values associated with the inhalation of the studied compounds were between 1.80 × 10-3 and 1.27 × 10-2 in the worst-exposure scenario.

Passive sampling of volatile organic compounds in industrial atmospheres: Uptake rate determinations and application.

This study describes the implementation of a passive sampling-based method followed by thermal desorption gas-chromatography-mass spectrometry (TD-GC-MS) for the monitoring of volatile organic compounds (VOCs) in industrial atmospheres. However, in order to employ passive sampling as a reliable sampling technique, a specific diffusive uptake rate is required for each compound. Accordingly, the aim of the present study was twofold. First, the experimental diffusive uptake rates of the target VOCs were determined under real industrial air conditions using Carbopack X thermal desorption tubes, and active sampling as reference method. The sampling campaigns carried out between October 2017 and May 2018 provided us of experimental diffusive uptake rates between 0.40 mL min-1 and 0.70 mL min-1 and stable over time (RSD % < 8%) for up to 41 VOCs. Secondly, the uptake rates obtained experimentally were applied for the determination of VOCs concentrations at 16 sampling sites in the North Industrial Complex of Tarragona. The results showed i-pentane, n-pentane and the compounds known as BTEX as the most representative ones. Moreover, some sporadic peaks of 1,3-butadiene, acrylonitrile, ethylbenzene and styrene resulting from certain industrial activities were detected.

New approach to resolve the humidity problem in VOC determination in outdoor air samples using solid adsorbent tubes followed by TD-GC-MS.

This study describes the humidity effect in the sampling process by adsorbent tubes followed by thermal desorption and gas chromatography-mass spectrometry (TD-GC-MS) for the determination of volatile organic compounds (VOCs) in air samples and evaluates possible solutions to this problem. Two multi-sorbent bed tubes, Tenax TA/Carbograph 1TD and Carbotrap B/Carbopack X/Carboxen 569, were tested in order to evaluate their behaviour in the presence of environmental humidity. Humidity problems were demonstrated with carbon-based tubes, while Tenax-based tubes did not display any influence. Silica gel, a molecular sieve and CaCl2 were tried out as materials for drying tube to remove air humidity, placed prior to the sampling tube to prevent water from entering. The pre-tubes filled with 0.5g of CaCl2 showed the best results with respect to their blanks, the analytes recoveries and their ability to remove ambient humidity. To avoid the possible agglomeration of CaCl2 during the sampling process in high relative humidity atmospheres, 0.1g of diatomaceous earth were mixed with the desiccant agent. The applicability of the CaCl2 pre-tube as drying agent prior to Carbotrap B/Carbopack X/Carboxen 569 tubes was tested in urban and industrial locations with samplings of air at high relative humidity. In addition, the results were compared with those obtained using Tenax TA/Carbograph 1TD tubes.

Degradation of synthetic fragrances by laccase-mediated system.

Laccase mediator systems are important biodegradation agents as the rate of reaction could be enhanced in the presence of redox mediators. In the present study the commercial enzyme laccase from Trametes versicolor and the redox mediator 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were used for the biotransformation of the synthetic fragrances 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8,-tetramethyl-2-naphthyl)ethan-1-one (Iso-E-Super, OTNE), 1,3,4,6,7,8,-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[g]-2-benzopyran (Galaxolide, HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphtalene (Tonalide, AHTN) and the transformation product of HHCB, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[g]-2-benzopyran-1-one (Galaxolidone, HHCB-lactone) in water. A particular focus was to assess the effects of the enzyme laccase from Trametes versicolor in the enantioselective degradation of the target compounds, for this reason gas chromatography with an enantioselective column was used as separation technique followed by mass spectrometry detection. In addition, as enantioselective degradation of musk fragrances was observed in wastewater, sewage sludge and fish samples, enantiomeric fractions of selected compounds were studied during composting. In a period of 144h, the target fragrances could be effectively removed by the enzyme laccase with removal percentages greater than 70%, except AHTN with a removal percentage of 42%. However, the degradation process prompted by the enzyme laccase was shown to be non-enantioselective as no significant differences were observer between the enantiomeric fractions calculated at the beginning and at the end of the degradation process. Meanwhile, the composting process was shown to be enantioselective.

