Polycyclic Aromatic Hydrocarbons In Environmental Samples Research Articles

Preparation of porous boron nitride-doped polypyrrole-2,3,3-trimethylindole solid-phase microextraction coating for polycyclic aromatic hydrocarbon detection

Most polycyclic aromatic hydrocarbons (PAHs), which are persistent organic pollutants, have strong carcinogenicity, teratogenicity, and mutagenicity, and pose serious threats to the ecological environment and human health. Owing to the complexity of the matrix and low PAH content of environmental samples, separating and enriching PAHs in environmental samples is necessary prior to their detection. Solid-phase microextraction (SPME) technology is commonly used to detect PAHs owing to its advantages of simple operation, online connection with other instruments, low solvent usage, and integrability of sampling separation, enrichment, and desorption. The extraction coating is the core of this technology, and the type and thickness of the coating are important factors affecting the sensitivity and accuracy of the analysis. Common commercial extraction coatings include polydimethylsiloxane and quartz fiber; however, these materials have a number of disadvantages, such as poor thermal stability and high cost. Several methods, including electrochemical, sol-gel, molecular imprinting, and other coating methods, have been developed to prepare SPME coatings. Electrochemical methods have attracted considerable attention because of their simplicity, short duration, and high coating stability. In the development of an electrochemical method, the selection of the conductive polymer is of particular importance. Polypyrroles (Ppy) are easily synthesized and have numerous advantages, such as good conductivity and stable chemical properties. Thus, their use as a substrate material for SPME coatings is beneficial for improving the overall stability of the coating. Copolymerization with other polymers can enhance the adsorption performance of such coatings via synergistic effects. When doped with inorganic materials with high thermal stability, the composite coating can exhibit high temperature resistance. In this study, a porous boron nitride-doped Ppy-2,3,3-trimethylindole (Ppy/P2,3,3-TMe@In/BN) composite was prepared as a new SPME copolymer coating to detect three PAHs: naphthalene (NAP), acenaphthene (ANY), and fluorene (FLU). Scanning electron microscopy, thermal stability analysis, Fourier transform infrared spectroscopy, and other techniques were used to characterize the Ppy/P2,3,3-TMe@In/BN composite coating. The results showed that the coating featured a large number of porous and wrinkled dendritic structures, which increased the specific surface area of the composite coating and enabled the extensive enrichment of the three PAHs. When the sample inlet temperature of the chromatograph is 320 ℃, the chromatographic baseline of the coating is basically stable. Compared with commercial coatings, the prepared coating had better thermal stability. The coating formed stable intermolecular forces with the three PAHs owing to its numerous carbon-carbon double bonds (C=C), hydrogen bonds, and other structures, thereby achieving excellent enrichment of the target analytes. Compared with Ppy, Ppy/PIn, Ppy/P2,3,3-TMe@In, Ppy/BN, and polydimethylsiloxane (PDMS) coatings, the prepared Ppy/P2,3,3-TMe@In/BN composite coating exhibited better extraction effects for the three PAHs. The Ppy/P2,3,3-TMe@In/BN composite coating was polymerized on the surface of a stainless-steel wire by cyclic voltammetry and combined with gas chromatography-hydrogen flame ionization detection (GC-FID) to optimize the conditions influencing the extraction and separation of the three PAHs, thereby establishing a highly sensitive analytical method for detecting NAP, ANY, and FLU. This method had low limits of detection (LODs) of 10.6-14.5 ng/L (S/N=3) and high stability. The SPME-GC-FID method was used to detect the three PAHs in two environmental water samples, and a small amount of ANY (1.39 μg/L) was detected in one water sample. Satisfactory recoveries (82.5%-113.9%) were obtained when both water samples were spiked with the three PAHs at three levels. The experimental results indicate that the established analytical method can detect the three PAHs in environmental water samples.

