Sub-5-min RP-UHPLC-TIMS for high-throughput untargeted lipidomics and its application to multiple matrices.

Untargeted lipidomics, with its ability to take a snapshot of the lipidome landscape, is an important tool to highlight lipid changes in pathology or drug treatment models. One of the shortcomings of most untargeted lipidomics based on UHPLC-HRMS is the low throughput, which is not compatible with large-scale screening. In this contribution, we evaluate the application of a sub-5-min high-throughput four-dimensional trapped ion mobility mass spectrometry (HT-4D-TIMS) platform for the fast profiling of multiple complex biological matrices. Human AC-16 cells and mouse brain, liver, sclera, and feces were used as samples. By using a fast 4-min RP gradient, the implementation of TIMS allows us to differentiate coeluting isomeric and isobaric lipids, with correct precursor ion isolation, avoiding co-fragmentation and chimeric MS/MS spectra. Globally, the HT-4D-TIMS allowed us to annotate 1910 different lipid species, 1308 at the molecular level and 602 at the sum composition level, covering 58 lipid subclasses, together with quantitation capability covering more than three orders of magnitude. Notably, TIMS values were highly comparable with respect to longer LC gradients (CV% = 0.39%). These results highlight how HT-4D-TIMS-based untargeted lipidomics possess high coverage and accuracy, halving the analysis time with respect to conventional UHPLC methods, and can be used for fast and accurate untargeted analysis of complex matrices to rapidly evaluate changes of lipid metabolism in disease models or drug discovery campaigns.

Enhanced selective capture of phosphomonoester lipids enabling highly sensitive detection of sphingosine 1-phosphate.

Sphingolipids play crucial roles in cellular membranes, myelin stability, and signalling responses to physiological cues and stress. Among them, sphingosine 1-phosphate (S1P) has been recognized as a relevant biomarker for neurodegenerative diseases, and its analogue FTY-720 has been approved by the FDA for the treatment of relapsing-remitting multiple sclerosis. Focusing on these targets, we here report three novel polymeric capture phases for the selective extraction of the natural biomarker and its analogue drug. To enhance analytical performance, we employed different synthetic approaches using a cationic monomer and a hydrophobic copolymer of styrene-DVB. Results have demonstrated high affinity of the sorbents towards S1P and fingolimod phosphate (FTY-720-P, FP). This evidence proved that lipids containing phosphate diester moiety in their structures did not constitute obstacles for the interaction of phosphate monoester lipids when loaded into an SPE cartridge. Our suggested approach offers a valuable tool for developing efficient analytical procedures.

Catalytic Enantioselective Access to Dihydroquinoxalinones via Formal α-Halo Acyl Halide Synthon in One Pot.

An enantioselective one-pot catalytic strategy to dihydroquinoxalinones, featuring novel 1-phenylsulfonyl-1-cyano enantioenriched epoxides as masked α-halo acyl halide synthons, followed by a domino ring-opening cyclization (DROC), is documented. A popular quinine-derived urea served as the catalyst in two out of the three steps performed in the same solvent using commercially available aldehydes, (phenylsulfonyl)acetonitrile, cumyl hydroperoxide and 1,2-phenylendiamines. Medicinally relevant 3-aryl/alkyl-substituted heterocycles are isolated in generally good to high overall yield and high enantioselectivity (up to 99 % ee). A rare example of excellent reusability of an organocatalyst at higher scale, subjected to oxidative conditions, is demonstrated. Mechanistically, labile α-ketosulfone has been detected as the intermediate involved in the DROC process. Theoretical calculations on the key epoxidation step rationalize the observed stereocontrol, highlighting the important role played by the sulfone group.

Graphitized Carbon Black Enrichment and UHPLC-MS/MS Allow to Meet the Challenge of Small Chain Peptidomics in Urine.

