Determination of Chlorophenols in Water Samples Using Solid-Phase Extraction Enrichment Procedure and Gas Chromatography Analysis

Development of a Paper-Based Disposal Thin-Film Solid-Phase Microextraction Tool for the Quantification of Environmentally Hazardous 4-Chlorophenol in Water

The presence of chlorinated compounds in water resources presents various environmental and health risks. Therefore, there is a precise need to develop a potential technique for fast and efficient monitoring of chlorinated contaminants in water due to environmental protection and regulation compliance. Here, we designed a paper-based thin-film solid-phase microextraction (TF-SPME) patch to estimate 4-chlorophenol (4-CRP), a widely known environmentally hazardous pollutant in water samples. We fabricated the microextraction patch on the paper support utilizing the thin film applicator for uniform coating using divinylbenzene, polydimethylsiloxane, and a multiwalled carbon nanotube (MW-CNT) composite recipe. To check the performance of our fabricated tool, we directly exposed the TF-SPME patches to standard solutions with various concentrations of 4-CRP in water and finally quantified the analyte by exploiting the gas chromatography-mass spectrometer. Our experiments demonstrated the high extraction efficiency of the paper-based TF-SPME analytical tool for the estimation of 4-CRP in water with a limit of detection of ∼10 ng/mL, suggesting the practical applicability of the technique to monitor the analyte within the recommended range. To check the feasibility of the proposed technique for rapid determination, we performed the calibration curve of the analyte in the concentration range of 100-10,000 ng/mL and finally derived the curve fitting equation for the estimation of an unknown amount of 4-CRP. This study demonstrated the feasibility of using a simple paper-based thin-film solid-phase microextraction patch as a sampling kit for monitoring the environmentally hazardous 4-CRP pollutant from water. In the future, the proposed analytical method may be useful for the rapid quantification of chlorinated compounds from the water matrix.

Chlorophenols in environment: Recent updates on pretreatment and analysis methods

Chlorophenols (CPs) are widely used in industries such as petrochemicals, insecticides, pharmaceuticals, synthetic dyes and wood preservatives. However, owing to the improper discharge and disposal, they have become major contaminants that are ubiquitously distributed in water, soil, and sewage sediments, posing a significant threat to ecosystems and human health. Consequently, accurate, sensitive and effective pretreatment and analysis methods for CPs are urgently required and have been actively explored in recent years. This review encompasses the pretreatment and detection methods for CPs in environmental samples from 2010 to 2024. The pretreatment methods for CPs primarily include solid-phase extraction, liquid-liquid extraction, solid-phase microextraction, liquid-phase microextraction, and QuEChERS. These methods are evolving towards more effective and environmentally friendly technologies, such as the miniaturization and automation of equipment, the development of innovative materials (including graphene, molecularly imprinted polymers, layered double hydroxides, porous organic polymers, and porous carbon), and the use of green solvents like deep eutectic solvents. Detection methods emphasize liquid chromatography-mass spectrometry, gas chromatography-mass spectrometry, sensors, and capillary electrophoresis. Advances in chromatographic columns, novel ion sources, and high-resolution mass spectrometry have significantly improved detection performance. In addition, the pros and cons of diverse techniques, critical comments and future perspectives are elaborated.

Determination of Pentachlorophenol in Seafood Samples from Zhejiang Province Using Pass-Through SPE-UPLC-MS/MS: Occurrence and Human Dietary Exposure Risk

