Polycyclic Aromatic Hydrocarbons In Water Samples Research Articles

Flexible and designable metal–organic framework-based electrospun nanofibrous for highly sensitive recognition of polycyclic aromatic hydrocarbons in water samples

In this study, a novel functionalized electrospun nanofibrous material was developed through a straightforward and robust approach that combines polydopamine (PDA) mediation and hydrothermal growth. This material was utilized as a SPME probe for polycyclic aromatic hydrocarbons (PAHs) analysis. Under optimal extraction conditions, the proposed method exhibited higher enrichment factors (1362–4563) and lower detection limits (0.003–0.35 ng mL−1), with relative standard deviations (RSDs) below 6.7 %. Applied to water samples, the stability and reproducibility of the nanofibrous have been validated with the intra- and inter-assay RSD in 2.3–9.8 % and 1.5–9.9 %, respectively. Acceptable recoveries of 87.1–109.2 % were achieved. Furthermore, the developed SPME-GC method was successfully applied to the analysis of PAHs in water samples.

Length-controlled hydrophobic CF3-COF as a highly efficient absorbent coating for dual-mode solid-phase microextraction of sixteen polycyclic aromatic hydrocarbons in water samples

Polycyclic aromatic hydrocarbons (PAHs), a group of seriously hazardous environmental contaminants, have attracted extensive attention due to their carcinogenicity, genotoxicity, mutagenicity, and ubiquity. In this work, the excellent hydrophobic trifluoromethyl-enriched covalent organic framework (CF3-COF) was designed and synthesized as coating of solid-phase microextraction (SPME). The CF3-COF offered a high adsorption selectivity for PAHs, which could be attributed to the multiple interactions between the CF3-COF and PAHs, including hydrophobicity interaction, π-π and H bond interactions. Furthermore, headspace (HS) and direct immersion (DI) dual-mode solid-phase microextraction (HS/DI-SPME) were innovatively integrated as a dual-mode extraction by varying the length of SPME coating on stainless-steel, which could simultaneously and efficiently extract 16 PAHs with different volatile. Amazingly, the proposed strategy achieved fast adsorption for PAHs and shortened the adsorption equilibrium time to 15 min. By further integrating with gas chromatography tandem mass spectrometry (GC–MS/MS), PAHs could be detected in the range of 0.008–0.16 ng mL−1 with a quantitative limit of 0.029–0.47 ng mL−1, respectively. The recoveries of PAHs in water samples ranged from 80.84 to 117.67 %. This work indicates that the dual-mode CF3-COF-SPME is a promising candidate for the enrichment of multiple hazardous substances in complicated samples.

In-situ preparation of β-cyclodextrin-crosslinked polymer coated glass fiber for in-tube solid-phase microextraction of polycyclic aromatic hydrocarbons from water samples

Governments and organizations are paying increasing attention to the monitoring of polycyclic aromatic hydrocarbons (PAHs) in the environment. In this study, a β-cyclodextrin-based hyper-crosslinked polymer (β-CD-HCP) was prepared via the Friedel–Crafts reaction and used as a coating for an in-tube solid-phase microextraction (IT-SPME) glass fiber based on an in-situ preparation method. Subsequently, it was used for the analysis of six PAHs in water samples. The β-CD-HCP showed an excellent adsorption performance for the PAHs owing to its unique structural characteristics and multiple bonding forces (hydrophobic interaction, π–π, and electrostatic interactions) between the β-CD-HCP and PAHs. The adsorption mechanism of the β-CD to PAHs was investigated using density functional theory calculation experiments. By coupling high-performance liquid chromatography with a diode array detector, an online analysis method was established for the PAHs with a wide linear range (0.01–20 µg L–1), high enrichment factor (2130–2670), and low limits of detection (0.004–0.008 µg L–1). The PAHs in the water samples were successfully analyzed using this proposed online method with satisfactory recoveries in the range of 79.9–106.7% and relative standard deviations under 4.0%. The above results demonstrate that the prepared β-CD-HCP-based IT-SPME glass fiber has good application prospects for the pretreatment of PAHs in various aqueous environmental samples.

Preparation of Novel Solid Phase Extraction Sorbents for Polycyclic Aromatic Hydrocarbons (PAHs) in Aqueous Media.