Short peptide sequences represent emerging analytes in a variety of fields, including biomarker discovery, but also a well-known analytical challenge in complex matrices, due to the low abundance, extensive suppression during MS analysis, and lack of workflows, as they cannot be identified by ordinary peptidomics strategies and coverage is extremely limited by metabolomics as well. In this context, in this work, a solid phase extraction method was developed for the cleanup and enrichment of dipeptides, tripeptides, and tetrapeptides in urine using graphitized carbon black Carbograph 4 as the sorbent. The method was first developed on analytical standards spiked in urine, with recoveries in the range of 60-100%. Then the method was applied to urine samples from healthy volunteers. The enriched urine samples were analyzed by ultrahigh performance liquid chromatography (UHPLC) using an orthogonal strategy in which both a reversed phase (RP) C18 column and a zwitterionic hydrophilic interaction liquid chromatography (HILIC) column were used, for better coverage of peptide polarity and improved detection of peptides. High-resolution mass spectra were acquired in data-dependent mode using a suspect screening strategy with inclusion list; peptides were identified by a semiautomated workflow for feature extraction, candidate mass filtering, and MS/MS spectra comparison with in silico mass spectra. The complementarity of the orthogonal separation strategy was confirmed by peptide identification, resulting in 101 peptides identified from the RP runs and 111 peptides from the HILIC runs, with 60 common identifications. The method is applicable to both hydrophobic and hydrophilic peptides. Peptides were stable over 2 h after collection and protease inhibitors were not necessary, as no formation of artifacts was observed.

Micro-solid-phase extraction coupled to desorption electrospray ionization-high-resolution mass spectrometry for the analysis of explosives in soil.

Home-made micro-solid-phase extraction (SPE) cartridges using different adsorbent materials were tested for the desorption electrospray ionization-high-resolution mass spectrometry (DESI-HRMS) determination of explosives like 2,4,6-trinitrotoluene, cyclotrimethylene-trinitramine, cyclotetramethylene-tetranitramine, pentaerythritol tetranitrate, and trinitrophenylmethylnitramine in soil samples. Quantitation limits in the low nanogram per kilogram range proved the reliability of the method for the detection of explosives at ultra-trace levels. The reduced sample preparation allowed for low costs and high-throughput analyses. Finally, the superior extraction capability of the method was proved by obtaining DESI-HRMS responses at least five times higher than those achieved by performing DESI-HRMS analyses of solid-liquid extracts spotted onto commercial polytetrafluoroethylene slides.

Fast determination of underivatized gentamicin C components and impurities by LC-MS using a porous graphitic carbon stationary phase.

Gentamicin C antibiotics are important because they are active against many multidrug-resistant Gram-negative bacilli. Unfortunately, their clinical usefulness is limited by their toxicity. Because of the difficulty involved in separating its different components, the US and European pharmacopeias both specify that the composition of gentamicin C should be determined by liquid chromatography with pulsed electrochemical detection. Here, we assess the usefulness of a porous graphitic carbon (PGC) HPLC column for separating the components of gentamicin C, and report chromatographic conditions that enable its direct characterization by PGC chromatography directly coupled to electrospray mass spectrometry. Native major components of gentamicin and impurities in commercial formulations were retained and separated on the PGC column without any need for derivatization, using mobile phases basified with ammonium hydroxide. When coupled with detection by conventional electrospray ion trap mass spectrometry (ESI-IT-MS), several previously reported impurities were detected easily, including the most polar gentamicin impurity, garamine. When operating in full-scan mode, it was possible to identify and quantitate gentamicin-related compounds using injected samples of only a few picograms. Under the described conditions, all analytes were eluted in less than 10 min and the LC-MS analyses exhibited excellent stability and linearity. The method's effectiveness was evaluated by analyzing commercial gentamicin batches and in-house formulations. When the PGC chromatographic system was coupled to an evaporative light-scattering detector, detection limits of 40-70 ng were achieved for various major gentamicin components. The chromatographic method was applied on a semi-preparative scale to purify the five major components.

Optimization of microwave-assisted extraction of antioxidant compounds from spring onion leaves using Box-Behnken design.

