Polycyclic Aromatic Hydrocarbons In Rainwater Research Articles

Levels and Compositions of Polycyclic Aromatic Hydrocarbons in Rainwater and Their Implication for Aquatic Environments in Urban Area in Saitama, Japan

In this study, we investigated concentrations and profiles of polycyclic aromatic hydrocarbons (PAHs) in rainwater and surface water samples collected in Saitama, an urban city located in Japan. The volume-weighted mean concentration of total PAHs in rainwater samples (dissolved + particulate) was 108.8 ng L−1 with a range of 17.6–192.9 ng L−1. Two and three benzene ring PAHs were predominantly detected, occupying 67.0% of the total concentration in rainwater samples. Individual PAH concentrations were negatively correlated with their K ow, suggesting that low-molecular-weight PAHs are preferentially scavenged owing to the higher hydrophilicity. The toxic equivalent calculated based on the relative potencies of individual PAHs showed high toxic contributions by chrysene and benz[a]anthracene in the rainwater samples. Those PAHs levels in rainwater were comparable or higher than those in adjacent river water. Correlation coefficient of PAH signatures between rainwater and surface water samples was high particularly in the dissolved phase, supporting the source/sink relationships of PAHs between wet deposition samples and receiving waters. The mean deposition flux of PAHs was 2000 ng m−2 and considered to increase with precipitation amounts.

Melamine–Formaldehyde Aerogel Doped with Boron Nitride Nanosheets as the Coating of In-Tube Solid-Phase Microextraction

To improve the performance of melamine–formaldehyde (MF) aerogel, boron nitride nanosheets (BNNs) were doped in it to get a new aerogel. The aerogel was prepared as a coating, and basalt fibers modified with it were filled in a polyetheretherketone tube for in-tube solid-phase microextraction. Its morphological structure was characterized by scanning electron microscopy. Connected with high performance liquid chromatography, it was investigated with several polycyclic aromatic hydrocarbons (PAHs) as model analytes. An online analytical method was established under the optimized conditions, including extraction volume, extraction flow rate, methanol content in sampling solution and desorption time. The method had wide linear ranges (0.016–15 µg L−1, 0.016–20 µg L−1, 0.030–20 µg L−1), satisfactory correlation coefficients (0.9968–0.9997) and low limits of detection (0.005–0.010 µg L−1). The relative standard deviations (RSDs, n = 3) of the method were in the ranges of 0.5–6.1% (intra-day) and 2.2–8.8% (inter-day). RSDs of preparation repeatability among three tubes ranged from 0.4 to 2.9%. Compared with MF aerogel coating and other materials, BNNs-doped MF aerogel showed better limits of detection, higher enrichment factors (1015–1846) and comparable extraction time, due to large specific surface area and π–π interaction with PAHs. The method was applied to detect PAHs in rainwater and a soil solution.

A Nanospherical Metal–Organic Framework UiO-66 for Solid-Phase Microextraction of Polycyclic Aromatic Hydrocarbons

Polycyclic aromatic hydrocarbons are a low content, but highly toxic organic pollutant in the environment. Because of their great threat to the health and survival of humans and other creatures, it is necessary to have a very simple and convenient as well as highly sensitive method to detect them. Based on previous studies, a nanospherical metal–organic framework UiO-66 was re-applied as the solid-phase microextraction coating and the extraction performance of polycyclic aromatic hydrocarbons was investigated. Scanning electron microscope and X-ray diffraction were used to characterize the extraction material. The extraction conditions were optimized factor by factor, and the analytical method was established with broad linear ranges (0.03–50 and 0.10–50 µg L−1), excellent correlation coefficients (0.9955–0.9993) and low limits of detection (0.01–0.03 µg L−1). The analytical method was applied to detect polycyclic aromatic hydrocarbons in rainwater and lake water, and satisfactory results were obtained. Compared with previous reports, this method had wider linear range, lower limit of detection and longer service life.