Comparative study of comprehensive gas chromatography-nitrogen chemiluminescence detection and gas chromatography-ion trap-tandem mass spectrometry for determining nicotine and carcinogen organic nitrogen compounds in thirdhand tobacco smoke.

Thirdhand tobacco smoke (THS) constitutes a poorly understood pathway of exposure of non-smokers, especially toddlers, to tobacco-related carcinogens. However, to date most of the carcinogens present in tobacco smoke have not been detected in THS and, therefore, the significance of THS health risk is still unknown. In this study, we have compared the performance of two analytical methods - one based on gas chromatography coupled to ion trap mass spectrometry detection (GC-IT-MS) and the other on comprehensive two-dimensional gas chromatography coupled to a nitrogen chemiluminescence detector (GC×GC-NCD) - for simultaneously determining, in settled house dust, the presence of 16 organic nitrogen carcinogens already detected in tobacco smoke. The target compounds included four aromatic amines, two nitrocompounds, eight N-nitrosamines and two tobacco-specific nitrosamines, as well as nicotine as a tobacco marker. Dust samples were extracted using in-cell clean up pressurized liquid extraction with silica as clean up sorbent and ethyl acetate as the organic solvent, with average recovery of 89%. Although GC-IT-MS, using chemical ionization with methanol and tandem MS, performed well, the optimized GC×GC-NCD gave lower limits of detection (from 4 to 22ngg(-1)) and better repeatability and reproducibility a low concentration levels (%RSD<8%) and, therefore, was applicable for determining these different groups of carcinogens without the need for derivatization prior to the GC analysis. The performance of the optimized PLE/GC×GC-NCD method was tested by quantifying the target compounds in house dust samples from smokers' and non-smokers' homes. The median carcinogen compounds detected was 3.8µgg(-1) and 1.1µgg(-1) in smokers' and non-smokers' house dust, respectively. In this study, we have detected highly carcinogenic aromatic amines and nitro compounds for the first time in settled house dust complementing the state of knowledge of THS composition and providing fresh evidence about THS health risks.

Influence of pre-treatment process on matrix effect for the determination of musk fragrances in fish and mussel.

Musk compounds are widely used as fragrances in personal care products. On account of their widespread use and their low biodegradation, they can be found in environmental samples. In our study two extraction methodologies were compared and different clean-up strategies were also studied in order to develop a reliable analytical method, with minimum matrix effect and good detection limits, to determine synthetic musk fragrances- six polycyclic musks, three nitro musks and the degradation product of one polycyclic musk- in fish and mussel samples. The first extraction technique involves a QuEChERS extraction, a consolidate extraction methodology in the field of food analysis of growing interest over recent years, followed by a dispersive solid-phase extraction (dSPE) as clean-up strategy. The second extraction technique consists of a conventional pressurised liquid extraction (PLE) with dichloromethane and an in-cell clean-up to decrease the matrix effect and remove the undesired components(⁎)present in PLE extracts. Large volume injection (LVI) followed by gas chromatography-ion trap-tandem mass spectrometry (GC-IT-MS/MS) was chosen as the separation and detection technique. Validation parameters, such as method detection limits and method quantification limits were found at ng g(-1) levels for both fish and mussel matrices. Good levels of intra-day and inter-day repeatabilities were obtained analysing fish and mussel samples spiked at 50 ng g(-1) (d.w.) (n=5, RSDs<17%). The developed PLE/GC-IT-MS/MS method was successfully applied to determine the target musk fragrances present in fish and mussel samples from the local market in Tarragona and fish samples from the Ebro River. The results showed the presence of galaxolide (2.97-18.04 ng g(-1) (d.w.)) and tonalide (1.17-8.42 ng g(-1) (d.w.)) in all the samples analysed, while the remaining polycyclic musks such as cashmeran, celestolide and phantolide, were only detected in some of the fish samples analysed. None of the samples analysed contained detectable traces of the nitro musks studied.

Sorbent-packed needle microextraction trap for synthetic musks determination in wastewater samples.