Many studies have explored the extraction of bioactive compounds from different onion solid wastes, such as bulb, skin, and peel. However, onion leaves have received limited attention despite their potential as a valuable source of nutraceutical compounds. This study aimed to valorise, for the first time, the agricultural waste in the form of spring onion leaves (CN, Cipollotto Nocerino) to obtain antioxidant-rich polyphenolic extracts. A Box-Behnken design (BBD) was used to assess the impact of microwave-assisted extraction (MAE) variables (temperature, time, extraction volume, and ethanol concentration) on total polyphenol content (TPC) measured by Folin-Ciocalteu method and the antioxidant power determined by FRAP assay. Response surface methodology (RSM) was applied, and regression equations, analysis of variance, and 3D response curves were developed. Our results highlighted that the TPC values range from 0.76 to 1.43 mg GAE g-1 dw, while the FRAP values range from 8.25 to 14.80 mmol Fe(II)E g-1 dw. The optimal extraction conditions predicted by the model were 60 °C, 22 min, ethanol concentration 51% (v/v), and solvent volume 11 mL. These conditions resulted in TPC and FRAP values of 1.35 mg GAE g-1 dw and 14.02 mmol Fe(II)E g-1 dw, respectively. Furthermore, the extract obtained under optimized conditions was characterized by UHPLC-ESI-Orbitrap-MS analysis. LC/MS-MS platform allowed us to tentatively identify various compounds belonging to the class of flavonoids, saponins, fatty acids, and lipids. Finally, the ability of CN optimal extract to inhibit the intracellular reactive oxygen species (ROS) release in a hepatocarcinoma cell line using an H2O2-induced oxidative stress model, was evaluated. The results highlighted the potential of CN extract as a valuable source of polyphenols with significant antioxidant properties, suitable for various applications in the food and pharmaceutical industries.

A High Copy Number from a Pharyngeal Swab Is Not Associated with Different Presenting Features in 100 Children with Acute Adenovirus Infection from a Cluster in Italy.

Human mastadenoviruses, frequently denominated adenoviruses (HAdVs), may cause respiratory tract, gastrointestinal or, less frequently, other involvements. Epidemics of HAdV infections occur globally, in communities, and in closed or crowded settings. In our institution, a cluster of infants and children admitted for HAdV infection was recently observed. The aim of this study was to describe the pattern of their presenting features and investigate the possible correlation between the HAdV copy number and the clinical picture. Two main patterns of clinical presentation were observed: 68 patients had mainly respiratory symptoms (pharyngitis n = 67, cough n = 44; tonsillar exudate n = 17; other respiratory signs n = 4) while 26 patients showed prevalent gastrointestinal involvement (diarrhea n = 26, vomiting n = 8). Patients with respiratory symptoms had a significantly higher count of WBC, PMN, and platelets, while CRP level approached statistical significance (p = 0.07) for higher values in the patients with diarrhea. In order to explore the impact of selected presenting features, the possible association between the level of CRP and the presence of pharyngeal exudate, cough, vomiting, diarrhea, duration of fever, number of neutrophils, and administration of antibiotics was analyzed. Patients falling in the tertile with more elevated CRP values had tonsillar exudate and diarrhea significantly more often, while those in the lower tertile had a 4.4-day duration fever vs. ≥5.0 days in the remaining patients. Antibiotic therapy was administered more frequently to patients with higher values of CRP (p = 0.006). The duration of hospitalization was not associated with the CRP level. The median time from the receipt of a positive HAdV PCR test result to patient discharge was 1 day in 73% of cases. The number of copies of HAdV detected via PCR ranged between 47 million and 15/µL. Falling in the highest tertile of copy number was significantly associated with pharyngitis. The 24 patients with evidence of viral coinfection had no difference in the demographics or presenting features, with the only exception being a significantly higher leukocyte count. The rapid turn-around of the results of the molecular testing of the HAdV genome on a pharyngeal swab allowed us to rapidly diagnose HAdV infection, allowing us to stop antibiotic therapy and immediately discharge the patients, with reduced discomfort for the families and more appropriate use of hospital beds. A high copy number of HAdV from a pharyngeal swab should not be taken as an indicator of worse prognosis, thus allowing for the preferential use of qualitative rather than quantitative assay.