In this study, functionalized mesoporous silica was prepared and characterized as a stationary phase using various analytical and solid-state techniques, including a Fourier-transform infrared (FTIR) spectrometer, thermogravimetric analysis, and nitrogen sorption. The results confirmed the successful synthesis of the hybrid stationary phase. The potential of the prepared hybrid mesoporous silica as a solid-phase extraction (SPE) stationary phase for separating and enriching polycyclic aromatic hydrocarbons (PAHs) in both spiked water samples and real water samples was evaluated. The analysis involved extracting the PAHs from the water samples using solid-phase extraction and analyzing the extracts using a two-dimensional gas chromatograph coupled to a time-of-flight mass spectrometer (GC × GC-TOFMS). The synthesized sorbent exhibited outstanding performance in extracting PAHs from both spiked water samples and real water samples. In the spiked water samples, the recoveries of the PAHs ranged from 79.87% to 95.67%, with relative standard deviations (RSDs) ranging from 1.85% to 8.83%. The limits of detection (LOD) for the PAHs were in the range of 0.03 µg/L to 0.04 µg/L, while the limits of quantification (LOQ) ranged from 0.05 µg/L to 3.14 µg/L. Furthermore, all the calibration curves showed linearity, with correlation coefficients (r) above 0.98. Additionally, the results from real water samples indicated that the levels of individual PAH detected ranged from 0.57 to 12.31 µg/L with a total of 44.67 µg/L. These findings demonstrate the effectiveness of the hybrid mesoporous silica as a promising stationary phase for solid-phase extraction and sensitive detection of PAHs in water samples.

Pollution and Risk Assessment of Polycyclic Aromatic Hydrocarbons in Urban Rivers in a Northeastern Chinese City: Implications for Continuous Rainfall Events

Most studies have concentrated on the distribution of polycyclic aromatic hydrocarbons (PAHs) in air, water, and soil; however, little is known about their behavior during urban wet deposition. During frequent urban rainstorms, surface runoff carries large amounts of organic pollutants into water, which has a significant impact on the quality of the water environment. “Poseidon” made landfall in Jilin Province on 27 August, 3 September, and 7 September 2020, respectively, causing some impact on the surface water. Gas chromatography–mass spectrometry (GC–MS) was used to measure the concentrations of 16 major PAHs in stormwater and water samples from the Yitong River. The PAH concentrations in rainwater runoff gradually decreased with increasing rainfall duration. The PAHs in the Yitong River water samples were mainly composed of two to three rings, with total concentrations ranging 279.19–756.37 ng/L. Ratio characterization and principal component analysis of the sources of PAHs in the water samples revealed that some water bodies had also been contaminated by oil spills in addition to combustion emissions from coal and motor vehicle oil. Health and environmental risks were assessed for PAHs in water bodies from the Yitong River, and health risk assessment showed that exposure to PAHs in the water is not a health risk for human beings; however, the risk for children is higher than that for adults and requires attention. Although the environmental risk is moderate, the risk from Benzo(a)anthracene(BaA) alone is high and requires ongoing attention. In terms of the sustainability of drinking water sources, consideration should be given to taking necessary regulatory and protective measures to prevent further contamination. These results serve as a guide for managing PAHs in urban water bodies and managing water pollution.

Occurrence and probabilistic risk assessment of PAHs in water and sediment samples of the Diep River, South Africa

This study investigated the levels of polycyclic aromatic hydrocarbons (PAHs) in water and sediment samples of the Diep River freshwater system of Western Cape Province, South Africa. A solid-phase extraction - gas chromatography - flame ionisation detection (SPE-GC-FID) method was utilised to simultaneously determine the 16 United States Environmental Protection Agency (US EPA) listed priority PAHs in water and sediment samples. The seasonal averages of individual PAH detected at the studied sites, ranged between not detected (Nd) and 72.38 ± 9.58 μg/L in water samples and between Nd and 16.65 ± 2.63 μg/g in the corresponding sediment samples. The levels of PAHs measured in water and sediment samples were subjected to probabilistic risk assessment to predict the possibility of regulatory values being exceeded. The average percentage exceedence of 63.26 was obtained for PAHs in water samples of the Diep River, while the corresponding average percentage exceedence obtained for sediment sample was 63.71. Sufficient exposure of humans and aquatic organisms to the exceedance levels obtained, would cause adverse health effect.

