Styrene-divinylbenzene Polymer Research Articles

Molecular insight into algae-derived dissolved organic matters via Fourier-transform ion cyclotron resonance mass spectrometry: Effects of pretreatment methods and electrospray ionization modes

The release of algae-derived dissolved organic matter (ADOM) significantly increased in serious eutrophication waters, posing great threats to drinking water safety. Thus, the molecular composition decipherment is urgently in need. However, due to unsatisfactory pretreatment and ionization effects, the application of Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) on ADOM was limited. Therefore, the effects of pretreatment methods (cartridge type and loading) during solid-phase extraction (SPE) and electrospray ionization (ESI) modes with FT-ICR-MS on the molecular composition of ADOM were evaluated. The results showed compared with silica-based octadecyl (C18) cartridge, styrene-divinylbenzene polymer (PPL) cartridge exhibited higher recovery efficiency and retained more saturated and oxygenated compounds, such as carbohydrate-like and tannin-like. Furthermore, the recovery efficiency decreased with increasing loading, and hydrophilic and high-oxygenated carbohydrate-like and tannin-like were continuously replaced by hydrophobic and low-oxygenated aliphatic and aromatic compounds. Moreover, compared to negative ESI mode, the addition of positive ESI mode increased the molecular chemodiversity, especially more lipid-like and protein-like compounds. Thus, we proposed < 1:500 DOC/PPL mass ratio during SPE and dual ESI modes coupled with FT-ICR-MS could identify ADOM molecules more comprehensively. This work contributes to more comprehensive understanding of the molecular composition of ADOM and provides more references for pretreatment and characterization strategies of severely eutrophic waters.

Comparison of dissolved organic matter composition from various sorbents using ultra-high resolution mass spectrometry

Solid phase extraction (SPE) of a variety of diverse dissolved organic matter (DOM) endmembers through eight commercially available sorbents was examined (ENV, PLEXA, PPL, HLB, Isolute 101, C18/ENV+, C18, EnvirElut) representing styrene divinylbenzene polymer (SDVB) and silica-based sorbents. We assessed dissolved organic carbon (DOC) recovery and DOM composition via 21T Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). DOC recoveries and SPE-DOM composition differed more by endmember type than by sorbent. Silica-based sorbents retained DOM with many N-containing formulae, while SDVB-based sorbents retained DOM with more S-containing formulae. Extraction pH exerted a greater influence on DOM composition, notably through the presence of strong groupings composed of saturated and lowly oxygenated formulae at basic pH, and of aromatic and highly oxygenated formulae at pH 2, irrespective of endmember or sorbent. There was above 25% DOC recovery, regardless of sorbent or endmember; >90% of the relative abundance (RA) of molecular formulae were shared with PPL, which is currently the most commonly utilized sorbent for DOM. This clearly highlights the ability of the selected sorbents to retain representative DOM across diverse endmembers. Such findings may be useful for future targeted DOM studies (e.g., bioincubations, wastewater and drinking water applications) interested in focusing on specific compositional changes and will provide a better understanding of how organic carbon cycling is impacted by anthropogenic processes.

Influence of synthesis conditions and raw materials on the properties of N‐chlorosulfonamides immobilized on granular styrene–divinylbenzene polymer carriers

AbstractPolymer materials with immobilized functional groups–donors of active chlorine are widely used to create products with a microbiocidal effect and increased resistance to microbial contamination. In this work, various methods for the synthesis of granular styrene–divinylbenzene polymers with N‐chlorosulfonamide groups were investigated. It has been shown that the synthesis of polymers with chlorine‐active SO2NNaCl groups from a non‐functionalized styrene–divinylbenzene polymer matrix through the stage of its sulfochlorination with chlorosulfonic acid in dichloromethane for 6–7 h is optimal. These products contain approximately 11% of active chlorine and maintain a stable particle size distribution. When cation exchangers such as Purolite C100 are used as the initial polymer carrier, the content of chlorine‐active groups in the target product is approximately 9%, and an increase in the content of the dust fraction is observed. The obtained samples, regardless of the synthesis method, are capable of releasing active chlorine into solutions containing amino compounds. The microbial impurities in water also cause the emission of active chlorine in an amount that does not depend on the loading of the polymer, but is determined by the concentration of microbes, due to which a pronounced antimicrobial effect is observed. In this case, the resulting products do not cause further decomposition of the functional groups of the polymer, which indicates the high service life of the latter. The availability of raw materials, relative ease of synthesis, stability, possibility of regeneration and microbiocidal properties of the studied polymers make them promising for use as components of water and air purification systems and other products for medical and industrial purposes. © 2024 Society of Chemical Industry.