Integrating ZooMS and zooarchaeology: New data from the Uluzzian levels of Uluzzo C Rock Shelter, Roccia San Sebastiano cave and Riparo del Broion.

In this study we explore the potential of combining traditional zooarchaeological determination and proteomic identification of morphologically non-diagnostic bone fragments (ZooMS) collected from the Uluzzian levels of three Italian sites: Uluzzo C Rock Shelter, Roccia San Sebastiano cave, and Riparo del Broion. Moreover, we obtained glutamine deamidation ratios for all the contexts analysed during routine ZooMS screening of faunal samples, giving information on collagen preservation. We designed a selection protocol that maximizes the efficiency of the proteomics analyses by excluding particularly compromised fragments (e.g. from taphonomic processes), and that aims to identify new human fragments by favouring bones showing morphological traits more similar to Homo. ZooMS consistently provided taxonomic information in agreement with the faunal spectra outlined by traditional zooarchaeology. Our approach allows us to delineate and appreciate differences between the analysed contexts, particularly between the northern and southern sites, related to faunal, environmental, and climate composition, although no human remains were identified. We reconstructed the faunal assemblage of the different sites, giving voice to morphologically undiagnostic bone fragments. Thus, the combination of these analyses provides a more complete picture of the faunal assemblage and of the paleoenvironment during the Middle-Upper Palaeolithic transition in Italy.

Extending the applicability of pressurized hot water extraction to compounds exhibiting limited water solubility by pH control: curcumin from the turmeric rhizome.

Pressurized hot water extraction (PHWE, also known as subcritical water extraction) is commonly considered to be an environmentally friendly extraction technique that could potentially replace traditional methods that use organic solvents. Unfortunately, the applicability of this technique is often limited by the very low water solubility of the target compounds, even at high temperatures. In this paper, the scope for broadening the applicability of PHWE by adjusting the pH of the water used in the extraction is demonstrated in the extraction of curcumin (which exhibits very limited water solubility) from untreated turmeric (Curcuma longa L.) rhizomes. Although poor extraction yields were obtained, even at high temperatures when using degassed water or neutral phosphate buffer as the extraction medium, yields exceeding those obtained by Soxhlet extraction were achieved using highly acidic pH buffers due to curcumin protonation. The influence of the temperature, pH, and buffer concentration on the extraction yield were investigated in detail by means of a series of designed experiments. Optimized conditions for the extraction of curcumin from turmeric by PHWE were estimated at 197 °C using 62 g/L buffer concentration at pH 1.6. The relationships between these variables were subjected to statistical analysis using response surface methodology.

Shotgun proteomic analytical approach for studying proteins adsorbed onto liposome surface.

The knowledge about the interaction between plasma proteins and nanocarriers employed for in vivo delivery is fundamental to understand their biodistribution. Protein adsorption onto nanoparticle surface (protein corona) is strongly affected by vector surface characteristics. In general, the primary interaction is thought to be electrostatic, thus surface charge of carrier is supposed to play a central role in protein adsorption. Because protein corona composition can be critical in modifying the interactive surface that is recognized by cells, characterizing its formation onto lipid particles may serve as a fundamental predictive model for the in vivo efficiency of a lipidic vector. In the present work, protein coronas adsorbed onto three differently charged cationic liposome formulations were compared by a shotgun proteomic approach based on nano-liquid chromatography-high-resolution mass spectrometry. About 130 proteins were identified in each corona, with only small differences between the different cationic liposome formulations. However, this study could be useful for the future controlled design of colloidal drug carriers and possibly in the controlled creation of biocompatible surfaces of other devices that come into contact with proteins into body fluids.