Three-dimensional multi-walled carbon nanotubes@g-C3N4@Fe3O4nanocomposites-based magnetic solid phase extraction for the determination of polycyclic aromatic hydrocarbons in water samples

In this study, three-dimensional multi-walled carbon nanotubes@g-C3N4@Fe3O4 nanocomposites (3D MWNTs@g-C3N4@Fe3O4 nanocomposites) were prepared and used as a novel magnetic solid phase extraction (MSPE) sorbent for the analysis of 16 polycyclic aromatic hydrocarbons (PAHs). The novel nanocomposites were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), and vibrating sample magnetometer (VSM) methods. To achieve the best extraction efficiency, several experimental parameters, including sorbent amount, extraction time, stirring rate, ionic strength, desorption solvent, desorption volume and desorption time, were optimized. Under the optimized preparation and extraction conditions, the proposed method showed the limits of detection (LODs) for polycyclic aromatic hydrocarbons (PAHs) were found to be in the range of 0.001–0.5 μg L−1, limits of quantification (LOQs) were in the range of 0.005–0.8 μg L−1 and their relative standard deviations (RSDs) were lower than 5.0%. The proposed MSPE method was applied successfully in the analysis of PAHs in rainwater, river water and industrial wastewater samples. The recovery of the PAHs in all samples spiked with 5 g L−1 ranged from 82.4 to 116.9% with RSDs below 9.7%.

Insitu growth of IRMOF-3 combined with ionic liquids to prepare solid-phase microextraction fibers

A superior solid-phase microextraction (SPME) fiber-coating material, IRMOF-3@ILs/PDMS, was prepared by the in situ growth of IRMOF-3 onto stainless-steel wires and protection with ionic liquids (ILs) and polydimethylsiloxane (PDMS). The ILs can efficiently prevent the substantial cracking of IRMOF-3 caused by moisture, and a thin PDMS film can protect the IRMOF-3@ILs material to achieve a much better extraction efficiency as well as excellent resistance to high temperature and high humidity. This IRMOF-3@ILs/PDMS coating possessed a porous structure, a rough surface and an increased lifespan (by at least 100 times) compared with that of IRMOF-3. The coating was evaluated by analyzing four polycyclic aromatic hydrocarbons (PAHs) in water, and good precision (<7.7%), low detection limits (12.0–15.4ngL−1), and wide linearity (50–20,000ngL−1) were achieved under the optimized conditions. The fiber was successfully applied to the sensitive analysis of PAHs in rainwater by coupling it with gas chromatography–mass spectrometry (GC–MS).

Distribution of polycyclic aromatic hydrocarbons concentrations simultaneously obtained in gas, rainwater and particles

This study reported the distribution of polycyclic aromatic hydrocarbons (PAHs) concentrations simultaneously obtained in gas/rain/particle in rain event from 2010 to 2012 in Osaka, Japan. A sampling method for rain and the materials of a rain collector were also surveyed. Benzene and a glass bottle were used to prevent the decrease of PAHs in rainwater. The average concentration of Σ9PAHs in rainwater ranged between 17.49 and 646.52 ng dm−3. The mean ratio of these Σ9PAHs in gas versus particles was 77.9 and 68.3 % during rain and no rain, respectively. During rain, the PAHs in particles were scavenged by rain and were incorporated via washout by collision with each other. Therefore, the ratio of PAHs in rainwater was similar to that in particles. The low molecular weight LMW-PAHs from gas were recognized as being dissolved in rain but did not affect the ratio of PAHs in rain. Four rings PAH were dominant in gas/rain/particles. The seasonal variation of Σ9PAHs in rainwater was reported and discussed, and the PAHs levels during the winter and spring were higher compared with that of summer and autumn. Furthermore, the sampling method of PAHs in snow is also developed.

Polycyclic Aromatic Hydrocarbons in Rainwater Collected in a Tropical Polluted Urban Area

Polycyclic aromatic hydrocarbons present in rainwater were studied in two distinct areas in Mexico City Metropolitan Area throughout the rainy season. The results showed no significant difference between the two sites, thus suggesting a more regional phenomenon driving the dissolution of the PAHs in the rain. The PAHs concentration ranged from 1.7–30.2 ngL−1with the predominance of phenanthrene, fluoranthene, and pyrene. The PAH sources were traced predominantly to vehicular emission with signature PAHs, diagnostic ratios, and cluster statistical analyses. On the other hand, the temporal analysis of the PAHs showed that the fluxes of the Total PAH were slightly different for both sites. The urban-industrial site showed fluxes that ranged from 145–3263 ng m−2d−1, while the urban site ranged from 134–3139 ng m−2d−1, with the urban site having a moderate rate at which the total PAHs diminished throughout the rainy season while the urban-industrial showed no change throughout the rainy season. This study also addressed two occurrences when studying PAHs in rain: the degradation of PAHs in the samples with acidic rain and the dilution of the PAH in the samples with continued collection of rain.

