Organic Compounds In Water Samples Research Articles

An integrated approach to evaluating water contaminants and evaporation in agricultural water distribution systems

This study presents an innovative approach for assessing water quality in agricultural irrigation networks, integrating stable isotope analysis, in vivo zebrafish screening, and comprehensive chemical profiling to investigate the occurrence, transformation, and potential toxicity of organic contaminants. Stable isotope analysis was used to measure evaporation as a proxy for water residence time in the canal, while liquid chromatography-high resolution mass spectrometry (LC-HRMS) identified a range of organic compounds in water samples collected from both the irrigation canal and its source river. Results indicated a reduction in contaminant levels in the canal compared to the river, with the most significant evaporation and concentration changes occurring at a holding reservoir, suggesting that managing residence time could help reduce water loss in arid irrigation networks. The data also highlighted how evaporation, particularly during the dry, hot season, influences contaminant dynamics. Hierarchical clustering of LC-HRMS results showed notable differences between the chemical profiles of canal and river samples, indicating that irrigation systems may contribute to the degradation or removal of certain compounds. Over 60 % of detected compounds were naturally derived, with anthropogenic contaminants like pesticides and personal care products further highlighting human impacts. Priority contaminants, including DEET and 2-naphthalene sulfonic acid, likely originated from urban activities upstream. Initial screening using zebrafish embryos showed bioactivity across sites, confirming the presence of contaminants needing further examination. Correlation analysis linked natural compounds to evaporation rates, suggesting that flora and fauna play significant roles in the chemical makeup of canal water. Overall, this approach provides a comprehensive framework for monitoring irrigation water, offering insights into contaminant behavior and supporting the development of standardized methods for assessing chemical fate and ecological risks in agricultural irrigation systems.

POLLUTION LEVEL OF OIL INDUSTRIAL WATER SAMPLES

Organic toxic compounds such as polycyclic aromatic hydrocarbons, phenolic compounds are a global environmental concern as they cause inflammation and skin cancer. As you know there are two types of anthropogenic sources of hydrocarbons: petrogenic and pyrogenic sources. Petrogenic sources include crude oil and petroleum-derived hydrocarbon compounds. Pyrogenic sources of hydrocarbon compounds are formed as a result of incomplete combustion of organic substances such as oil, wood, coal. Before entering the open sea these oil products pass through the entire coastal zone. It is known that industrial waters are discharged into reservoirs after various chemical processes. The aim of this work was to determine how dangerous industrial oil water is when it enters the aquatic ecosystem. The article investigates the chemical composition of wastewater from the oil industry and identifies organic toxic compounds - polycyclic aromatic hydrocarbons and phenolic compounds. At the same time, the amount of heavy metals in water samples was analyzed. For chemical analysis, 3 samples were taken from the territory of the refinery. In total, 15 polycyclic aromatic hydrocarbons, 13 phenolic compounds and 9 heavy metals were analyzed in water samples. Water samples were analyzed in accordance with the contract HS-153/2-18 between Heydar Aliyev Oil Refinery and Baku State University's Department of Ecological Chemistry. The chemical analyses of heavy metals, polycyclic aromatic hydrocarbons and phenolic compounds were carried out using extremely sensitive devices such as Perkin Elmer ICP/OES-2100DV and GC-MSD gas chromatograph 6890N with a highly efficient mass-selective detector-Agilent 5975. In the Khazar Ecological Laboratory performed quantitative analysis of organic compounds in water samples as well as heavy metal determination.