The influence of sources and solid phase extraction criteria on dissolved organic matter optical properties in aquatic systems

The integrity of studies investigating the composition of dissolved organic matter (DOM) is heavily dependent on the sampling and instrumental techniques employed. In this study, we aimed to assess the impacts of both the source of the DOM and the solid phase extraction (SPE) criteria on changes to the optical properties of DOM. Samples were collected from various aquatic environments, ranging from headwaters to the open ocean. The extraction kinetics of DOM were monitored throughout the SPE process, with alterations to the DOM verified using optical properties derived from chromophoric dissolved organic matter (CDOM), including absorbance and fluorescence measurements. The fluorescence excitation-emission matrices (EEMs) were further analyzed using PARAllel FACtor analysis (PARAFAC) to resolve the underlying chemical components. Results indicate that the reaction of DOM to acidification required for polystyrene-divinylbenzene polymer sorbent SPE varies across samples. And this variability may stem from differences in functional groups and DOM sources. The maximum carbon loading observed was 9.7 mg C per 1 g PPL, which is a widely used styrene-divinylbenzene polymer sorbent, and no overloading was noted. The dissolved organic carbon (DOC) extraction efficiency (EE) ranged from 51.5-61.5% and 27.6-40.0% for post- and extract- calculations, respectively, with no significant differences in DOC EE observed among different initial DOC concentrations, salinities, and flowrates. The differences in DOC EE across diverse sources and changes in optical proxies resulting from PPL extraction were mainly due to the heterogeneity of DOM. PPL extraction altered the overall molecular characteristics of DOM from more labile to more refractory or degraded in the open ocean and headwater source samples. Notably, high and low flowrates yielded identical SPE-DOM extraction and alterations. The results indicate that DOM sources primarily control SPE EE rather than methodological or other environmental factors. PPL SPE results in a convergence of DOM variability. These findings provide crucial insights into inter-study comparisons and the interpretability of SPE-derived DOM data from samples across diverse aquatic environments.

Solid phase extraction of ocean dissolved organic matter with PPL cartridges: efficiency and selectivity

Our current knowledge of the chemical composition of ocean dissolved organic matter (DOM) is limited, mainly because of its extreme molecular diversity, low concentration of individual compounds and the elevated ionic strength of ocean waters. As a result, many analytical methods require a previous extraction step. The efficiency and selectivity of the extraction method defines the representativeness of the extracted DOM fraction. Nowadays, the most widespread procedure for concentrating DOM is solid phase extraction (SPE) using styrene divinyl benzene polymer cartridges (PPL). Here, we investigate the effect of SPE-PPL on DOM elemental and optical properties to assess the efficiency and selectivity of this extraction method on water samples from the main intermediate and deep water masses of Arctic, Mediterranean and Antarctic origin present in the Cape Vert Frontal Zone (CVFZ, NW Africa). Furthermore, North and South Atlantic Central waters converge in this area and coastal DOM is injected by the giant upwelling filament of Cape Blanc. On one side, the colored fraction of DOM (CDOM) presented extraction efficiencies comparable to that of the bulk dissolved organic carbon (DOC), but decreased significantly with increasing wavelength, suggesting an affinity of PPL cartridges for low molecular weight organic compounds. While the protein-like fluorescent fraction of DOM (FDOM) was also extracted with the same efficiency than DOC, the extraction efficiency of the humic-like fraction was comparatively much higher. On the other side, dissolved organic nitrogen (DON) extraction efficiencies were about half that of DOC. These contrasting extraction efficiencies of the different DOM pools indicated that the extracts were enriched in N-poor, low molecular weight and recalcitrant DOM, therefore showing less variability than the corresponding bulk DOM. Furthermore, DOC, DON, CDOM and FDOM extracted were not homogeneous through the water column but displayed certain significant differences among water masses in both efficiency and selectivity.