Rapid determination of polycyclic aromatic hydrocarbons in rainwater by liquid–liquid microextraction and LC with core‐shell particles column and fluorescence detection

Liquid-liquid microextraction coupled to LC with fluorescence detection for the determination of Environmental Protection Agency's 16 priority pollutant polycyclic aromatic hydrocarbons in rainwater has been developed. The optimization of the extraction method has involved several parameters, including the comparison between an ultrasonic bath and a magnetic stirrer as extractant apparatus, the choice of the extractant solvent, and the optimization of the extraction time. Liquid-liquid microextraction gave good results in terms of recoveries (from 73.6 to 102.8% in rainwater) and repeatability, with a very simple procedure and low solvent consumption. The reported chromatographic method uses a Core-Shell technology column, with particle size <3 μm instead of classical 5-μm particles column. The resulting backpressure was below 300 bar, allowing the use of a conventional HPLC system rather than the more expensive ultrahigh performance LC (UHPLC). An average decrease of 59% in run time and 75% in eluent consumption has been obtained, compared to classical HPLC methods, keeping good separation, sensitivity, and repeatability. The proposed conditions were successfully applied to the determinations of polycyclic aromatic hydrocarbons in genuine rainwater samples.

Source and deposition of polycyclic aromatic hydrocarbons to Shanghai, China

Abstract Despite recent efforts to investigate the distribution and fate of polycyclic aromatic hydrocarbons (PAHs) in air, water, and soil, very little is known about their temporal change in wet deposition. As a result of increased attention to public health, a large-scale survey on the deposition flux and distribution of PAH contamination in rainwater was urgently conducted in Shanghai, China. In this study, 163 rainwater samples were collected from six sites, and 15 PAH compounds were detected by the use of a simple solid phase microextraction (SPME) technique coupled with gas chromatography-mass spectrometry. The dominant PAH species monitored were naphthalene, phenanthrene, anthracene, and fluoranthene. The concentration of total PAHs per event was between 74 and 980 ng/L, with an average value of 481 ng/L, which is at the high end of worldwide figures. The annual deposition flux of PAHs in rainwater was estimated to be 4148 kg/yr in the Shanghai area, suggesting rainfall as a major possible pathway for removing PAHs from the atmosphere. Diagnostic analysis by the ratios of An/178 and Fl/Fl+Py suggested that combustion of grass, wood, and coal was the major contributor to PAHs in the Shanghai region. Back trajectory analysis also indicated that the pollutant sources could be from the southern part of China.

Sources and Wet Deposition Fluxes of Polycyclic Aromatic Hydrocarbons (PAHs) in an Urban Site 1000 Meters High in Central Anatolia (Turkey)

Wet-only precipitation samples were collected using an Andersen wet only sampler (Andersen Samplers, Inc., Atlanta, GA, USA), between December 2000 and June 2002, in Ankara, Turkey. Polycyclic aromatic hydrocarbons (PAHs) were first pre-concentrated using solid phase (SPE) and ultrasonic extraction procedures. They were then analyzed using gas chromatography–mass spectrometry (GC–MS). Phenanthrene (Phe), fluoranthene (Flt), benzo (b+k) fluoranthene (B (b+k) F) and pyrene (Pyr) were the major components of ∑ 14PAH concentrations during both winter and summer seasons. Concentrations of PAHs did not show a statistically significant relation with meteorological parameters, such as mixing height, wind speed, and wind direction. However, they showed a strong linear relation with the ventilation coefficient (VC), signifying the importance of local sources on measured PAH concentrations. Concentrations of PAHs in winter season were higher than their corresponding concentrations in summer season due to seasonal variations in meteorology and emissions. Sources of PAHs in rainwater were apportioned using principal component analysis. Three factors with eigenvalues > 1.0 were extracted. The two factors that explained the largest fraction of system variance represented coal and gas combustion whereas the third factor represented motor vehicles. Half of the rain events accounted for approximately 90% of the wet deposition fluxes of PAHs, demonstrating the highly episodic nature of wet PAH deposition.