Polycyclic aromatic hydrocarbons in fishes and some environmental samples on the coast of Ghana

Abstract. Osei-Yeboah E, Appiah-Opong R, Ofosuhene M. 2020. Polycyclic aromatic hydrocarbons in fishes and some environmental samples on the coast of Ghana. Ocean Life 4: 4-16. The shift in industrialization in our society, including mining of coal and minerals, drilling for oil has led to the accumulation of xenobiotic products and natural chemical substances. The activities from mining and drilling have continuously contributed to the release of polycyclic aromatic hydrocarbons (PAHs) and lead to their deposition in coastal environments. The process ultimately leads to bioaccumulation in plants and animals, creating dangerous pollutants. PAHs is a well-known cause of cancer, mutation, and embryonic pathologies. In Jubilee oil fields, Ghana, oil drilling is ongoing. However, onshore baseline environmental assessment of PAHs has not yet been performed. In this study, we performed an environmental assessment of some communities bordering the oil drilling fields to establish (i) levels of fish DNA adduct formation of fishes, (ii) levels of PHA in soil, plants, water, and fish. Several fishes from three study areas showed the presence of micronuclei as evidence in the examination of blood smears, although their mean micronucleated frequencies were below the threshold frequency of 15%. There was no statistical difference between their mean frequencies using one-way ANOVA analysis with a p-value < 0.05 except that of the data from one species, Chloroscombrus chrysurus (Linnaeus, 1766). Reverse-phase HPLC analysis of fish, water, plant and soil samples collected from six study sites was performed. Two fish species Pomadasys incisus (Bowdich, 1825) at Aboadze and Thunnus alalunga (Bonnaterre, 1788) from Dixcove recorded four and one PAH compound, respectively with concentrations above the maximum contaminant levels of 30 ?g/kg set by the USEPA. The mean concentration of PAHs in water samples from two of the four study areas ranged from 1.4 to 1255 ?g/L. All samples recorded concentrations above the threshold limit value of 50 ng/L set by the World Health Organization. Sixty plant samples were collected across the six study areas, and only Erythrina senegalensis DC. and Ficus umbellata Vahl recorded the presence of PAHs with concentrations in the range of 0.15-4.70 mg/kg. Soil samples were collected from two different depths of 0-15 cm and 15-30 cm. The mean concentration of PAHs in surface soils (0-15cm) ranged from 0.1 to 95 mg/Kg, with that at 15-30 cm ranging from 0.12 to 105 mg/kg. The PAH composition profile in all the samples was similar, with 2- 3 ring PAHs being dominant, which is suggestive of a petrogenic source.

Determination of Volatile Water Pollutants Using Cross-Linked Polymeric Ionic Liquid as Solid Phase Micro-Extraction Coatings.

Ionic liquids found a wide application in catalysis and extraction due to their unique properties. Herein, ethylene glycol dimethacrylate as the cross-linker and 1-vinyl-3- butylimidazolium tetrafluoroborate as functional monomer via thermally initiated free-radical polymerization was prepared as a novel copolymer solid phase micro-extraction (SPME) coating. A surface modified stainless-steel wire was implemented as the substrate. Factors affecting the extraction performances of the copolymer, including the molar ratio of monomers to cross-linkers, the amount of porogen agent, and polymerization time were evaluated and optimized. To evaluate the extraction performance, five commonly seen polycyclic aromatic hydrocarbons (PAHs) were taken as the analytical targets. The potential factors affecting extraction efficiency were optimized. The as-prepared SPME device, coupled with gas chromatography, was successfully applied for the determination of PAHs in water samples. The wide linear range, low detection limit, good reproducibility, selectivity, and excellent thermal stability indicate the promising application of the newly developed SPME fiber in environmental monitoring as well as in other samples having complex matrices.