Molecular composition and chemodiversity of dissolved organic matter in wastewater sludge via Fourier transform ion cyclotron resonance mass spectrometry: Effects of extraction methods and electrospray ionization modes

High-resolution mass spectrometry was extensively applied in molecular composition and transformation pathways of dissolved organic matter (DOM) in wastewater sludge treatments. Sample pretreatment methods and electrospray ionization (ESI) modes significant affect the accuracy of molecular characterization for DOM. This study investigated the effects of pretreatment methods (styrene divinyl benzene polymer (PPL), octadecyl (C18), and electrodialysis (ED)) on molecular characteristics of DOM in two typical wastewater sludges (waste activated sludge (WAS) and anaerobic digestion sludge (ADS)) analyzed by FT-ICR MS in both positive ESI (ESI (+)) and negative ESI (ESI (−)) modes. The results indicated that ED pretreatment exhibited the highest recovery rate of 70% ‒ 95% for sludge-derived DOM. ED and PPL performed well in recovering the different sludge-derived DOM with a high similarity of molecular characteristics (e.g., lipids, proteins/aliphatic, and lignins/CRAM-like), and the C18 method was ineffective in extracting carbohydrates, unsaturated hydrocarbons, and amino sugars. In addition, compared with single ESI (−) analysis mode, the molecular number identified by ESI (+) analysis mode was increased by 200%, especially, more unsaturated hydrocarbons and N-containing compounds were detected. Except for biogenic DOM, plenty of emerging containments (ECs) in sludge-derived DOM were identified; ESI (−) mode was more effectively in recognizing the alkyl benzene sulfonic acids (e.g., anionic surfactants); and ESI (+) mode was more effectively for plasticizers identification, for example, dioctyl terephthalate and dibutyl phthalate. This study illustrated that ED pretreatment coupled with FT-ICR MS in dual ESI modes could give more insights in complexed molecular information for DOM in wastewater sludge, and provides a theoretical basis for subsequent sludge treatments and disposals.

SYNTHESIS OF ACTIVATED CARBON FROM STYRENE DIVINYL BENZENE POLYMER RESIN

The current study focuses on the synthesis of activated carbon from styrene divinyl benzene polymer (SDVB) resins using carbonization followed by oxidation using CO&lt;sub&gt;2&lt;/sub&gt; as the activating agent. The effect of several synthesis parameters including N&lt;sub&gt;2&lt;/sub&gt; gas flow rate, temperature, rate of heating or ramp, time during the carbonization process, as well as the CO&lt;sub&gt;2&lt;/sub&gt; gas flow rate, temperature, and time during the activation process on the textural properties of the obtained carbon sample, like surface area and pore volume, has been investigated. The optimum parameters established for the carbonization process are 300 ml/min as the N&lt;sub&gt;2&lt;/sub&gt; gas flow rate, 700&amp;deg;C as the temperature, and 6&amp;deg;C/min of the ramp. Increasing gas flowrates and temperature only to certain range results in higher specific surface area (SSA) obtained during carbonization, whereas the decreased rate of heating shows a positive effect in SSA of the obtained carbon sample. The optimum parameters obtained for the activation process are 100 ml/min of N&lt;sub&gt;2&lt;/sub&gt; gas flow rate, 100 ml/min as the CO&lt;sub&gt;2&lt;/sub&gt; gas flow rate, 700&amp;deg;C as the temperature and 6&amp;deg;C/min of the ramp. The maximum surface area obtained at the optimum synthesis conditions is 881 m&lt;sup&gt;2&lt;/sup&gt;/g. It is observed that during activation, lower temperature and intermediate treatment (1 h) resulted in the maximum SSA of the activated carbon. Overall, it can be said that a protocol for obtaining the maximum surface area of activated carbon has been developed based on the in-depth study of carbonization and activation during the synthesis of activated carbon.