Screening and quantification of pesticides in water using a dual-function graphitized carbon black disk.

A simple platform for combining solid phase extraction (SPE) and surface-assisted laser desorption ionization mass spectrometry (SALDI-MS) of extracted analytes, using disks prepared by embedding graphitized carbon black (GCB-4) particles in a network of polytetrafluoroethylene (PTFE), is presented. The system provides a convenient approach for rapid SALDI-MS screening of substances in aqueous samples, which can be followed by robust quantitative and/or structural analyses by liquid chromatography (LC)/MS/MS of positive samples. The extraction discs are easily transferred between gaskets where the sample extraction and desorption of selected samples is performed and the mass spectrometer. The SPE and SALDI properties of the new GCB-4 disc have been characterized for 15 pesticides with varying chemical properties, and the screening strategy has been applied to the analysis of pesticides in agricultural drainage water. Atrazine and atrazine-desethyl-2-hydroxy were detected in the sampled water by SALDI-MS screening and subsequently confirmed and quantified using LC/MS/MS.

Sensitive untargeted identification of short hydrophilic peptides by high performance liquid chromatography on porous graphitic carbon coupled to high resolution mass spectrometry.

The combination of an efficient chromatographic separation with post-column addition of a supercharging agent was evaluated for the determination of small peptides. The procedure takes advantage of porous graphitic carbon (PGC) ability in retaining very polar and ionic molecules to overstep the poor retention of small peptides on conventional reversed phase (RP) columns. The method was developed specifically for the most hydrophilic di-, tri- and tetrapeptides, which are not identified in ordinary peptidomics experiments. In addition to retention mechanisms acting on conventional RP, the method exploited the charge induced interactions generated by the charges on the peptides with the polarizable surface of PGC. This results in efficient retention of very short and highly polar peptides using classical RP mobile phases. The effects of varying mobile phase composition (organic solvent and ion-pairing additives) as well as column temperature have been thoroughly investigated using short peptide standards. Under optimized conditions (water and acetonitrile/tetrahydrofuran 99:1 (v/v), both with 0.15% trifluoroacetic acid, as phase A and B, respectively, 0.5 mL min-1 flowrate at 50 °C) the effect of post-column addition of 3-nitrobenzylic alcohol was also investigated allowing effective coupling of the chromatographic system with high resolution mass spectrometry. Finally, an untargeted approach for peptide identification was pursued, based on precursor identification in database with all possible combinations of the 20 natural amino acids and fragmentation spectra matching to in silico generated spectra. The method was then applied to investigation of the short endogenous peptides in human serum from healthy individuals resulting in the identification of 30 short peptides.

Feasibility of analyzing fine particulate matter in air using solid-phase extraction membranes and dynamic subcritical water extraction.

We have evaluated the feasibility of using Empore solid-phase extraction (SPE) membranes as an alternative to conventional techniques for sampling fine airborne particulate matter (PM), including nanoparticles, utilizing a scanning mobility particle sizer (SMPS) and a condensation particle counter to evaluate their efficiency for trapping fine particles in the 10-800 nm size range. The results demonstrate that the membranes can efficiently trap these particles and can then be conveniently packed into an extraction cell and extracted under matrix solid-phase dispersion (MSPD) conditions. The potential utility of sampling PM using Empore membranes followed by dynamic subcritical water extraction (DSWE) for fast, efficient, class-selective extraction of polycyclic aromatic hydrocarbons (PAHs) associated with the particles, prior to changing the solvent and analysis by GC/MS, was then explored. The performance of the method was tested using National Institute of Standards and Technology (NIST)-certified "urban dust" reference material (SRM 1649a) and real samples collected at a site in central Rome with heavy road traffic. The method appears to provide comparable extraction efficiency to that of conventional techniques and with using GC/MS, detection limits ranged in the few picograms per cubic meter level. Sampling PM by Empore membranes may reduce the risks of losses of semivolatile compounds, while allowing relatively high sampling flow rates and safe sample storage. Moreover, the combination of MSPD with DSWE permits specific fractions of the PM components to be eluted, thereby generating clean extracts and reducing both analysis time and sample manipulation.