Significance of Indirect Deposition on Wintertime PAH Concentrations in an Urban Northern California Creek

To investigate the main inputs and sources of polycyclic aromatic hydrocarbons (PAHs) into surface water, stream and precipitation samples were collected along an urban tributary to the Sacramento River, California. Dissolved, particulate, and colloid-bound PAHs were monitored four times between October 2004 and March 2005. The total PAH concentrations ranged from 192 to 3784 ng/L in surface water and from 77 to 236 ng/L in precipitation. Naphthalene, phenanthrene, pyrene, and benzo[g,h,i]perylene were the most abundant compounds in both rain and surface water. Surface water had truly dissolved PAH concentrations between 18 and 48 ng/L and precipitation had similar values (15-66 ng/L). PAHs larger than four rings were seldom found in the dissolved phase. Colloid-associated PAHs accounted for 4-25% of the total PAHs in rain, while they contributed only 0.1-6% to the total surface water PAHs. Indirect deposition (i.e., washoff of atmospheric particles previously deposited to land) of PAHs into surface water is likely a more significant input pathway for total PAHs than direct dry or wet deposition during the wet season in California's Mediterranean climate. During the sampling period, there was not an obvious seasonal variation in dissolved PAH concentrations of surface water despite an enormous wintertime increase in the total aqueous concentrations. Particulate matter carried by stormwater runoff was the major source of PAHs in surface water in the early rainy season; this material likely represents a combination of indirect atmospheric inputs and other non-atmospheric anthropogenic inputs (e.g., oil leaks and spills). Selected PAH ratios indicate that observed PAHs in rainwater came from pyrogenic sources and those in surface water had more complicated and variable origins.

Optimization and validation of solid phase micro-extraction (SPME) method for analysis of polycyclic aromatic hydrocarbons in rainwater and stormwater

This paper is about development of a simple and rapid solid-phase microextraction (SPME) method coupled with gas chromatography–mass spectrometry (GC–MS) for the quantitative determination of 16 polycyclic aromatic hydrocarbons (PAHs) in rainwater and stormwater samples. In this study the condition of PAHs extractions using SPME was optimized for achieving high enrichment of the analytes from aqueous samples. This condition was optimized by varying the stirring rate, salt concentration, fiber exposure time, sample pH, and sample temperature consecutively. The analysis revealed that optimal operating conditions occurred at condition of 0.5 M of sodium monochloroacetate, 65 °C, pH 7.0, agitation of 720 rpm, and an extraction time of 60 min. A desorption time of 15 min was shown to eliminate carry-over. The satisfactory linearity, detection limits and a high enrichment factor obtained prove that the method is a sensitive tool for trace level measurement. In the next step, the newly developed SPME–GC–MS method was validated for the analysis of PAHs in rainwater and stormwater samples, which resulted in high extraction recoveries from spiked synthetic rainwater and stormwater samples. This corroborates that the method is feasible for analysis of PAHs in real rainwater and stormwater analysis.

Solid-Phase Extraction and LC with Fluorescence Detection for Analysis of PAHs in Rainwater

The efficiency of extraction of polycyclic aromatic hydrocarbons (PAHs) from rainwater by solid-phase extraction (SPE) with three different types of cartridge, and analysis by high-performance liquid chromatography with fluorescence detection, are discussed in this paper. Three cartridges were investigated but only one was suitable. After equilibration in a desiccator for 65–80 h or in ambient air for 90–100 h the SPE cartridges were activated with 5 mL dichloromethane then 5 mL 2-propanol. The volume of sample passed through the cartridges was 50 mL; after loading of the sample the cartridges were dried under vacuum for approximately 20 min by application of a pressure of 15 mbar to the SPE manifold. The PAHs were eluted with 5 mL dichloromethane–hexane, 50:50 (v/v). The flow rate used for conditioning, sample loading, and elution was 2.5 mL min−1, achieved by application of a pressure of 6 mbar. For analysis of PAHs in rainwater, recovery was between 67 and 99%, the relative standard deviation varied between 2 and 5%, and the detection limits of the method were less than 16.9 ng L−1 for several PAHs. These optimum conditions were used for analysis of rainwater collected between June 2002 and May 2003 at two sites in Alsace (eastern France) and 17 PAHs were quantitatively determined. Concentrations varied between 1.6 and 968.1 ng L−1.