Characteristics and source analysis of polycyclic aromatic hydrocarbons in organisms and manure near Ardley Island, Antarctica

In order to better understand the migration and accumulation behavior of polycyclic aromatic hydrocarbons (PAHs) in biological chains in the cold environment around the Ardley Island, a variety of biological and penguin manure samples during China's 36th Antarctic Scientific expedition have been collected and studied. A certain difference in PAHs concentration was observed in the environmental samples, and the order of size was as follows: fish > limpets > krill > manure > brown alga > mosses. The percentage of PAHs with different ring numbers in brown alga, moss, and krill was in the following order: three rings > two rings > four rings > five rings > six rings. The proportion of HMW-PAHs in limpets and fish samples was higher than that in brown alga, moss, manure, and krill samples. The main source of PAHs in environmental samples near Ardley Island is oil, which may be due to the development of tourism in Antarctica, the number of ships and human activities around the region. Therefore, it is imperative to strengthen the protection of the ecological environment in the area around Ardley Island.

Hollow bimetal-organic framework material as solid-phase microextraction fiber coating for highly sensitive detection of polycyclic aromatic hydrocarbons

Polycyclic aromatic hydrocarbons (PAHs) are among the most harmful persistent organic pollutants that possess high carcinogenicity and teratogenicity; hence, establishing a highly sensitive analytical method for monitoring PAHs in environmental samples is an urgent need. However, due to the low PAHs content in environmental samples and the complex matrix of the samples, it is difficult to directly determine the amount of PAHs using the existing analytical instruments. Therefore, an essential pretreatment of environmental samples should be carried out before instrumental analysis. In most pretreatment techniques, the extraction efficiency depends on the characteristics of the extraction materials. Currently, metal-organic framework materials (MOFs), which are porous materials self-assembled by metal ions and organic ligands, are used as solid-phase microextraction (SPME) coating materials for the extraction of PAHs. However, the following problems limit the application of MOFs in the SPME field: (1) MOF coating materials often require a long equilibration time for extraction because the it is difficult for the target to reach the deep adsorption sites; (2) In addition, most MOFs are formed by the coordination of single metal ions with organic monomers. The single type of open metal active sites is not conducive for realizing high extraction performance. In this study, a hollow bimetal-organic framework (H-BiMOF) was synthesized by the solvothermal method and characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), nitrogen adsorption-desorption analysis, thermogravimetric analysis, etc. The TEM images and XRD patterns demonstrated the successful synthesis of H-BiMOF with a hollow structure, which was formed through the competitive coordination between benzoic acid and water. The H-BiMOF material showed type-Ⅳ isotherms with a surface area of 1437 m2/g and excellent thermal stability. Subsequently, a H-BiMOF-coated SPME fiber was prepared by the physical adhesion method and used to extract trace PAHs from environmental samples. Due to the hollow structure of H-BiMOF, the prepared fibers offer the advantages of high utilization of specific surface area as well as short mass transfer distance, so that the extraction process quickly reaches equilibrium. At the same time, the introduction of bimetals provides a variety of metal active sites, which improves the extraction efficiency of the fiber against electron-rich cloud targets such as PAHs. The prepared fiber also had good service life, with at least 150 cycles. Combined with gas chromatography-tandem mass spectrometry (GC-MS/MS), a new method for the determination of PAHs in environmental water samples was established. Single factor experiments were performed to investigate the effects of the SPME conditions on the analytical performance. Under the optimal conditions, the established method showed low limits of detection (0.01-0.08 ng/L), wide linear range (0.03-500.0 ng/L), good linearity (correlation coefficients≥0.9986), and acceptable reproducibility (relative standard deviations≤9.8%, n=5). Finally, typical water samples were analyzed by the established method. Four environmental water samples were collected from Dianchi Lake, Poyang Lake, Taihu Lake, and Xihu Lake in China. No benzo(a)anthracene (BaA) and chrysene (CHR) were detected in any of the water samples. However, 17.9 ng/L of fluorene (FLU) and 5.3 ng/L of phenanthrene (PHE) were found in the Poyang Lake sample; 11.3 ng/L of fluoranthene (FLA) and 24.2 ng/L of pyrene (PYR) were found in the Taihu Lake sample; 50.0 ng/L of FLU, 19.5 ng/L of PHE, 14.9 ng/L of anthracene (ANT), 34.2 ng/L of FLA, and 44.5 ng/L of PYR were found in the Xihu Lake sample. The contents of the PAHs detected in all the lake water samples were lower than the Chinese National Standard GB 5749-2006 (2000.0 ng/L). The results of this study indicate that the developed method is suitable for the sensitive detection of trace levels of PAHs in real environmental water samples.