Mu-trap for the SALDI-MS screening of organic compounds prior to LC/MS analysis.

A procedure for rapidly screening and quantitatively analyzing organic molecules is presented, in which a miniaturized solid-phase extraction (SPE) cartridge containing 0.6 mg of graphitized carbon black (the GCB-mu-trap) is used for sample pretreatment. Then surface-assisted laser desorption ionization time-of-flight mass spectrometry (SALDI-TOF-MS) screening is followed by liquid chromatography/mass spectrometry (LC/MS) for robust quantitative analysis of samples containing analytes of interest. Liquid samples with volumes up to 100 mL were extracted using the GCB-mu-trap, and SALDI screening was performed by transferring a few particles of the GCB 4 sorbent from the mu-trap onto a stainless steel plate. Analytes were then simply ionized and desorbed by irradiating the GCB 4 particles without any further pretreatment. GCB 4 was found to be an excellent surface for the SALDI analysis of small molecules, providing spectra with very clean backgrounds. The small size of the cartridge (micropipet filter tip) results in enrichment of the analytes on a small surface area, affording low SALDI-TOF-MS detection limits. Furthermore, the removal of just a few particles from the mu-trap does not significantly affect the subsequent quantitative determination. This approach offers considerable reductions in analytical costs by eliminating unnecessary SPE-LC/MS analyses.

Active single-drop microextraction for the determination of gaseous diisocyanates.

This paper presents a novel application of active single-drop microextraction (SDME) for the determination of mixtures of four gaseous diisocyanates: 2,4- and 2,6-toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI) and methylene diphenyl diisocyanate (MDI). The optimised simultaneous extraction, preconcentration and derivatization method utilizes a 2.3-microL Milli-Q water drop containing dibutylamine (DBA) as a derivatization reagent and phenylisocyanate (PHI) as an injection standard. A type III screening design, combined with Box-Behnken surface modelling and Simplex optimisation was applied to optimise the method. Several SDME approaches--standard SDME, automatic organic solvent film (OSF) and use of a supported-drop (SD) device--were compared with solid-phase microextraction (SPME) in terms of sensitivity and robustness under varied conditions. Of these SDME alternatives, SD proved to be the most suitable for diisocyanate sampling. The detection limits using SDME followed by UPLC-MS-MS analysis were 0.9 and 0.8 microg m(-3) for 2,4- and 2,6-TDI, respectively, 1.0 microg m(-3) for HDI and 0.2 microg m(-3) for MDI.

Chemicals from textiles to skin: an in vitro permeation study of benzothiazole.

Despite the possible impact on human health, few studies have been conducted to assess the penetration and accumulation of contaminants in the skin after a prolonged contact with textile materials. In previous studies, we have shown that benzothiazole and its derivatives, as well as other potentially hazardous chemicals, often are present as textile contaminants in clothes available on the retail market. Since benzothiazole is a common contaminant in clothes, these can be a possible route for human chemical exposure, both systemic and onto the skin. To investigate this potential exposure, Franz-type and flow-through cells were used for the permeation studies together with a Strat-M® artificial membranes. Experiments were performed using solutions of benzothiazole, as well as contaminated textile samples in the donor chamber. Benzothiazole was demonstrated to penetrate through, as well as being accumulated in the membrane mimicking the skin. After 24 h, up to 62% of benzothiazole was found in the acceptor cell, while up to 37% was found absorbed in the skin mimicking membrane. It also was shown that there was release and permeation from contaminated fabrics. The results indicate that benzothiazole can be released from textile materials, penetrate through the skin, and further enter the human body. This will possibly also apply to other chemical contaminants in textiles, and the results of this study indicate that the presence of these textile contaminants entails potential health risks. A rough risk assessment was made for clothing textiles according to Environmental Protection Agency (EPA) and European regulations for carcinogenic and non-carcinogenic compounds, using literature data for benzothiazole.