The bio- and thermal lability of dissolved organic matter as revealed by high-resolution mass spectrometry and thermal chemical analyses

It is critical to understand the chemical structures and lability of dissolved organic matter (DOM) in aquatic environments, as DOM represents one of the largest reduced carbon pools on earth. To achieve a comprehensive view of its composition and reactivity, DOM from both riverine and coastal waters were concurrently extracted via both ultrafiltration and modified styrene divinyl benzene polymer (PPL) based solid-phase-extraction (SPE), and further compared through multi-dimensional angles, including elemental analysis, total hydrolyzable amino acid composition, high-resolution liquid chromatography mass spectrometry (under both electrospray ionization modes), and thermochemical analysis. With a very low percentage (< 5%) of shared molecules, ultrafiltered-DOM (UDOM) and SPE-extracted DOM (SPEDOM) showed distinct differences in their bio- and thermal labilities. SPEDOM not only contained more “degraded” biomarkers, such as glycine, β-alanine, and γ-aminobutyric acid, but was also dominated by a higher abundance of more bio-recalcitrant lignin-like structures. Furthermore, thermogravimetric analysis revealed a higher activation energy of SPEDOM (138.8 ± 0.5 kJ·mol−1) than that of UDOM (125.4 ± 2.8 kJ·mol−1), suggesting that SPEDOM is more thermally recalcitrant than UDOM. Consistently, thermal slicing ramped pyrolysis showed a lower percentage of recalcitrant pyrolyzates (e.g., aromatic and phenol structures), but a higher contribution of labile compound classes (e.g., aliphatic structures) in UDOM, as well as a higher diversity of pyrolyzates from UDOM than SPEDOM. Taken together, our results demonstrated a highly heterogeneous nature in DOM composition and distinctly different bio- and thermal labilities between UDOM and SPEDOM, indicating that characterization of different fractions of DOM is needed for a comprehensive evaluation of natural DOM.

Modeling the performance of a metal-organic framework (MIL-101) for the adsorption of toluene in an industrial fluidized bed adsorber and comparison to other adsorbent materials

In the present study, the application of a metal–organic framework (MOF) is investigated for the adsorption of toluene in an industrial fluidized bed adsorber. A previously-validated steady-state model is used that takes into account interactions between bubble and emulsion phases. The change in overall removal efficiency and partial pressure profile along the bed is discussed for different design and operating parameters. The performance of MOF (MIL-101) is then compared to that of a beaded activated carbon (BAC), a porous styrene–divinylbenzene polymer (Dowex Optipore V503), and a zeolite (50:50 USY-ZSM-5). The results show an increasing trend for the removal efficiency with an increase in adsorbent feed rate, weir height, or the number of adsorber stages. Increasing gas flowrate or inlet toluene partial pressure decreases the removal efficiency. Examination of the corresponding partial pressure profiles reveals that the major contribution to toluene removal inside the bed shifts from the bottom stages (where the gas enters the bed) to the top stages (where the gas leaves the bed) with increased gas flowrate or inlet partial pressure, or with decreasing the adsorbent feed rate. Comparison of the removal efficiencies obtained with different adsorbent materials shows a general trend as MOF > BAC > polymer > zeolite, except when the adsorbent feed rate is very low or the inlet partial pressure is very high. In those cases, high apparent densities for BAC and zeolite (at constant adsorbent feed rate) create longer adsorbent retention times inside the bed and change the removal efficiency trend to BAC > MOF > zeolite > polymer. Improving the adsorbent retention time by increasing the weir height or the number of stages is suggested to remedy the removal efficiency for adsorbents with low apparent densities (e.g. MOF and polymer).

Solid-Phase Extraction of Aquatic Organic Matter: Loading-Dependent Chemical Fractionation and Self-Assembly.