A needle trap (NT) device filled with HF Bondesil-C18 as a sorbent material was evaluated for the dynamic headspace analysis of a family of nine synthetic musks compounds that include two nitro musks, six polycyclic musks (with galaxolide and tonalide as the most widespread used polycyclic musks) and the degradation product of galaxolide (galaxolidone) in wastewater samples. Different parameters affecting the adsorption capacity of the sorbent were studied (e.g. extraction mode, extraction temperature, salt concentration, preincubation time fill and ejection speed or fill volume). Furthermore, injection parameters used with the NT device (e.g. desorption mode, desorption temperature and time) were evaluated to optimize the desorption and transfer of the target compounds into the GC column. Method detection limits obtained with gas chromatography-tandem mass spectrometry (GC-MS/MS) detection were found in the low ng L(-1) range, between 2.5 and 10 ng L(-1), depending on the target compounds. Moreover, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in wastewater samples with relative standard deviations (n=5, 100 ng L(-1)) less than 11 and 17%, respectively. The developed method was satisfactorily applied to the analysis of aqueous samples obtained from three wastewater treatment plants. All the polycyclic musks studied were detected in influent samples with cashmeran, galaxolide and tonalide as the most representative compounds. The analysis of effluent wastewater showed a decrease in the concentrations of all of the polycyclic musk detected in influent samples and an increase in the concentration of galaxolidone until a maximum value of 820 ng L(-1).

On-line coupling of solid-phase extraction to gas chromatography-mass spectrometry to determine musk fragrances in wastewater.

An on-line coupling solid-phase extraction (SPE) has been developed for the first time to preconcentrate trace amounts of 17 musk fragrances extensively used in personal care products (6 polycyclic musks, 3 nitro musks, 7 macrocyclic musks and 1 polycyclic musk degradation product) from wastewater samples, prior to analysis by gas chromatography and mass spectrometry through an on-column interface. A 10 mm × 2 mm I.D. precolumn packed with Oasis HLB (60 µm) or C18 (60 µm) was compared for the optimization of the solid-phase extraction process. The parameters affecting the transfer of the analytes from the precolumn to the GC system (e.g. flow-rate, temperature and solvent vapor exit time) as well as SPE parameters (e.g. sample flow, sample volume, elution solvent, etc.) were optimized. An organic modifier such as methanol was added to the sample before the extraction process to avoid adsorption problems. The use of the MS detector under selected ion monitoring acquisition enabled the analytes to be quantified at low ng L(-1) levels, preconcentrating only 10 mL of sample, and the limits of detection were between 1 and 30 ng L(-1). The method was applied for the determination of musk fragrances in wastewater samples from three urban wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed that galaxolide, tonalide and ambrettolide were the most abundant musk compounds with concentrations ranging between 18 ng L(-1) and 45,091 ng L(-1), 852 ng L(-1) and 49,904 ng L(-1) and 507 ng L(-1) and 21,528 ng L(-1) respectively. The remaining musks were present at lower concentrations and two of the macrocyclic musk studied (musk MC4 and civetone) were not detected. The analysis of effluent wastewater showed a decrease in the concentrations of all of the compounds present in influent samples, with the decrease being more significantly in the case of polycyclic and nitro musks than for macrocyclic musks. Only HHCB-lactone remained constant or increased its concentration.

Headspace stir bar sorptive extraction followed by thermal desorption and gas chromatography with mass spectrometry to determine musk fragrances in sludge samples without sample pretreatment.