Development and Evaluation of Olive Flounder cyp1a1-Luciferase Assay for Effective Detection of CYP1A-Inducing Contaminants in Coastal Sediments.

Flounders have been widely used as indicator species for monitoring the benthic environment of marine coastal regions owing to their habitat and feeding preferences in or on sandy sediments. Here, a single-step, sensitive, specific, and simple luciferase assay was developed, using the olive flounder cyp1a1 gene, for effective detection of CYP1A-inducing contaminants in coastal sediments. The developed cyp1a1-luciferase assay was highly sensitive to the widely used CYP1A inducers 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo[a]pyrene (B[a]P), and 3,3',4,4',5-pentachlorobiphenyl (PCB 126). In the case of TCDD, significant dose-dependent increases in luciferase activity (0.3-300 ng/L) were detected. The assay was more sensitive to PCB 126 than to B[a]P. The assay also involved the highly sensitive expression of luciferase to extracted mixtures of PCBs and polycyclic aromatic hydrocarbons (PAHs) collected from coastal sediments. PCBs were more capable of cyp1a1 induction in the assay system at small doses than PAHs in environmental samples. Using the cyp1a1-luciferase assay along with water or sediment chemistry will certainly aid in diagnosing CYP1A-inducing contaminants in coastal environments.

Polycyclic aromatic hydrocarbon source fingerprints in the environmental samples of Anzali-South of Caspian Sea.

The major emission sources of polycyclic aromatic hydrocarbons (PAHs) in Anzali city, apportionment of these sources and transfer of PAHs through street dust and runoff to rivers and finally the Caspian Sea, were studied. PAHs in environmental samples including street dust, runoff, and river sediment samples as well as in major sources of hydrocarbons in urban area including vehicles exhaust, gasoline and diesel fuels, engine oils of automobiles and boats, asphalt, and tire debris were extracted by Soxhlet and liquid-liquid extraction in solid and liquid phase and were analyzed by GC-MS. Significance of each source in PAH emission in the area was identified by chemical fingerprinting. According to the spatial distribution of PAHs in receptor samples stations of street dust and runoff located in the center of the city with high traffic of vehicles had higher concentrations of PAHs than stations in the out bonds of the city. In the river sediment samples, the stations located in the port area had the highest concentrations of PAHs. Results of chemical fingerprinting showed that especially in street dust and runoff samples, the isometric patterns of PAHs were rather similar to those in the proposed major sources, showing that they may have been originated from them, especially from asphalt and tire. On the contrary, river sediment samples were confirmed to receive inputs from other unknown independent sources.

DETERMINATION OF POLYCYCLIC AROMATIC HYDROCARBONS IN SOIL SAMPLES USING ULTRASONIC PROBE AND SALT-ASSISTED LIQUID-LIQUID EXTRACTION COUPLED WITH HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

Background : Polycyclic aromatic hydrocarbons (PAHs) are a class of chemicals which have 2 to 7 fused aromatic rings. It is demonstrated that even trace amounts of PAHs are carcinogens, mutagens, and teratogens which can lead to serious risk to the health of humans. According to these facts, determination of PAHs in environmental samples is essential. Methods : In this study, ultrasonic in combination with salt-assisted liquid-liquid extraction was used efficiently for the extraction of PAHs from soil and water samples. In order to evaluate the performance of the proposed method three PAHs, naphthalene, anthracene and pyrene were selected as model analytes. Influential parameters on the extraction efficiency of analytes such as extraction solvent and its volume, salting-out agent and its concentration, ultrasonic time, ultrasonic amplitude and pulse were investigated and optimized. Results : The optimum conditions were as follow; extracting solvent; tetrahydofuran, extracting solvent volume; 3 mL, salting-out agent; sodium acetate, salting-out agent concentration; 20 %w/v, ultrasonic time; 10 s, ultrasonic amplitude; 60% and ultrasonic pulse; 0.5 s. The limits of quantitation for pyrene, naphthalene and anthracene were 1.0, 1.0 and 0.7 ng g-1, respectively. Under the optimum conditions, obtained recoveries in different matrices were in the range of 80.0 to 100.0% with a relative standard deviation better than 7.5%. Conclusions : In the proposed method, after the UAE, sample was exposed to SALLE without need of solid residue removal from the sample. Therefore, extraction steps such as filtration and centrifuge were removed which lead to time saving.