Occurrence of PAHs in water samples of the Diep River, South Africa

Occurrence of polycyclic aromatic hydrocarbons (PAHs) in freshwater may aggravate the water crisis currently being experienced in the Western Cape Province of South Africa. However, there is dearth of data on the levels of PAHs, which is necessary for effective assessment of water quality as well as remediation strategies. This study therefore assessed levels of PAHs in the Diep River freshwater system of Western Cape Province, South Africa. A liquid-liquid extraction solid-phase extraction gas chromatography flame ionisation detection (LLE-SPE-GC-FID) method was developed to simultaneously determine the 16 United States Environmental Protection Agency (USEPA) listed priority PAHs in water samples. The SPE-GC-FID method allowed an acceptable linearity (R2 > 0.999) within the calibration range of 1 to 50 µg/mL. Instrument detection limits ranged between 0.02 and 0.04 µg/mL and instrument quantification limits between 0.06 and 0.13 µg/mL. Recovery study results were also acceptable (83.69–96.44%) except for naphthalene, which had recovery of 60.05% in spiked water matrix. The seasonal averages of individual PAH detected at the studied sites ranged between not detected (nd) and 72.38 ± 9.58 µg/L in water samples.

Future Trends for In Situ Monitoring of Polycyclic Aromatic Hydrocarbons in Water Sources: The Role of Immunosensing Techniques.

Polycyclic aromatic hydrocarbons (PAHs) are hazardous environmental pollutants found in water, soil, and air. Exposure to this family of chemicals presents a danger to human health, and as a result, it is imperative to design methods that are able to detect PAHs in the environment, thus improving the quality of drinking water and agricultural soils. This review presents emerging immunoassay techniques used for in situ detection of PAH in water samples and how they compare to common-place techniques. It will discuss their advantages and disadvantages and why it is required to find new solutions to analyze water samples. These techniques are effective in reducing detection times and complexity of measurements. Immunoassay methods presented here are able to provide in situ analysis of PAH concentrations in a water sample, which can be a great complement to existing laboratory techniques due to their real-time screening and portability for immunoassay techniques. The discussion shows in detail the most relevant state-of-the-art surface functionalization techniques used in the field of immunosensors, with the aim to improve PAH detection capabilities. Specifically, three surface functionalization techniques are key approaches to improve the detection of PAHs, namely, substrate surface reaction, layer-by-layer technique, and redox-active probes. These techniques have shown promising improvements in the detection of PAHs in water samples, since they show a wider linear range and high level of sensitivity compared to traditional PAH detection techniques. This review explores the various methods used in the detection of PAH in water environments. It provides extra knowledge to scientists on the possible solutions that can be used to save time and resources. The combination of the solutions presented here shows great promise in the development of portable solutions that will be able to analyze a sample in a matter of minutes on the field.

Chemometric assisted determination of 16 PAHs in water samples by ultrasonic assisted emulsification microextraction followed by fast high-performance liquid chromatography with diode array detector

Combination of fast high-performance liquid chromatography–diode array detection (HPLC–DAD) technique and ultrasonic assisted emulsification micro-extraction (USAEME) as extraction method are used for simultaneous determination of sixteen polycyclic aromatic hydrocarbons (PAHs) in river samples. The optimum conditions of USAEME procedure are selected according to the literature. Due to presence of different chromatographic issues and the complexity of water matrices, multivariate curve resolution-alternating least squares (MCR-ALS) is a good resolution technique for simultaneous quantification of PAHs in standard and real samples. On this matter, region-based and whole chromatographic data analysis of 16 PAHs are done and the results are compared. Although the results of both methods were acceptable, region-based analysis had improvement regarding to the whole data analysis. Recoveries ranging from 81.80% to 105.86% and relative standard deviations (RSDs) less than 10% for all PAHs verified the precision and accuracy of this method. Also, the relative error of calibration curves (RE, %) were less than 14.69%. Also, analytical figures of merit using multivariate approach were used for whole and segment-based strategies. In this regard, the values of multivariate figures of merit in region-based analysis had better results compared to pseudo-univariate techniques and total analysis. These results confirmed that using second order calibration algorithms in USAEME–HPLC–DAD data is a powerful method for fast, cost effective and simple determination of PAHs in highly polluted samples.