A direct, simple and solvent-free method based on headspace stir bar sorptive extraction and thermal desorption gas chromatography with mass spectroscopy was developed to determine 13 musk fragrances (six polycyclic musks, three nitro musks and four macrocyclic musks) in sludge without sample treatment. The optimal headspace stir bar sorptive extraction conditions were achieved when a polydimethylsiloxane stir bar was exposed for 45 min in the headspace of a 10 mL vial filled with 100 mg of sludge mixed with 0.2 mL of water stirred at 750 rpm at 80°C. The stir bar was then desorbed in the thermal desorption gas chromatography and mass spectrometry system, obtaining limits of detection between 5 and 30 ng/g. The method applicability was tested with sewage sludge from two urban wastewater treatment plants and from a potable water treatment plant. Results showed galaxolide and tonalide to be the most abundant musk fragrances found in wastewater treatment plants with maximal concentrations of 9240 and 7500 ng/g, respectively. Maximum concentration levels between 35 and 635 ng/g were found for musk ketone, musk moskene, traseolide, phantolide and celestolide in this kind of samples. Concentrations below the limits of quantitation of phantolide, galaxolide, tonalide and musk ketone were found in sludge from a potable water treatment plant.

An automated headspace solid-phasemicroextraction followed by gas chromatography­mass spectrometry method to determine macrocyclic musk fragrances in wastewater samples.

A fully automated method has been developed for determining eight macrocyclic musk fragrances in wastewater samples. The method is based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography­mass spectrometry (GC-MS). Five different fibres (PDMS 7 µm, PDMS 30 µm, PDMS 100 µm, PDMS/DVB 65 µm and PA 85 µm) were tested. The best conditions were achieved when a PDMS/DVB 65 µm fibre was exposed for 45 min in the headspace of 10 mL water samples at 100 °C. Method detection limits were found in the low ng L−1 range between 0.75 and 5 ng L−1 depending on the target analytes. Moreover, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in wastewater samples with relative standard deviations (n =5, 1,000 ng L−1) less than 9 and 14 %, respectively. The applicability of the method was tested with influent and effluent urban wastewater samples from different wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed the presence of most of the target macrocyclic musks with, most notably, the maximum concentration of ambrettolide being obtained in WWTP A (4.36 µg L−1) and WWTP B (12.29 µg L−1), respectively. The analysis of effluent urban wastewater showed a decrease in target analyte concentrations, with exaltone and ambrettolide being the most abundant compounds with concentrations varying between below method quantification limit (

A simple and automated method to determine macrocyclic musk fragrances in sewage sludge samples by headspace solid-phase microextraction and gas chromatography-mass spectrometry.

For the first time, headspace solid-phase microextraction (HS-SPME) has shown to be a powerful technique to extract macrocyclic musk fragrances directly from sewage sludge. It avoids the need to use additional extraction/preconcentration techniques or clean-up procedure and facilitates the automation of the method. Thus, a simple and fully automated method based on HS-SPME and GC-MS has been developed which allows the determination of eight macrocyclic musk fragrances at ngg(-1) (d.w.) levels. The optimal HS-SPME conditions were achieved when a PDMS/DVB 65µm fibre was exposed for 45min in the headspace of 0.25g sewage sludge samples mixed with 0.5mL of water stirred at 750rpm at 80°C. Optimal desorption conditions were found to be 250°C for 3min. Method detection limits were found in the low pgg(-1) range between 10pgg(-1) (d.w.) and 25pgg(-1) (d.w.) depending on the target analytes. In addition, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in sewage sludge with relative standard deviations varying between 1% to 9% and 6% to 15% respectively (n=5, 1000pgg(-1) d.w.). The applicability of the method was tested with sewage sludge from three urban sewage treatment plants (STPs). The analysis revealed the presence of the macrocyclic musks studied in several samples, with concentrations ranging between below MQL (method quantification limit) and 0.89ngg(-1) (d.w.).

Fully automated determination of macrocyclic musk fragrances in wastewater by microextraction by packed sorbents and large volume injection gas chromatography-mass spectrometry.