Micro-Solid Phase Extraction of Volatile Organic Compounds in Water Samples Using Porous Membrane-Protected Melamine-Modified MIL-88 Followed by Gas Chromatography-Mass Spectrometry

Melamine-modified MIL-88 was synthesized through the solvothermal method and utilized as the extracting device for the µ-solid phase extraction (µ-SPE) of selected volatile organic compounds (VOCs) including benzene, toluene, ethylbenzene, and isomers of xylene (BTEXs) from different environmental water samples. The prepared melamine-MIL-88 (Fe) was enclosed inside the porous hydrophilic tea bag filter membrane. The sealed membrane containing the sorbent (15 mg) was used as the µ-SPE device. The quantification of the extracted BTEXs was done by gas chromatography-mass spectrometry (GC-MS) instrument. The prepared sorbent was confirmed by different characterizations including powdered X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transformed infrared (FT-IR) spectroscopy. The method provided linearity range of 0.5–500.0 µg L−1 (depending on target analytes) and coefficients of determination (R 2) with the range of 0.9891–0.9981 under the optimum condition. The enrichment factors (EFs) were found to be between 39.0 and 48.0. The limits of detection (LODs) were also calculated to be between 0.08 and 0.42 µg L−1, while the range of corresponding absolute recoveries was in the range of 78–96%. The method relative standard deviations (RSDs) ranged from 5.5 to 11.8% (at 5.0 µg L−1). Moreover, the prepared melamine-MIL-88 (Fe) showed high adsorption capacity (130 mg g−1). The method is cost-effective, user-friendly, and with minimal consumption of organic solvent. In addition, melamine-MIL-88 has not yet been synthesized and investigated in the microextraction of the pollutants.

Halogenated Volatile Organic Compounds in Water Samples and Inorganic Elements Levels in Ores for Characterizing a High Anthropogenic Polluted Area in the Northern Latium Region (Italy).

This paper shows a characterization of the organic and inorganic fraction of river waters (Tiber and Marta) and ores/soil samples collected in the Northern Latium region of Italy for evaluating the anthropogenic/natural source contribution to the environmental pollution of this area. For organic compounds, organochloride volatile compounds in Tiber and Marta rivers were analyzed by two different clean-up methods (i.e., liquid–liquid extraction and static headspace) followed by gas chromatography–electron capture detector (GC-ECD) analysis. The results show very high concentrations of bromoform (up to 1.82 and 3.2 µg L−1 in Tiber and Marta rivers, respectively), due to the presence of greenhouse crops, and of chloroform and tetrachloroethene, due to the presence of handicrafts installations. For the qualitative and quantitative assessment of the inorganic fraction, it is highlighted the use of a nuclear analytical method, instrumental neutron activation analysis, which allows having more information as possible from the sample without performing any chemical-physical pretreatment. The results have evidenced high levels of mercury (mean value 88.6 µg g−1), antimony (77.7 µg g−1), strontium (12,039 µg g−1) and zinc (103 µg g−1), whereas rare earth elements show levels similar to the literature data. Particular consideration is drawn for arsenic (414 µg g−1): the levels found in this paper (ranging between 1 and 5100 µg g−1) explain the high content of such element (as arsenates) in the aquifer, a big issue in this area.

Evaluation of Heavy Metals and Organic Compounds in Water Samples Collected from Various Sources from Republic of Moldova and Romania

This work presents the study and determination of composition of natural water samples collected from five different types of water sources from Republic of Moldova and Romania: river, lake, spring, fountain and rain. The purpose of this study was to establish whether some of the heavy metals and organic compounds with impact on population health are present in drinking water samples and if their presence falls within the set limits by national regulations. The analysis has been performed using VIS spectrophotometer with RFID technology and individual parameter express cuvette tests for water analysis which allowed ensuring high accuracy of the measurements. Thus, over limits high rates of Pb2+ and Ni2+ have been found in all samples. A high concentration of F- was determined from fountain water - 2.92 mg/L and of Fe from river - 0.701 mg/L, which is twice than admissible values. The lowest concentration has been measured in the rainwater.