Regional and Seasonal Variation of Polycyclic Aromatic Hydrocarbons in Water and Mollusca at Quarna North of Shatt AL-Arab River

Distribution and seasonal variations and sources of of the sixteen polycyclic aromatic hydrocarbons (PAHs) was studied in surface water and and fuor species of molluscs ( Theodoxus Jordani , Melanoides taberculata Melanopsis nodosa, Bellamya bengalensis ) from three stations at Al-Quarna in Shatt Al Arab river during the low tide period from September, 2018 to March, 2019 . Liquid-liquid extraction was used for water samples, while PAHs in molluscs were extracted using Soxhlet Extraction and finally analyzed by means of gas chromatography. physical and chemical parameter were measured such as . Water Temperature range from (13°C to 39°C), Dissolved oxygen range from (6.5 mg/l to 3.84 mg/l),PH range from (8.15-7.17) and Electrical conductivity (2.59 ms/cm- 4.75 ms/cm). Results of PAHs in water samples was ranged from (1.4754ng / l) during summer in the first station to (3.4215ng / l) during winter at the third station. While the total PAHs in molluscs range from 0.876 ng/g dry weight in the T .jordani in station 1during summer to 9.093 ng/g dry weight in the B.bengalensis during winter . The Highest concentration of PAHs in the four species were arranged as fellow : Bellamya bengalensis ˃ Melanopsis nodosa ˃ Melanoides taberculata ˃ Theodoxus Jordani. When we compares the concentration TPHs in water and molluscs with other study it allies within these concentration. Keywords: PAH, water, Mollusca, Pollution,Qurna,ShattAL-Arab River,Basrah,Iraq DOI : 10.7176/JNSR/9-14-05 Publication date :July 31 st 2019

Simple and effective dispersive micro-solid phase extraction procedure for simultaneous determination of polycyclic aromatic compounds in fresh and marine waters

In this work, we developed a simple, comprehensive, and effective device and procedure for sample preparation based on dispersive micro-solid phase extraction (d-μ-SPE) for the simultaneous determination of 30 polycyclic aromatic compounds or PACs (including 16 polycyclic aromatic hydrocarbons (PAHs), 3 quinones, and 11 nitro-PAHs) in water samples. The extraction/preconcentration step was carried out in a customized glass device (20–250 mL) using C18 as the sorbent. A mini-UniPrep syringeless filter was used as a desorption device, which allowed one-step desorption, filtration, and injection. The main factors affecting the d-μ-SPE were optimized using the Doehlert design. The optimal d-μ-SPE conditions were 100 mg of C18, 32 min of extraction at 1000 rpm, and 20 min of sonication (at the desorption step). The limit of detection (LOD) for PAHs and nitro-PAHs ranged from 0.8 ng L−1 (phenanthrene) to 1.5 ng L−1 (indene [1,2,3-cd]pyrene) and from 300 ng L−1 (2-nitrofluorene) to 500 ng L−1 (2-nitrobiphenyl), respectively. For quinones, it varied from 1.12 μg L−1 (1,4-naphthoquinone) to 1.70 μg L−1(9,10-phenanthrenequinone). Relative recoveries ranged from 59.1% (benzo[a]pyrene) to 110% (chrysene) for most PAHs and 68.9% (2-nitrofluorene) to 124% (1-methyl-6-nitronaphthalene) for the nitro-PAHs. The recoveries for quinones ranged from 65.3% (9,10-phenanthrenequinone) to 95.3% (9,10-anthraquinone). The enrichment factor varied from 213 (Nap) to 497 (Flu), from 39 (1,4-naphthoquinone) to 254 (9,10-anthraquinone), and from 122 (2-nitrobiphenyl) to 295 (1-methyl-4-nitronaphthalene) for the PAHs, nitro-PAHs, and quinones, respectively. After validation, the procedure was successfully applied toward the determination of PACs in river and marine water samples. Low-molecular-weight PAHs were detected with high frequencies (62.5–100%) and the total PAH concentration ranged from 2.30 ng L−1 (benzo[a]pyrene) to 1070 ng L−1 (pyrene). Quinones were found at concentrations ranging from below the LOD to up to 19.8 μg L−1. The proposed procedure was thus found to be comprehensive, precise, accurate, and suitable for determination of PACs in water samples.