Dissolved organic matter (DOM) is an important component in marine and freshwater environments and plays a fundamental role in global biogeochemical cycles. In the past, optical and molecular-level analytical techniques evolved and improved our mechanistic understanding about DOM fluxes. For most molecular chemical techniques, sample desalting and enrichment is a prerequisite. Solid-phase extraction has been widely applied for concentrating and desalting DOM. The major aim of this study was to constrain the influence of sorbent loading on the composition of DOM extracts. Here, we show that increased loading resulted in reduced extraction efficiencies of dissolved organic carbon (DOC), fluorescence and absorbance, and polar organic substances. Loading-dependent optical and chemical fractionation induced by the altered adsorption characteristics of the sorbent surface (styrene divinylbenzene polymer) and increased multilayer adsorption (DOM self-assembly) can fundamentally affect biogeochemical interpretations, such as the source of organic matter. Online fluorescence monitoring of the permeate flow allowed to empirically model the extraction process and to assess the degree of variability introduced by changing the sorbent loading in the extraction procedure. Our study emphasizes that it is crucial for sample comparison to keep the relative DOC loading (DOCload [wt %]) on the sorbent always similar to avoid chemical fractionation.

Molecular Comparison of Solid-Phase Extraction and Liquid/Liquid Extraction of Water-Soluble Petroleum Compounds Produced through Photodegradation and Biodegradation by FT-ICR Mass Spectrometry.

We apply two widely used extraction techniques, liquid/liquid extraction and solid-phase extraction with styrene-divinylbenzene polymer with a proprietary nonpolar surface priority pollutant (PPL) to water-soluble compounds generated through photodegradation and biodegradation of petroleum. We compare the molecular composition of bio- and photodegraded water-soluble organic (WSO) acids by 21 T negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). We highlight the compositional differences between the two extraction techniques for abiotic and biotic degradation processes and identify known toxic species (naphthenic acids) produced through hydrocarbon biodegradation identified by liquid/liquid extraction (LLE) that are not detected with solid-phase extraction (SPE) of the same sample. Photodegraded WSO compounds extracted by SPE-PPL correspond to species with higher O/C ratio and carbon number compared to LLE extracted compounds. Naphthenic acids, a recalcitrant class of nonaromatic carboxylic acids and known acute toxicants formed through biodegradation of oil, are detected in LLE extracts (up to C30 and double-bond equivalents, DBE < 3) but are not detected in SPE-PPL extracts. This suggests that LLE and SPE-PPL retain different water-soluble oil species based on the dominant type of oil weathering process.

Extraction of Volatile Anticancer Drugs in Air Using a Solid-Phase Extraction Type Device Followed by Gas Chromatography-Mass Spectrometric Analysis.

Ifosfamide (IF), cyclophosphamide (CP), and bendamustine (BD) are widely used anticancer drugs. These drugs have slight volatility; therefore, medical-staff exposure is of concern in the medical field. However, an accurate and quantitative detection method of these volatile drugs in air has not been reported. In this study, we developed the quantitative extraction and detection method of these volatile anticancer drugs in air. For the extraction of analytes, a solid-phase extraction-type collection device packed with styrene-divinylbenzene polymer particles was used. The extracted analytes were quantitatively eluted with 5 mL of ethanol, and the solution was concentrated to 100 μL with nitrogen purging. The analytes were analyzed using gas chromatography-mass spectrometry (GC-MS). The limit of detection of the proposed method for IF and CP was 0.017 and 0.033 ng L-1, respectively in air at an air sampling volume of 300 L. IF and CP showed slight volatility, whereas BD was not detected in GC-MS due to its lower volatility. The spiked recoveries of IF and CP in the proposed method were within the range of 95.5 to 101%. Finally, the proposed method was applied to determine the exposure of IF and CP during the dispensing of CP within a hospital dispensary room. The investigated volatile anticancer drugs were not detected in real air samples, indicating that the protection measures employed are sufficient.

Simultaneous Extraction and Determination of Volatile Organic Compounds and Semi-volatile Organic Compounds in Indoor Air Using Multi-bed Solid Phase Extraction Device.

A method for the simultaneous extraction and determination of indoor volatile compounds, including volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), was developed using a multi-bed solid phase extraction (SPE)-type collection device. The collection device was prepared by packing styrene-divinylbenzene polymer particles and activated carbon particles. The collected analytes were completely desorbed by passing 7 mL of acetone, and the solvent was then injected into a gas chromatograph-mass spectrometry without the concentration process. Because the proposed method does not require ultrasonication and a concentration process of eluted solvent, quantitative determination of a relatively volatile compound could be achieved. The total recovery including extraction and elution recoveries for all the investigated analytes were in the range from 91.6 to 109%. The limit of quantification was less than 4.0 ng L-1 for all the investigated analytes, and relative standard deviations of the peak area of the analytes in indoor air were less than 12%. The collection device could be reused for over 50 samplings.