Evaluation of Heavy Metals and Organic Compounds in Water Samples Collected from Various Sources from Republic of Moldova and Romania

This work presents the study and determination of composition of natural water samples collected from five different types of water sources from Republic of Moldova and Romania: river, lake, spring, fountain and rain. The purpose of this study was to establish whether some of the heavy metals and organic compounds with impact on population health are present in drinking water samples and if their presence falls within the set limits by national regulations. The analysis has been performed using VIS spectrophotometer with RFID technology and individual parameter express cuvette tests for water analysis which allowed ensuring high accuracy of the measurements. Thus, over limits high rates of Pb2+ and Ni2+ have been found in all samples. A high concentration of F- was determined from fountain water - 2.92 mg/L and of Fe from river - 0.701 mg/L, which is twice than admissible values. The lowest concentration has been measured in the rainwater. Keywords: water samples, heavy metals, organic compounds

Polyethylene Terephthalate Nanofiber Sheet as the Novel Extraction Medium for the Determination of Phthalates in Water Samples.

A novel extraction medium was developed by packing polyethylene terephthalate (PET) nanofiber sheet having a diameter of 500 nm into a stainless-steel capillary of 0.8 mm inner diameter. The nanofiber was prepared by a carbon dioxide (CO2) laser supersonic multi-drawing method, which has a significantly higher surface area than the original PET fiber. A nanofiber sheet was prepared by winding the nanofibers. Extraction of phthalates in water samples by a PET nanofiber-packed extraction capillary was investigated using a conventional high-performance liquid chromatography (HPLC). Water samples were introduced into the extraction capillary with a low pressure. After extracting the water sample, the extraction capillary was directly connected to a six-port valve of HPLC with a PEEK nut, and the extracted analytes were desorbed, followed by injection to an HPLC system using a small amount of organic solvent. In this manuscript, the fundamental performance of the nanofiber sheet-packed extraction capillary for the extraction of organic compounds in water samples is quantitatively evaluated using a conventional HPLC system.

Ordered mesoporous carbon in solid-phase microextraction for analysis of volatile organic compounds in water samples

An ordered mesoporous carbon (OMC) film supported on graphite fiber was prepared by a dip-coating method combined with a solvent evaporation induced self-assembly (EISA) strategy.

Negative electrospray ionization ion mobility spectrometry combined with paper-based molecular imprinted polymer disks: A novel approach for rapid target screening of trace organic compounds in water samples

A novel approach for the rapid target screening of water contaminants in trace concentrations was applied for the determination of the artificial sweetener Acesulfame-K, an accepted municipal wastewater indicator. This new method combines the selective enrichment of target analytes on paper-based molecular imprinted polymer disks and the subsequent analysis using a modified ion mobility spectrometer allowing negative electrospray ionization (ESI-IMS). Our developed ion mobility spectrometer permits the sensitive detection of Acesulfame with a limit of detection of 93 µg L−1 within few seconds without sample separation. The use of modified paper filters for fast extraction and enrichment of the target substance from water samples results in a lower limit of detection of 0.19 µg L−1. This procedure is directly applicable in the field, the transport and the proper storage of bulky sample bottles is avoided. The capability of the procedure developed was demonstrated by measuring real samples from a river at locations upstream and downstream of the effluent of the central municipal waste water treatment plant. The quantitative data of ion mobility measurements show a very good agreement with those obtained with the commonly used standard procedure (high performance liquid chromatography-tandem mass spectrometry).

Control of disinfection byproducts (DBPs) by ozonation and peroxone process: Role of chloride on removal of DBP precursors

The objective of this study was to remove regulated DBP precursors by using ozonation and peroxone process (H2O2/O3). Regarding formation potentials of trihalomethanes (THMs) and haloacetic acids (HAAs), the role of chloride in chlorination and ozonation/peroxone processes was revealed. The organic compounds in water samples from rapid sand filtration preferably yielded the THM formation potentials, rather than HAAs. Ozonation with the typical applied doses (1–5 mg L−1) was ineffective for removals of THM and HAA precursors. The peroxone process only decreased the formation potentials of THMs. The reduction of THMs by the peroxone process resulted from decreases in either chloroform or dibromochloromethane. However, the limitation was found in the H2O2/O3 ratios of 2.0–3.0. The removals of HAA precursors were much more difficult than that of THM precursors by ozonation and peroxone processes. The oxidation of organic compounds was able to promote the HAA formations. Ozonation with the typical ozone doses increased the chloroform formations, while decreases in bromide-containing THMs occurred. Effect of ozonation on changes in HAAs speciation was unclear. The peroxone process likely promoted the dichloroacetic acids and trichloroacetic acids. The presence of chloride (1–5 g L−1) highly enhanced the THM and HAA formation potentials. NaCl addition greatly increased the bromide-containing THMs, while the chloroform decreased. For HAAs, the presence of chloride promoted the bromide-containing HAAs and monochloroacetic acids. The presence of chloride played a role as a promotor for strong chlorinating agents in chlorination, rather than as a scavenger in ozonation and peroxone processes.