Metal azolate framework-66-coated fiber for headspace solid-phase microextraction of polycyclic aromatic hydrocarbons

Metal azolate frameworks (MAFs) as a subfamily of metal-organic frameworks (MOFs) have received much attention in analyzing organic volatiles owing to their remarkable structures. In this work, the headspace solid-phase microextraction (SPME) fiber based on MAF-66 has been fabricated by a layer-by-layer deposition method. To evaluate the performance of the MAF-66-coated fibers, polycyclic aromatic hydrocarbons (PAHs) were tested as analytes with gas chromatography (GC). Relevant experimental parameters were optimized including extraction temperature, extraction time, desorption temperature, desorption time, the stirring rate and salt concentration. Under optimum condition, PAHs including naphthalene, 2-methylnaphthalene, 1-methylnaphthalene, acenaphthylene, acenaphthene, fluorene and phenanthrene were detected with good linear range (0.01–100 μg L−1), low detection limits (0.1–7.5 ng L−1), high enrichment factors (123–3108) and relative standard deviations (RSDs) ranging from 0.23% to 4.2%. Additionally, the fiber exhibited a long lifetime with repetitively used more than 270 times. The proposed method was also successfully applied for the determination of PAHs in environmental samples and food samples.

Use of chicken feet yellow membrane as a biosorbent in miniaturized solid phase extraction for determination of polycyclic aromatic hydrocarbons in several real samples

In this study, chicken feet yellow membrane was treated and evaluated as a novel bio-sorbent for miniaturized solid-phase extraction of organic pollutants and determination by high performance liquid chromatography for the first time. The surface of bio-sorbent particles was characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction and Brunauer, Emmett and Teller techniques. As-prepared bio-sorbent showed excellent potential for preconcentration of polycyclic aromatic hydrocarbons (PAHs) as a model of organic pollutants. The effective experimental parameters on the extraction efficiency were optimized by one-factor-at-a-time method. Under the optimized experimental conditions, linear dynamic ranges were achieved in the range of 0.1–400.0 μg L−1 for Naphtalene, 0.005–40.0 μg L−1 for Phenanthrene, 0.001–20.0 μg L−1 for Antracene, 0.008–132.0 μg L−1 for Fluoranthene and 0.012–100.0 μg L−1 for Pyrene, with correlation coefficient ranging from 0.996 to 0.999. The limits of detection for PAHs varied between 0.37 and 38.5 ng L−1 and RSD values were obtained in the range of 2.7–5.4% (n = 8). The applicability of the method was demonstrated by analyzing the target pollutants in agricultural products, edible vegetable oils, and water samples. Due to low cost, availability, environmentally friendly, reusability and good pre-concentration factors, the developed bio-sorbent could be effectively used for the determination of PAHs in environmental samples.

A Highly Sensitive Dispersive Microextraction Method with Magnetic Carbon Nanocomposites Coupled with Dispersive Liquid–Liquid Microextraction and Two Miscible Stripping Solvents Followed by GC–MS for Quantification of 16 PAHs in Environmental Samples