Isotopic and optical heterogeneity of solid phase extracted marine dissolved organic carbon

Marine dissolved organic carbon (DOC) is the ocean's largest exchangeable reservoir of organic carbon. The biogeochemical cycling of DOC plays an important role in ocean carbon storage on various timescales. Solid-phase extraction (SPE) is a process used to isolate DOC from seawater for biogeochemical analysis. This study examines how DOC isotopic (Δ14C, δ13C) and optical (absorbance) properties of SPE-DOM change as a function of eluent volume (and hydrophobicity). These properties were measured in 28 SPE-DOC fractions incrementally eluted from Bond Elut PPL (styrene-divinylbenzene polymer) cartridges, totaling 32 mL of methanol. We show that the early eluted SPE-DOC has distinctly different ∆14C and δ13C values than those eluted later. This study reveals isotopic heterogeneity as a function of SPE-DOC elution volume. These results show a partitioning of two distinct sources of SPE-DOC during elution, indicating a gradual transition from “marine-like” DOC to “terrestrial-like” DOC along a hydrophobicity continuum.

Determination of phenolic antioxidants additives in industrial wastewater from polypropylene production using solid phase extraction with high-performance liquid chromatography

This paper describes a new method for the effective extraction of the residues of five synthetic phenolic antioxidants (AOs): Ditertbutylphenol (DTF), Irganox 1010, Irganox 1076, Ethanox 330 and Cyanox 1790, from industrial water produced during the polypropylene (PP) deodorization process. In the deordorization process, PP is stored in a column for an average time of four hours and exposed to nitrogen and water vapor to remove inflammable compounds which may generate atypical odors in the PP. The samples of interest were taken in the desorber, followed by cleansing and pre-concentration using modified styrene divinylbenzene polymer cartridges. Liquid chromatography was performed with a reversed phase column and diode array. The method was validated for linearity, recovery, precision, specificity, limits of detection (LOD) and limits of quantification (LOQ). The chromatographic method showed LOQ from 5.4 to 16 mg L−1 and LOD between 1.6 and 4.8 mg L−1. The worldwide challenge to develop an analytical methodology which incorporates SPE with HPLC to identify and quantify AOs in industrial wastewater is addressed in this study. The recovery percentages were above 90% for most AOs, except for Irganox 1076 which showed a value of 83.2%. The ability to separate these five AOs of most frequent use worldwide, permits precision of measurement of the degree of contamination, making it useful for environmental regulation and the protection of public health.

Extraction Mechanism of Lanthanide Ions into Silica-based Microparticles Studied by Single Microparticle Manipulation and Microspectroscopy.

Single porous silica microparticles coated with a styrene-divinylbenzene polymer (SDB) impregnated with octyl(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) were injected into an aqueous 3 mol/L nitric acid solution containing trivalent lanthanide (Ln(III)), as a high-level liquid waste model. We used the microcapillary manipulation-injection technique; and the extraction rate of Ln(III), as an Ln(III)-CMPO complex, into the single microparticles was measured by luminescence microspectroscopy. The extraction rate significantly depended on the Ln(III), CMPO, or NO3- concentration, and was analyzed in terms of diffusion in the pores of the microparticles and the complex formation of Ln(III). The results indicated that the rate-determining step in Ln(III) extraction was diffusion in the pore solution of the microparticles.

Determination of Airborne Polycyclic Aromatic Hydrocarbons by HPLC Using SPE-Type Collection Device

A solid-phase extraction-type collection device packed with Sunpak-H, styrene-divinylbenzene polymer particles, was used to identify 16 airborne polycyclic aromatic hydrocarbons (PAHs) using high-performance liquid chromatography (HPLC)-fluorescence detection and ultraviolet detector. The analytes were successfully collected with the collection device and quantitatively eluted using acetone as an elution solvent. The eluted PAHs were then separated by conventional HPLC and detected with a fluorescence or ultraviolet detector. The limit of detection of airborne PAHs was below 0.7 ng/m3 with an air sampling volume of 14,400 L. The relative standard deviations of the peak area were below 12%, and the method showed better repeatability than gas chromatographic analysis. The suitability of the method was confirmed by its application in identifying PAHs in tunnel and atmospheric air.