Evaluation of a Cyclodextrin-silica Hybrid Microporous Composite for the Solid-phase Extraction of Polycyclic Aromatic Hydrocarbons.

Solid-phase extraction (SPE) coupled with high-performance liquid chromatography (HPLC) with fluorescence detection were employed to determine trace polycyclic aromatic hydrocarbons in water samples. In this way, the use of cartridges containing cyclodextrin-silica hybrid microporous solid phases was proposed. The experimental results indicated that the method provided relative standard deviations of below 15% and detection limits recorded were 12, 1.2, 12, 38, 4, 6 and 4 ng L(-1) for benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[g,h,i]perylene, indeno[1,2,3]pyrene, benzo[a]pyrene, dibenzo[a,h]anthracene and benzo[a]anthracene, respectively. Moreover, the method was successfully applied for the determination of these organic compounds in water samples, where they were found to be in the 7 to 580 ng L(-1) range. It can be concluded that the major advantages of cyclodextrin-silica hybrid microporous solid phases are that they reduce the consumption and the toxicity of the solvent and the time consumption of the sample treatment step.

Determination of very volatile organic compounds in water samples by purge and trap analysis with a needle-type extraction device

Very volatile organic compounds (VVOCs), such as methanol, acetaldehyde, ethanol, acetone, acetonitrile, and dichloromethane, were extracted from water samples using a needle-type extraction device based on purge and trap analysis. The extracted analytes could then be determined by gas chromatography–mass spectrometry. By introducing carbon molecular sieves as the extraction medium, aqueous VVOCs could be successfully extracted using the extraction needle. The limit of quantification for methanol, acetaldehyde, ethanol, acetone, acetonitrile, and dichloromethane were 75, 75, 7.5, 0.5, 10 and 0.5μg/L, respectively. This newly developed method was also successfully applied to the determination of VVOCs in commercial samples, such as fruit juice.

Evaluation of polycaprolactone as a new sorbent coating for determination of polar organic compounds in water samples using membrane-SPME.

Commercially available solid-phase microextraction fibers used for isolation of polar analytes are based on the adsorption phenomenon. In consequence, typical limitations bonded with analytes displacement and matrix effects are very frequent. In the present study, alternative solution is described. Polycaprolactone (PCL) was used for the first time as sorbent to isolate polar organic compounds from water samples using the membrane–solid-phase microextraction (M-SPME) technique. In this technique, due to protective role of the mechanically and thermally stable polydimethylsiloxane (PDMS) membrane, internal polar coating might be melted during extraction and desorption of analytes. In consequence sorbents with low melting points like a PCL might be utilized. Based on chromatographic retention data, triazines were selected as a model compounds for evaluation of the sorptive properties of the polycaprolactone. Applying the screening plan and central composite design, statistically significant parameters influencing extraction efficiency were determined and optimized. The analysis of variance confirmed the significant influence of temperature, salt content, and pH of samples on the extraction efficiency. Besides the new PCL/PDMS fiber, a commercial fiber coated with divinylbenzene/polydimethylsiloxane (DVB/PDMS) was used for comparative studies. The results obtained showed that PCL is an interesting sorbent which can be successfully applied for isolation of polar organics from aqueous matrices at a broad range of analytes concentration. The determined detection limits of procedure based on the novel fiber enable its application at the concentration levels of triazines recommended by the US EPA standards. The practical applicability of the developed fiber has been confirmed by the results based on the analysis of real samples.