In this work, a highly sensitive solid-phase-dispersive microextraction method was designed based on magnetic carbon nanocomposites as a magnetic solid-phase extraction sorbent coupled with dispersive liquid–liquid microextraction and two miscible stripping solvents (MSPE–DLLME) followed by gas chromatography–mass spectrometry (GC–MS) for determination of 16 polycyclic aromatic hydrocarbons (PAHs). By adopting this research methodology, a mixture of two miscible organic solvents is used not only as stripping solvent for MSPE, but also as extraction and disperser solvents for DLLME procedure. Several parameters such as amount of extraction adsorbent, type of stripping, extraction solvents and their volumes, salt effect, and pH and volume of sample solution were optimized to obtain high extraction recoveries. Finally, 2 µL of extraction phase was injected into GC–MS. Under optimal conditions, the method attained satisfactory precisions (RSD% ≤ 8.66), excellent limits of detection in the range of 0.1–0.5 ng kg−1 at S/N = 3, and very high enrichment factors in the range of 28,187–33,149 for 500 mL sample solution of different PAHs. The calibration curves of 16 extracted PAHs were linear in the range of 0.4–10,000 ng kg−1, with coefficients of determination (r2) between 0.9989 and 0.9999. The optimized method to determine 16 PAHs has been successfully applied in the real environment including waters, waste water, sewage, and soil.

Polyaniline-dicationic ionic liquid coated with magnetic nanoparticles composite for magnetic solid phase extraction of polycyclic aromatic hydrocarbons in environmental samples

In this present study, magnetic nanoparticles (MNPs) nanocomposites modified with polyaniline (PANI) coated newly synthesised dicationic ionic liquid (DICAT) forming MNP-PANI-DICAT were successfully synthesised as new generation material for magnetic solid phase extraction (MSPE). MNP-PANI-DICAT was characterised by FT-IR NMR, CHN, BET, SEM, TEM, and VSM techniques and the results were compared with MNP-PANI and native MNP. This new material was applied as a magnetic adsorbent for the pre-concentration and separation of polycyclic aromatic hydrocarbons (PAHs) due to the π–π interaction between polyaniline shell and dicationic ionic liquid (DICAT) with PAHs compounds. Under the optimal conditions, the proposed method was evaluated and applied for the analysis of PAHs in environmental samples using gas chromatography-mass spectrometry (GC-MS). The validation method showed good linearity (0.005–500µgL−1) with the coefficient of determination (R2) > 0.999. The limits of detection (LOD) and quantification (LOQ) of the developed method (MNP-PANI-DICAT-MSPE) were in the range of 0.0008–0.2086µgL−1 and 0.0024–0.6320µgL−1, respectively. The enrichment factor (EF) of PAHs on MNP-PANI-DICAT-MSPE were in the range of 7.546–29.632. The extraction recoveries of natural water, sludge, and soil samples were ranged from 80.2% to 111.9% with relative standard deviation (RSD) less than 5.6%. The newly synthesised MNP-PANI-DICAT possess good sensitivity, reusability, and fast extraction of PAHs under the MSPE procedure in various environmental samples.

A covalent organic framework-based magnetic sorbent for solid phase extraction of polycyclic aromatic hydrocarbons, and its hyphenation to HPLC for quantitation

A novel covalent organic framework based magnetic adsorbent was developed for magnetic solid phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs). Covalent organic framework-LZU1 (= Lan Zhou University-1) was covalently immobilized onto polyethyleneimine-functionalized magnetic nanoparticles (COF-LZU1@PEI@Fe3O4), and the resulting material was characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. The effects of the pH value of sample solution, percentage of acetonitrile, extraction time and sampling volume on MSPE of six PAHs were investigated. The COF-LZU1@PEI@Fe3O4 displays high extraction efficiency for the PAHs such as pyrene, benzo[a]pyrene, fluoranthene, benz[a]anthracene, benzo[a]fluorathene and dibenz[a,h]anthracene. Following desorption with acetonitrile, the PAHs were quantified by HPLC. The MSPE-HPLC method shows low limit of detection (0.2–20 pg mL−1), wide linear range and good reproducibility (relative standard deviations <4.4% for intra-day and inter-day precision). The method was successfully applied to determine PAHs in environmental samples. Good recoveries were obtained, ranging from 90.9 to 107.8% for water samples and 85.1 to 105.0% for soil samples.