Polycyclic aromatic hydrocarbons in rainwater and surface waters of Lake Maggiore, a subalpine lake in Northern Italy

Fourteen polycyclic aromatic hydrocarbons (PAHs) were measured in surface waters and precipitation inputs to Lake Maggiore, a subalpine lake in Northern Italy, from July 2003 to January 2004. Particulate and dissolved phases in surface water and rain samples were determined. Analyses of PAHs were performed using XAD-2 resin to isolate the dissolved PAHs and subsequent extraction by accelerated solvent extraction (ASE). Both the dissolved and particulate phase PAH patterns in surface water and rainwater samples were dominated by the low molecular weight compounds (e.g., phenanthrene, fluoranthene and pyrene). More than 85% of PAHs in surface waters and 72% of PAHs in rainwater were associated to the dissolved phase. The ΣPAH concentrations in surface waters (particulate and dissolved phases) were 0.584 ± 0.033 ng l −1, 2.9 ± 0.312 ng l −1 and in rainwater (particulate and dissolved phases) 27.5 ± 2 ng l −1, 75.4 ± 9 ng l −1, respectively. Temporal variability of PAH concentrations in rain and surface water samples were observed, with higher concentrations in November and December, coinciding with the largest precipitation amounts. The comparison of PAH signatures in rainwater and surface waters seems to indicate that wet deposition (2.5–41 μg m −2 month −1) is the main source of PAH contamination into surface waters of Lake Maggiore.

Analysis of water contaminants and natural water samples using two-step laser mass spectrometry

The applicability of two-step laser mass spectrometry (L2MS) to the analysis of water contaminants and environmental water samples is demonstrated. First, the ionization characteristics of a selection of naphthyl and carbamate pesticides and of phenol were determined. The ion signal of all compounds increased with ionization laser pulse energy, within the investigated range (20-200 microJ). Ion yields relative to an internal standard, benz[alanthracene, reached 30% for naphthyl pesticides ionized at 225 nm and 2-8% at 266 nm. At 266 nm, similar relative ion yields were found for phenol. Carbamate pesticides showed lower relative ion yields at all wavelengths, by a factor of approximately 10-100, but higher relative ion yields, on the order of 1%, were obtained when using short (ps) laser pulses for ionization. These data allow one to estimate the detection limits of these analytes in a variety of matrixes once they are known for one of the compounds. Second, the quantitative analysis of carbaryl, phenol, and polycyclic aromatic hydrocarbons in rainwater is demonstrated. The aqueous samples were frozen to permit direct L2MS analysis of organic pollutants without tedious sample preparation. Detection limits were in the low-microgram per liter concentration range and recoveries of phenol from spiked rainwater samples were above 90%. The specific advantages are exemplified with the investigation of dynamic washout processes of atmospheric organic pollutants with a resolution of 0.01 mm of precipitation.

Determination of polycyclic aromatic hydrocarbons in precipitation using solid-phase extraction and column liquid chromatography

Solid-phase extraction (SPE) of polycyclic aromatic hydrocarbons (PAHs) on Sep-Pak C 18 cartridges was studied. Eight 3–6-ring compounds from the 16 EPA priority pollutants were selected for investigation. Factors affecting the recovery of PAHs such as conditioning of the SPE cartridge, addition of organic modifier to the sample, flow-rate of the sample loaded on the cartridge, concentration of PAHs in the sample, drying after sample loading, elution of the analytes from the SPE cartridge with different organic solvents and recovery from spiked rainwater were included. Conditioning time was shortened by omitting the application of a 2-propanol-water mixture. The presence of 25% (v/v) 2-propanol was most appropriate for the enrichment of 3–6-ring aromatic compounds on Sep-Pak C 18. The flow-rate of the sample influenced the efficiency of sample preparation of compounds with a retention volume close to the sample volume. Recoveries did not change significantly in the 20–2200 ng/l concentration range. Drying of the SPE cartridge after sample loading improved recoveries of all PAHs. Elution with dichloromethane and tetrahydrofuran gave the highest recoveries. The detection limit was found to be less than 1 ng/l for several PAHs. The concentrations of PAHs in rainwater were between 3 and 1000 ng/l.