Quantitative Determination of Phthalate Esters from Air Samples Using a Solid-Phase Extraction-type Collection Device.

In this study, a solid-phase extraction-type collection device, with styrene-divinylbenzene polymer particles (Sunpak-H) as the adsorbent, was used for the quantitative determination of phthalate esters in air samples. The collection and elution recoveries of eight volatile phthalate esters, i.e., dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisobutyl phthalate, dibutyl phthalate, butyl-benzyl phthalate, di(2-ethylhexyl) phthalate, and dioctyl phthalate, were quantitatively evaluated. All analytes were collected using the device up to a sampling volume of 10000 L at a sampling temperature of 35°C without breakthrough. During air collection, moisture was not trapped on the adsorbent. The collected analytes were completely eluted from the device by passing 3 mL of acetone. The eluted solvent was injected into a gas chromatography-mass spectrometry system after the eluted solvent was concentrated, if necessary. After washing the adsorbent using acetone, the device could be reused more than 50 times. The limit of quantification for the analytes was less than 1 ng L-1 in air at a sampling volume of 600 L with solvent concentration. This device was successfully applied for the quantitative determination of phthalate esters in real air samples, including indoor and in-car air.

Development of a comprehensive screening method for more than 300 organic chemicals in water samples using a combination of solid-phase extraction and liquid chromatography-time-of-flight-mass spectrometry.

A comprehensive screening method for 311 organic compounds with a wide range of physicochemical properties (log Pow -2.2-8.53) in water samples was developed by combining solid-phase extraction with liquid chromatography-high-resolution time-of-flight mass spectrometry. Method optimization using 128 pesticides revealed that tandem extraction with styrene-divinylbenzene polymer and activated carbon solid-phase extraction cartridges at pH 7.0 was optimal. The developed screening method was able to extract 190 model compounds with average recovery of 80.8% and average relative standard deviations (RSD) of 13.5% from spiked reagent water at 0.20μgL-1, and 87.1% recovery and 10.8% RSD at 0.05μgL-1. Spike-recovery testing (0.20μgL-1) using real sewage treatment plant effluents resulted in an average recovery and average RSD of 190 model compounds of 77.4 and 13.1%, respectively. The method was applied to the influent and effluent of five sewage treatment plants in Kitakyushu, Japan, with 29 out of 311 analytes being observed at least once. The results showed that this method can screen for a large number of chemicals with a wide range of physicochemical properties quickly and at low operational cost, something that is difficult to achieve using conventional analytical methods. This method will find utility in target screening of hazardous chemicals with a high risk in environmental waters, and for confirming the safety of water after environmental incidents.

Development and validation of a fully automated online-SPE–ESI–LC–MS/MS multi-residue method for the determination of different classes of pesticides in drinking, ground and surface water

ABSTRACTThe present work describes a fully automated method based on online solid phase extraction–liquid chromatography–tandem mass spectrometry for the determination of different classes of pesticides, including acidic and polar pesticides and six thiamethoxam metabolites. Sample preconcentration was performed by extracting 4 mL of the sample with a single styrene-divinylbenzene polymer. Elution of the compounds was done within the high performance liquid chromatography gradient and tandem mass spectrometry determination was performed in the selected reaction monitoring mode, by recording 1–3 transitions per compound. The overall pretreatment and analysis time per sample was less than 15 min. Method validation was performed in drinking, ground and surface water. For nearly all compounds a recovery between 70% and 120% could be achieved. The limit of detection ranges from 1.2 to 18 ng/L in drinking water and 3.0 to 23 ng/L in ground and surface water. The correlation coefficients for a calibration range of 0.05–2 µg/L are between 0.9915 and 0.9999. The limit of quantification (LOQ) for all compounds lies below the required limit of 0.1 µg/L, to fulfil the Council Directive 98/83/EC. Most of the compounds easily reach an LOQ below 0.05 µg/L.