Airborne Petcoke Dust is a Major Source of Polycyclic Aromatic Hydrocarbons in the Athabasca Oil Sands Region.

Oil sands mining has been linked to increasing atmospheric deposition of polycyclic aromatic hydrocarbons (PAHs) in the Athabasca oil sands region (AOSR), but known sources cannot explain the quantity of PAHs in environmental samples. PAHs were measured in living Sphagnum moss (24 sites, n = 68), in sectioned peat cores (4 sites, n = 161), and snow (7 sites, n = 19) from ombrotrophic bogs in the AOSR. Prospective source samples were also analyzed, including petroleum coke (petcoke, from both delayed and fluid coking), fine tailings, oil sands ore, and naturally exposed bitumen. Average PAH concentrations in near-field moss (199 ng/g, n = 11) were significantly higher (p = 0.035) than in far-field moss (118 ng/g, n = 13), and increasing temporal trends were detected in three peat cores collected closest to industrial activity. A chemical mass-balance model estimated that delayed petcoke was the major source of PAHs to living moss, and among three peat core the contribution to PAHs from delayed petcoke increased over time, accounting for 45-95% of PAHs in contemporary layers. Petcoke was also estimated to be a major source of vanadium, nickel, and molybdenum. Scanning electron microscopy with energy-dispersive X-ray spectroscopy confirmed large petcoke particles (>10 μm) in snow at near-field sites. Petcoke dust has not previously been considered in environmental impact assessments of oil sands upgrading, and improved dust control from growing stockpiles may mitigate future risks.

Polydopamine-based immobilization of zeolitic imidazolate framework-8 for in-tube solid-phase microextraction

Zeolitic imidazolate frameworks (ZIFs), a subfamily of metal-organic frameworks (MOFs), have received considerable attention as a novel porous material for sample preparation due to their fascinating structures and unique properties. Here, we developed a novel bio-inspired polydopamine (PDA) method to immobilize ZIFs inside the chemical resistance poly(ether ether ketone) (PEEK) tube for online solid-phase microextraction (SPME). Firstly, PDA layer was assembled inside the PEEK tube. Secondly, attributing to its noncovalent adsorption and covalent reaction ability, PDA could attract and anchor ZIF-8 nutrients onto the inner surface of PEEK tube to promote the nucleation and growth of ZIF-8. The morphology and surface properties of the prepared ZIF-8-PDA-PEEK tube were characterized by scanning electron microscopy and energy dispersive X-ray spectrometry. The ZIF-8-PDA-PEEK tube exhibits excellent extraction efficiency toward six polycyclic aromatic hydrocarbons (PAHs), with enrichment factor from 550 to 734. The developed online SPME–HPLC method shows good linearity (10–5000pg/mL) and low detection limits (0.5–5pg/mL) for six PAHs. It also has been used to determine PAHs in environmental samples, with recoveries in the range of 82.5–98.6%.

Etched Stainless Steel Powder as Novel Sorbent Material for Solid-Phase Extraction Coupled with High-Performance Liquid Chromatography for Determination of Polycyclic Aromatic Hydrocarbons in Water

The etched stainless steel powder was prepared and explored as sorbent material for solid-phase extraction coupled with high-performance liquid chromatography (HPLC) for determination of trace polycyclic aromatic hydrocarbons (PAHs) in environmental matrices. The etched stainless steel powder was shown to be promising for solid-phase extraction of PAHs in environmental samples with subsequent HPLC separation and UV detection. This paper explored different factors that affected the adsorption efficiency of etched stainless steel powder, including the etched time of stainless steel powder, the mass of sorbent, and the volume of water sample, and so on. In the optimum conditions, nine kinds of PAHs, including trace naphthalene, acenaphthylene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzanthracene and benzopyrene, were extracted by etched stainless powder and the extraction efficiency is satisfactory.