A fully automated method has been developed for the determination of eight macrocyclic musk fragrances in urban wastewater. The procedure includes the enrichment of the analytes by microextraction by packed sorbent (MEPS) followed by large volume injection-gas chromatography-mass spectrometry (LVI-GC-MS). The main factors in the MEPS technique were optimized. For all of the analytes, the highest enrichment factors were achieved when 4 mL samples were extracted by using C18 MEPS-sorbent and 50 µL of ethyl acetate were used for desorption. The eluate was directly analysed by GC-MS. Detection limits were found to be between 5 ng L(-1) and 10 ng L(-1), depending on the target analytes. In addition, under optimized conditions, the method gave good levels of intra-day and inter-day repeatability in wastewater samples with relative standard deviation (RSD) (n=3, 1,000 ng L(-1)) less than 5% and 9%, respectively. The applicability of the method was tested with wastewater samples from two influent and effluent urban wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed the presence of most of the macrocylic musks at concentrations higher than the method quantification limits (MQLs), being the most abundant analyte ambrettolide at 9.29 µg L(-1). In addition, the analyses of effluent urban wastewater showed a decrease in the concentrations with macrocyclic musk concentrations of between not detected (n.d.) and 2.26 µg L(-1) being detected.

Determination of musk fragrances in sewage sludge by pressurized liquid extraction coupled to automated ionic liquid-based headspace single-drop microextraction followed by GC-MS/MS.

A method for the quantitative determination of ten musk fragrances extensively used in personal care products from sewage sludge was developed by using a pressurized liquid extraction (PLE) followed by an automated ionic liquid-based headspace single-drop microextraction and gas chromatography-tandem mass spectrometry. The influence of main factors on the efficiency of PLE was studied. For all musks, the highest recovery values were achieved using 1 g of pretreated sewage sludge, H(2) O/methanol (1:1) as an extraction solvent, a temperature of 80°C, a pressure of 1500 psi, an extraction time of 5 min, 2 cycles, a 100% flush volume, a purge time of 120 s, and 1 g Florisil as in-cell clean-up extraction sorbent. The use and optimization of an in-cell clean-up sorbent was necessary to remove fatty interferents of the PLE extract that make the subsequent ionic liquid-based headspace single-drop microextraction difficult. Validation parameters, namely LODs and LOQs, ranged from 0.5-1.5 to 2.5-5 ng/g, respectively. Good levels of intra- and interday repeatabilities were obtained analyzing sewage sludge samples spiked at 10 ng/g (n = 3, RSDs < 10%). The method applicability was tested with sewage sludge from different wastewater treatment plants. The analysis revealed the presence of all the polycyclic musks studied at concentrations higher than the LOQs, ranging from 6 to 530 ng/g. However, the nitro musk concentrations were below the LOQs or, in the case of musk xylene, was not detected.

Fully automated ionic liquid-based headspace single drop microextraction coupled to GC-MS/MS to determine musk fragrances in environmental water samples.

A fully automated ionic liquid-based headspace single drop microextraction (IL-HS-SDME) procedure has been developed for the first time to preconcentrate trace amounts of ten musk fragrances extensively used in personal care products (six polycyclic musks, three nitro musks and one polycyclic musk degradation product) from wastewater samples prior to analysis by gas chromatography and ion trap tandem mass spectrometry (GC-IT-MS/MS). Due to the low volatility of the ILs, a large internal diameter liner (3.4 mm i.d.) was used to improve the ILs evaporation. Furthermore, a piece of glass wool was introduced into the liner to avoid the entrance of the ILs in the GC column and a guard column was used to prevent analytical column damages. The main factors influencing the IL-HS-SDME were optimized. For all species, the highest enrichments factors were achieved using 1 µL of 1-octyl-3-methylimidazolium hexafluorophosphate ([OMIM][PF(6)]) ionic liquid exposed in the headspace of 10 mL water samples containing 300 g L(-1) of NaCl and stirred at 750 rpm and 60 °C for 45 min. All compounds were determined by direct injection GC-IT-MS/MS with a chromatographic time of 19 min. Method detection limits were found in the low ng mL(-1) range between 0.010 ng mL(-1) and 0.030 ng mL(-1) depending on the target analytes. Also, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in wastewater samples with relative standard deviations varying between 3% and 6% and 5% and 11%, respectively (n=3, 1 ng mL(-1)). The applicability of the method was tested with different wastewater samples from influent and effluent urban wastewater treatment plants (WWTPs) and one potable treatment plant (PTP). The analysis of influent urban wastewater revealed the presence of galaxolide and tonalide at concentrations of between 2.10 ng mL(-1) and 0.29 ng mL(-1) and 0.32 ng mL(-1) and