Dispersive micro-solid phase extraction of 16 priority polycyclic aromatic hydrocarbons from water by using thermally treated clinoptilolite, and their quantification by GC-MS

The authors report on a novel sorbent (thermally treated natural zeolite; clinoptilolite) for use in dispersive micro-solid phase extraction (D-μ-SPE) of polycyclic aromatic hydrocarbons (PAHs) from water samples. The method was applied to the D-μ-SPE of 16 priority PAHs which then were quantified by gas chromatography with mass spectrometric detection (GC-MS). The method was validated in terms of specificity and selectivity, linearity and linear range, accuracy, precision, uncertainty, limits of detection and quantification. Figures of merit include (a) linear analytical ranges between 2.08 and 208ppb, and (b) detection limits in the range from 0.01 to 0.92ppb. The method was successfully applied to the determination of PAHs in river waters. Graphical abstract Schematic representation of dispersive micro-solid phase extraction (D-μ-SPE) of trace levels of PAHs in water samples by using thermally treated clinoptilolite as sorbent prior to gas chromatography-mass spectrometry analysis (GC-MS).

MXene/reduced graphene oxide hydrogel film extraction combined with gas chromatography–tandem mass spectrometry for the determination of 16 polycyclic aromatic hydrocarbons in river and tap water

In this study, MXene/reduced graphene oxide (MXene/rGO) hydrogel film, a novel nanomaterial was prepared and used as adsorbent for extraction of 16 polycyclic aromatic hydrocarbons (PAHs) in river and tap water prior to gas chromatography–tandem mass spectrometric analysis (GC–MS/MS). The properties of MXene/rGO hydrogel film were characterized by scanning electron microscope (SEM) and X-ray diffractometer (XRD). The PAHs in water samples were enriched with MXene/rGO, then eluted with n-hexane, finally separated with HP-5MS column (30 m × 0.32 mm, 0.25 μm), and finally detected by mass spectrometer with SIM mode. The method had linear ranges of 0.005–2.00 μg/L with the correlation coefficients greater than 0.995. The recoveries of the method ranged from 80.3% to 109.9%, with the relative standard deviations (RSDs) less than 10.01%. The limits of detection (LODs) were less than 0.005 μg/L. The method is simple, sensitive, precise, accurate, environmentally-friendly and it has been successfully applied to the determination of 16 PAHs in river and tap water samples.

A Low-Cost Approach Using Diatomaceous Earth Biosorbent as Alternative SPME Coating for the Determination of PAHs in Water Samples by GC-MS

In this study, the use of recycled diatomaceous earth as the extraction phase in solid phase microextraction (SPME) technique for the determination of polycyclic aromatic hydrocarbons (PAHs) in river water samples, with separation/detection performed by gas chromatography-mass spectrometry (GC-MS), is proposed. The optimized extraction conditions are extraction time 70 min at 80 °C with no addition of salt. The limits of quantification were close to 0.5 μg L−1 with RSD values lower than 25% (n = 3). The linear working range was 0.5 μg L−1 to 25 μg L−1 for all analytes. The method was applied to samples collected from the Itajaí River (Santa Catarina, Brazil) and the RSD values for repeatability and reproducibility were lower than 15% and 17%, respectively. The efficiency of the recycled diatomaceous earth fiber was compared with that of commercial fibers and good results were obtained, confirming that this is a promising option to use as the extraction phase in SPME.

Magnetic nanocomposite as sorbent for magnetic solid phase extraction coupled with high performance liquid chromatography for determination of polycyclic aromatic hydrocarbons

Magnetic composites-based adsorbents have received considerable attention in recent years due to their inherent superparamagnetic properties making them desirable for magnetic field assisted separation and enrichment. In this work, a novel magnetic adsorbent, Fe3O4@SiO2@MMTA-Au, was synthesized via 2-mercapto-4-methyl-5-thiazoleacetic acid bonding Au (MMTA-Au) deposited on Fe3O4@SiO2. The as synthesized core shell structured adsorbent, Fe3O4@SiO2@MMTA-Au magnetic nanocomposite was characterized with transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), Fourier transform-infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). This material was used as adsorbent of magnetic solid phase extraction (MSPE) to extract 14 polycyclic aromatic hydrocarbons (PAHs) of interest from water samples followed by the determination of their concentrations with high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD). The effects of four parameters of the MSPE were investigated, including the adsorbent mass, extraction time, extraction solvent and adsorption time. Under the optimized conditions, the enrichment factors (EFs) achieved were in the range of 80–98 and the detection limits were from 0.25 to 37.5 ng/L together with the good recoveries ranging from 87.8 to 120.0% of PAHs from water spiked. The developed method was successfully applied to the analysis of PAHs in water samples collected from river and rainfall.