Separations of substituted benzenes and polycyclic aromatic hydrocarbons using normal- and reverse-phase high performance liquid chromatography with UiO-66 as the stationary phase

Metal-organic frameworks (MOFs) have great potential for applications in chromatography due to their highly tailorable porous structures and unique properties. In this work, the stable MOF UiO-66 was evaluated as both a normal-phase (NP-) and a reverse-phase (RP-) stationary phase in the high performance liquid chromatography (HPLC) to separate substituted benzenes (SBs) and polycyclic aromatic hydrocarbons (PAHs). It was found that the mobile phase composition has a significant effect on the HPLC separation. Baseline RP-HPLC separations of xylene isomers; naphthalene and anthracene; naphthalene and chrysene; and naphthalene, fluorene, and chrysene were achieved using MeOH/H2O ratios of 80:20, 75:25, 85:15, and 75:25, respectively, on the UiO-66 column. Similarly, baseline NP-HPLC separations of xylene isomers and ethylbenzene; ethylbenzene, styrene, o-xylene, and m-xylene; and several PAHs were also obtained on the UiO-66 column with different mobile phase compositions. The relative standard deviations (RSDs) of retention time, peak height, peak area, and half peak width for five replicate separations of the tested analytes were within the ranges 0.2–0.4%, 0.2–1.6%, 0.7–3.9%, 0.4–1.1%, respectively. We also evaluated other critical HPLC parameters, including injected sample mass, column temperature, and the thermodynamic characters of both the RP-HPLC and the NP-HPLC separation processes. It was confirmed that the separation of SBs on a UiO-66 column was an exothermic process, controlled by both enthalpy change (ΔH) and entropy change (ΔS). The reverse shape selectivity, size selectivity, stacking effect, and electrostatic force played vital roles in the separations of these analytes. To the best of our knowledge, this method is one of the very few examples of using MOFs as the stationary phase in both NP-HPLC and RP-HPLC. MOF-based stationary phases may thus be applied in the separations and analyses of SBs and PAHs in environmental samples.

P.4.f.001 The cumulative effect of childhood trauma on adult mental and physical health: results from the Marine Resiliency Study

In this work, we interestingly happened to observe the adsorption of stainless steel sample loop of HPLC. The adsorptive behaviors of the stainless steel loop toward different kinds of compounds were studied, including polycyclic aromatic hydrocarbons (PAHs), halogeno benzenes, aniline derivatives, benzoic acid derivatives, phenols, benzoic acid ethyl ester, benzaldehyde, 1-phenyl-ethanone and phenethyl alcohol. The adsorptive mechanism was probably related to hydrophobic interaction, electron-rich element–metal interaction and hydrogen bond. Universal adsorption of stainless steels was also testified. Inspired by its strong adsorptive capability, bare stainless steel loop was developed as a modification-free in-tube device for solid-phase microextraction (SPME), which served as both the substrate and sorbent and possessed ultra-high strength and stability. Great extraction efficiency toward PAHs was obtained by stainless steel loop without any modification, with enrichment factors of 651–834. By connecting the stainless steel loop onto a six-port valve, an online SPME–HPLC system was set up and an SPME–HPLC method has been validated for determination of PAHs. The method has exceptionally low limits of detection of 0.2–2 pg/mL, which is significantly lower than that of reported methods with different kinds of sorbents. Wide linear range (0.5–500 and 2–1000 pg/mL), good linearity (R2 ≥ 0.9987) and good reproducibility (RSD ≤ 2.9%) were also obtained. The proposed method has been applied to determine PAHs in environmental samples. Good recoveries were obtained, ranging from 88.5% to 93.8%.

Adsorptive behavior and solid-phase microextraction of bare stainless steel sample loop in high performance liquid chromatography