Determination of the flame retardant tetrabromobisphenol A in air samples by liquid chromatography-mass spectrometry.

An original method based on LC-MS for determination of the flame retardant tetrabromobisphenol A (TBBPA) in air is presented, as an alternative to the traditionally used GC-MS. The soft ionization in LC-MS makes it possible to monitor the intact molecule and to use 13C-labelled TBBPA as an internal surrogate standard, two features that improve both accuracy and precision of the analyses. Comparison of different acquisition modes in electrospray ionization showed that the lowest detections limit, 3.1 pg TBBPA injected, was obtained in SIM monitoring the molecular ions 542.7/544.7. A fragmentation pathway of TBBPA in LC-ESI-MS is suggested. The only sample clean-up steps required are solvent reduction and filtration of the sample extract. Recoveries were 93% at a 30 ng level and 75% at 3 ng. The new method was tested by analyses of air samples collected at a recycling plant for electronic equipment. The amount of TBBPA found was 13.8 ng/m3 with an RSD of 5.9%. Furthermore, it was found that TBBPA in a standard solution could be partially debrominated, if not carefully protected from light during storage.

Air sampling with Empore solid phase extraction membranes and online single-channel desorption/liquid chromatography/mass spectrometry analysis: determination of volatile and semi-volatile organophosphate esters.

A method for determining organophosphate esters in air samples using C8 Empore solid phase extraction (SPE) membranes has been developed. After the sampling the analytes trapped in the membrane are completely desorbed with methanol, using an extraction cell connected online to the organic modifier channel of a HPLC gradient pump. The addition of water to the mobile phase prior to analytical chromatography ensures that the analytes are refocused and efficiently separated. Sampling with Empore SPE membranes enables the collection of analytes in both the vapour phase and particulate matter. During the air sampling procedure no losses were observed after 24 h of sampling, yielding a total volume of 14.4 m3, even for the most volatile compound used in this investigation (trimethylphosphate). Complete desorption was observed for all the organophosphate esters and recoveries were greater than 95%, with a relative standard deviation of less than 8%. The limits of detection ranged between 0.4 and 19 pg/m3. The effect of particulate matter on the extraction efficiency was investigated in detail by spiking the membranes with reference standard material. It was also found that the SPE membranes could be stored for at least 5 days at room temperature without any evidence of loss. The efficacy of the method was verified using real samples from different common indoor environments. Interestingly, significant quantities of several phosphate esters were found in a NIST standard reference material (urban dust, SRM 1649a).

Determination of aniline and quinoline compounds in textiles.

A simple method for simultaneous determination of twenty-one analytes, belonging to two classes of compounds, aromatic amines and quinolines, is presented. Several of the analytes considered in this study frequently occur in textiles goods on the open market and have been related to allergic contact dermatitis and/or are proven or suspected carcinogens. The method includes an efficient clean-up step using graphitized carbon black (GCB) that simplifies and improves the robustness of the subsequent GC-MS analysis. Briefly, after solvent extraction of the textile sample, the extract is passed through a GCB SPE cartridge that selectively retain dyes and other interfering compounds present in the matrix, producing a clean extract, suitable for GC-MS analysis, is obtained. The method was evaluated by spiking blank textiles with the selected analytes. Method quantification limits (MQL) ranged from 5 to 720ng/g depending on the analyte. The linear range of the calibration curves ranged over two order magnitude with coefficients of determination (R2) higher than 0.99. Recoveries ranged from 70 to 92% with RSDs 1.7-14%. The effectiveness of the method was tested on a variety of textile materials samples from different origin. In a pilot explorative survey, 2,6-dichloro-4-nitroaniline was detected in all the analysed clothing samples in concentrations ranging from 1.0 to 576µg/g. 2,4-dinitroaniline was detected in four of the seven samples with a highest concentration of 305µg/g. Quinoline was detected in all samples in concentrations ranging from 0.06 to 6.2µg/g.