Comprehensive Analytical Method for Semi-volatile Organic Compounds in Water Samples by Combination of Disk-type Solid-phase Extraction and Gas Chromatography-Mass Spectrometry Database System

A disk-type solid-phase extraction method for simultaneous extraction of a wide range of semi-volatile organic compounds in water samples was developed. The developed method could extract 186 out of 202 model compounds from spiked environmental samples (0.1 μg/L) with 94% average recovery (50-111%). Compared with the previous cartridge-type method, the extraction time was reduced to approximately 1/6. Applying the combination of the developed method and the database system to environmental samples for non-target analyses, 39 micro-pollutants with a wide range of physicochemical properties were determined.

Chemometrics Optimization of Volatile Organic Compounds Analysis in Water by Static Headspace Gas Chromatography Mass Spectrometry

Static headspace coupled with gas chromatography-mass spectrometry was applied to extraction and analysis of volatile organic compounds in water samples. The effects of various factors affecting on the extraction efficiency including: the extraction temperature, extraction time, salt concentration and stirring speed were carried out by means of a 2 4 full factorial design. It was found that the effects of extraction temperature and salt concentration were signi fi cant. Then, a central composite design was performed to optimize the level of these factors. The optimal headspace conditions were achieved when the vials were heated under 88°C and 29% w/w addition of salt. At optimum operating conditions, analytical figures of merit of method such as linearity (0.9962-0.9996), repeatability (1.2-12.13%), detection limits (0.1-4.9 μg.L −1 ) and linearity dynamic range (10-1000 μg.L −1 ) were determined. The proposed methods can be used to direct investigation of the presence of Volatile organic compounds in environmental samples without pre-treatment of samples. Finally the optimized method was used to investigate the existence of volatile organic compounds in Babolroud River in the north of Iran.

Determination of volatile organic compounds in water samples using membrane-solid phase microextraction (M-SPME) (headspace version)

The results of a study on the use of membrane-solid phase microextraction (M-SPME) for sampling volatile organic compounds (VOCs) from the headspace above the liquid medium are presented. The sampled VOCs were subsequently quantified by gas chromatography (GC). Two systems were compared in this study, i.e. a novel two-phase sorption system (M-SPME), and a commercial fibre. Headspace sampling using SPME was optimized with respect to sample temperature, extraction time and the content of a salting-out agent (independently vs. each parameter). Under the optimized conditions, extraction with the M-SPME fibre yielded a limit of detection (LOD) of 0.011 µg L(-1). This value is comparable with LOD achieved with a commercial fibre under its own optimum conditions. However, using the M-SPME sample preparation procedure developed in this work, a broad linear range from 0.5 to 100 µg L(-1) was obtained, while isolation with a commercial fibre resulted in a linear range up to ca. 25 µg L(-1) only. Finally, the suitability of the novel fibre for VOC determination was proved by conducting measurements on real samples.

Preparation of magnetic core mesoporous shell microspheres with C18-modified interior pore-walls for fast extraction and analysis of phthalates in water samples

In this study, core–shell magnetic mesoporous microspheres with C18-functionalized interior pore-walls were synthesized through coating Fe 3O 4 microspheres with a mesoporous inorganic–organic hybrid layer with a n-octadecyltriethoxysilane (C18TES) and tetraethyl orthosilicate (TEOS) as the silica source and cetyltrimethylammonia bromide (CTAB) as a template. The obtained C18-functionalized Fe 3O 4@ mSiO 2 microspheres possess numerous C18 groups anchored in the interior pore-walls, large surface area (274.7 m 2/g, high magnetization (40.8 emu/g) and superparamagnetism, uniform mesopores (4.1 nm), which makes them ideal absorbents for simple, fast, and efficient extraction and enrichment of hydrophobic organic compounds in water samples. Several kinds of phthalates were used as the model hydrophobic organic compounds to systematically evaluate the performance of the C18-functionalized Fe 3O 4@ mSiO 2 microspheres in extracting hydrophobic molecules by using a gas chromatography–mass spectrometry. Various parameters, including eluting solvent, the amounts of absorbents, extraction time and elution time were optimized. Hydrophobic extraction was performed in the interior pore of magnetic mesoporous microspheres, and the materials had the anti-interference ability to macromolecular proteins, which was also investigated in the work. Under the optimized conditions, C18-functionalized Fe 3O 4@ mSiO 2 microspheres were successfully used to analyze the real water samples. The results indicated that this novel method was fast, convenient and efficient for the target compounds and could avoid being interfered by macromolecules.