In this work, we interestingly happened to observe the adsorption of stainless steel sample loop of HPLC. The adsorptive behaviors of the stainless steel loop toward different kinds of compounds were studied, including polycyclic aromatic hydrocarbons (PAHs), halogeno benzenes, aniline derivatives, benzoic acid derivatives, phenols, benzoic acid ethyl ester, benzaldehyde, 1-phenyl-ethanone and phenethyl alcohol. The adsorptive mechanism was probably related to hydrophobic interaction, electron-rich element–metal interaction and hydrogen bond. Universal adsorption of stainless steels was also testified. Inspired by its strong adsorptive capability, bare stainless steel loop was developed as a modification-free in-tube device for solid-phase microextraction (SPME), which served as both the substrate and sorbent and possessed ultra-high strength and stability. Great extraction efficiency toward PAHs was obtained by stainless steel loop without any modification, with enrichment factors of 651–834. By connecting the stainless steel loop onto a six-port valve, an online SPME–HPLC system was set up and an SPME–HPLC method has been validated for determination of PAHs. The method has exceptionally low limits of detection of 0.2–2pg/mL, which is significantly lower than that of reported methods with different kinds of sorbents. Wide linear range (0.5–500 and 2–1000pg/mL), good linearity (R2≥0.9987) and good reproducibility (RSD≤2.9%) were also obtained. The proposed method has been applied to determine PAHs in environmental samples. Good recoveries were obtained, ranging from 88.5% to 93.8%.

Effect of drying conditions during sample pre-treatment on the determination of polycyclic aromatic hydrocarbons in soils

In the context of the entire analytical process, pre-treatment of soil samples is often inadequately considered although the reliability of the results is definitely compromised if the sample is not properly prepared. In this paper, the effect of drying conditions in soil sample pre-treatment on the determination of polycyclic aromatic hydrocarbons (PAHs) has been studied. A systematic approach has been adopted by varying soil type, drying temperatures and solvent polarity to highlight the effect on the analyte recovery; the relationship between PAH molecular structure and their evaporation process from soils is discussed. Experimental data demonstrate that, concerning temperature-assisted drying procedures, PAHs are divided in two distinct groups: PAHs lighter than pyrene, which are seriously affected by drying temperature; and heavier PAHs that can be considered as non-volatile compounds. For studies involving the analysis of lighter PAHs in environmental samples, working on as-received samples is necessary.

The application and demonstration of a user-friendly, antibody-based biosensor for environmental monitoring (65.33)

Abstract Monoclonal antibodies (mAbs) are a valuable resource in both clinical and environmental health. In clinical applications, mAbs have been extensively used as a diagnostic tool for the rapid evaluation of specific diseases and in targeted anti-cancer therapies, among others. Recently, mAbs have been employed in environmental monitoring applications for the detection of oil, pesticides, and many other pollutants. MAb-based biosensors have become an excellent means to achieve rapid, sensitive monitoring of a specified target. Here I describe the application of a mAb employed in a portable, user-friendly, sensor format for the detection and quantification of polycyclic aromatic hydrocarbons (PAHs) in environmental samples. PAHs are carcinogenic and found widespread in the environment. One application of this biosensor included the monitoring of estuarine water during the dredging of PAH-contaminated sediments, revealing a plume of PAHs emanating from the dredge site. The second application was the near real-time monitoring of PAHs in stormwater run-off. The ease of technology transfer was demonstrated by the operation of the biosensor by high school students in two science programs: VIMS/NASA Governor’s School Summer Internship and NSF’s GK-12 Program. Overall, these opportunities demonstrated the utility of this biosensor to rapidly and precisely quantify PAHs in environmental samples. Moreover, this biosensor technology was successfully operated by non-professionals.

Headspace single drop microextraction combined with HPLC for the determination of trace polycyclic aromatic hydrocarbons in environmental samples

A new method by combining headspace single drop microextraction (HS-SDME) with HPLC fluorescence detection for the determination of trace polycyclic aromatic hydrocarbons (PAHs) in environmental samples was developed. Aqueous solution of saturated β-cyclodextrin was used as extraction solvent and five PAHs were employed as target analytes. The factors affecting the extraction efficiency were studied in detail and the optimal extraction conditions were established. β-cyclodextrin was found to play two important roles, one is the improvement of extraction efficiency of target analytes and the other is the enhancement of their fluorescence intensities in HPLC fluorescence detection. The detection limits for the target analytes were found to be in the range of 0.004–0.247 ng/ml and the relative standard deviations (R.S.D.s) of 5.1–7.1% were obtained. The proposed method was applied to the analysis of trace PAHs in environmental samples with satisfactory results.