Random initialisation of the excitation-emission matrix fluorescence spectral variables in constraint fashion for subsequent multivariate curve resolution alternating least square analysis on a peculiarly designed calibration set: Simultaneous sensing of nine polycyclic aromatic hydrocarbons in water samples

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic and mutagenic in nature therefore their sensing in water sample is an important analytical task. In the present work, a novel approach that is based on the random initialisation of the excitation-emission matrix fluorescence (EEMF) spectral variables in constraint fashion for subsequent multivariate curve resolution alternating least Square (MCR-ALS) analysis is introduced for simultaneously sensing the complex dilute aqueous mixture of PAHs. The usefulness of the proposed analytical approach is successfully demonstrated by applying it intentionally on a calibration set that is peculiar in many senses. The peculiarity mainly arises because the designed (i) the calibration set consist of nine PAHS having significant spectral overlap, (ii) the concentration of each PAH in different samples are kept constant and (iii) any two samples differ only in the presence and absence of the PAHs. The proposed approach is found to make precise and accurate estimation of each of the nine PAHs without involving any pre-separation. In summary, the proposed approach provides a simple and cost-effective procedure for simultaneous sensing of several PAHs in water samples. The proposed approach could be very useful in developing countries.

Bilayer Surfactants of Fatty Acid and Cetyltrimethylammonium Bromide on Magnetic Nanoparticles for Preconcentration of Polycyclic Aromatic Hydrocarbons in Water Samples

In this work, the highly dispersible sorbent in aqueous media, bilayer surfactants of fatty acid (FA) and cetyltrimethylammonium bromide (CTAB) coated on magnetic nanoparticles (MNPs), Fe3O4@FA@CTAB NPs, was synthesized successfully. It was used as sorbent for magnetic solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) in water samples. The extraction conditions including sorbent quantity, sample volume, adsorption time, elution solvent, and desorption time were investigated. The synthesized Fe3O4@FA@CTAB NPs could provide a high preconcentration factor and well dispersion in water samples because of the hydrophilic property of bilayer surfactants on MNPs. The extracted PAHs (phenanthrene, anthracene, and fluoranthrene) were determined by HPLC–UV technique using Waters Nova-Pak® C18 column and a mixture of acetonitrile, methanol, and deionized water (30/40/30) as mobile phase. The synthesized magnetic sorbent and the developed HPLC method were applied to determine PAHs in water samples. The extraction recoveries of PAHs in river water samples were achieved in the range of 71.78–118.29% with the RSD less than 4.70%. The limit of detection were 0.67, 0.10, and 0.53 μg L−1 for phenanthrene, anthracene, and fluoranthene, respectively. The results demonstrate that the developed method is suitable for rapid, simple, and inexpensive determination of PAHs in water samples.

Polycyclic Aromatic Hydrocarbons (PAHs) in the River Nile, Egypt: Occurrence and Distribution

ABSTRACTThe concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in surface water samples collected from three locations along the downstream of river Nile in Alexandria, Egypt were analyzed using gas chromatography–mass spectrometry. To the best of knowledge, this investigation represents one of the very few extensive studies investigating the distribution and sources of PAHs in water of river Nile in Egypt. Total concentrations of the 16 PAHs in water samples ranged from 235.92 ng L−1 at Abbis site (an agricultural area), which were predominated by three- and four-ring PAHs (about 90%) to 10367.60 ng L−1 at Al-Max area (a residential area with heavy traffic and fishing activities), which were predominated by five- to six-ring PAHs (about 94%). PAH concentrations were one to two orders of magnitude higher in comparison with those reported for riverine/estuaries systems around the world.Molecular indices, such as ratios of specific PAH compound including Phenanthrene/Anthracene (Phe/Ant) and Fluoranthene/Pyrene (Flua/Pyr), were calculated to evaluate the possible sources of PAHs and their relative importance. These ratios indicated that the major PAH input was from combustion of fuel, wood and grasses in the area under study (i.e. a pyrogenic source). The concentrations recorded in this investigation were higher than that recorded in the rivers of the USA and Europe and even higher than the levels established for drinking water in the USA.