Directly suspended droplet microextraction in a rotating vial

In this paper, a novel suspended droplet microextraction method was developed for the detection of trace of organic compounds in water samples. The process was executed in a rotating extraction vial without the use of a stir bar. A single drop of octan-1-ol placed on top of the water sample was used as the solvent. The droplet remained on top of the water sample as a thin layer with an expanding surface area during the extraction stage, while during the sampling stage, the droplet was collected and sampled by inserting a needle. The volume of the microdroplet used was 3 μL or less, to ensure high organic compound sensitivity. The microextraction experimental setup was simple, utilizing centrifugal forces and possesses the advantages of low cross-contaminant/interference and applicability to water samples apt to emulsification. Nitrobenzene was selected as a model organic compound, and samples were analyzed using gas chromatography (GC) or UV–vis spectrometry. Analysis of the microextraction method results showed a relative standard deviation (RSD) less than 3.82%.

Response Surface Optimization for Determination of Volatile Organic Compounds in Water Samples by Headspace-Gas Chromatography--Mass Spectrometry Method

The determination of benzene, toluene, p-xylene, tetrachloroethene, chlorobenzene, and dibromomethane in water by headspace analysis combined with gas chromatography-mass spectrometry (HS-GC-MS) has been investigated. An optimization strategy for the analysis of the six volatile organic compounds (VOCs) is presented with the experimental design and response surface methodology aid. Thermostatting time, temperature, and salt quantity were optimized by using a central composite design, and quadratic models relating peak areas to the three factors were built. The mathematical models were tested on a number of simulated data set and had a coefficient of R2>0.98. The factor effects were visualized as three-dimensional response surfaces and contour plots. The optimal conditions were achieved in 36.8 min, at 90 degrees C, and with 6 g of NaCl. The method showed a good agreement between the experimental data and predictive values throughout the studied parameter space, and was suitable for optimization studies of the VOCs in water by the HS-GC-MS method.

Survey on 882 Organic Micro-Pollutants in Rivers throughout Japan by Automated Identification and Quantification System with a Gas Chromatography-Mass Spectrometry Database

We have developed a comprehensive analytical method for nearly 900 semi-volatile organic compounds in water samples utilizing an automated identification and quantification system with a gas chromatography - mass spectrometry database (AIQS-DB). To verify the usefulness of the comprehensive method and to clarify the status of chemical pollution of rivers throughout Japan, we surveyed 882 semi-volatile organic compounds. In the farming season (May to August) in 2005, samples were taken in the middle and lower reaches of 11 rivers flowing through urban and rural areas. The number of chemicals per sample ranged from 0 to 78 (median 15), and 188 of the 882 analytes were detected at least once. Seventy-five chemicals, including 10 pesticides, were found with above 10 % frequency; four pharmaceuticals and personal care products were detected with above 40 % frequency. The total per-sample analyte load ranged from 0 to 819 μg /L (median 3.1). Although no chemical was present in concentrations greater than specified in drinking-water guidelines and environmental standards, 14 substances exceeded the predicted no-effect concentrations for aquatic life. Since a large number of chemical concentrations were able to be obtained by the comprehensive method, we were able to plot pollution profile which is useful in giving an overall picture of chemical pollution in the survey site. From pollution profiles obtained in this survey, it was confirmed that the main pollution sources in Japanese rivers are household, business, and agricultural activities, not industrial activities. The results confirmed that our comprehensive method utilizing the AIQS-DB is a powerful and useful tool for evaluating chemical pollution in the environment.