Pentachlorophenol (PCP) has attracted wide attention due to its high toxicity, persistence, and bioaccumulation. In this study, a sensitive UPLC-MS/MS method for the determination of PCP in seafood samples was developed and validated. The samples were ultrasonic extracted with acetonitrile containing 1% acetic acid-acetonitrile and followed by using a pass-through solid-phase extraction (SPE) cleanup on Captiva EMR-Lipid cartridges. The linearity of this method ranged from 1 to 1000 μg/L, with regression coefficients of >0.99. The detection limit and quantitation limit were 0.5 μg/kg and 1.0 μg/kg, respectively. The recoveries in different types of seafood samples ranged from 86.4% to 102.5%, and the intra-day and inter-day relative standard deviations (RSDs) were 3.7% to 11.2% and 2.9% to 12.1%, respectively (n = 6). Finally, the method has been successfully utilized for the screening of PCP in 760 seafood samples from Zhejiang Province. PCP was detected in 5.8% of all seafood samples, with the largest portion of detections found in shellfish, accounting for approximately 60% of the total. The average concentrations detected ranged from 1.08 to 21.49 μg/kg. The non-carcinogenic risk indices for adults and children who consume PCP ranged from 10-4 to 10-3 magnitudes. All of these indices stayed significantly below 1, implying that the health risk from PCP in marine organisms to humans is minimal.

The Separation of Chlorobenzene Compounds from Environmental Water Using a Magnetic Molecularly Imprinted Chitosan Membrane

In this work, a magnetic molecularly imprinted chitosan membrane (MMICM) was synthesized for the extraction of chlorobenzene compounds in environmental water using the membrane separation method. The optimal extraction amount for chlorobenzene (9.64 mg·L⁻¹) was found to be a 1:2 solid to liquid ratio, with a 20 min extraction time and 35 °C extraction temperature. This method proved to be successfully applied for the separation and trace quantification of chlorobenzene compounds in environmental water, with the limit of detection (LOD) (0.0016–0.057 ng·L⁻¹), limit of quantification (LOQ) (0.0026–0.098 ng·L⁻¹), and the recoveries ranging (89.02–106.97%).

Fluorescence determination of chloramphenicol in milk powder using carbon dot decorated silver metal-organic frameworks

Carbon dot decorated silver metal-organic frameworks (CD-MOFs) were successfully synthesized at room temperature by adding CDs during the formation of Ag-MOFs. The CD-MOFs have excellent optical property, stability, and good fluorescence intensity in water compared with other solvents. The fluorescence intensity of CD-MOFs was relatively stable in the range of pH 5-9. It was used to construct a sensitive and reliable fluorescent sensor for the determination of chloramphenicol (CAP). When the CAP was introduced into the CD-MOFs, the fluorescence at 427 nm was quenched at the excitation wavelength of 332 nm. Wide linear relationships were established for CAP with a limit of detection of 44 nM. The fluorescent sensor has been applied to determine CAP in milk powder sample with satisfied recoveries (104 to 109%) and good precision (< 4%). The photoinduced electron-transfer is the most important mechanism contributing to the fluorescence quenching. The synthesized CD-MOFs provide a new orientation for fluorescence determination of chloramphenicol in real samples.

Presence of Disinfection Byproducts in Public Swimming Pools in Medellín, Colombia

The quality of water in swimming pools is essential to avoid risks to the health of users. Medellín has more than 1000 public swimming pools, which are supervised by the Medellín Health Authority to monitor and ensure compliance with relevant regulations. The Health Authority has financed several studies related to the quality of drinking and recreational water in Medellín in order to protect consumers and users. One such study involves the evaluation of the presence of disinfection byproducts (DBP). The best known DBPs resulting from disinfection with chlorine are trihalomethanes (THMs) and halogenated acetic acids (HAAs), as well as other minorities such as chloramines or halophenols (HPs). DBPs pose a greater risk in swimming pool water because there is a greater possibility of ingestion, since exposure occurs through several routes at the same time (direct ingestion of water, inhalation of volatile or aerosol solutes, dermal contact and absorption through skin). In the present work, high concentrations of THMs and HAAs were detected in the public swimming pools selected in the study, but the presence of HPs was not detected in the pools.

Sorption Properties of Polydivinylbenzene Polymers towards Phenolic Compounds and Pharmaceuticals

Highly cross-linked polymers are commonly used in purification and separation techniques because of their many useful features. In order to better adjust their porosity to adsorption of specific compounds, methods like surface functionalization or imprinting are used. In this work, a series of highly cross-linked polydivinylbenzenes (pDVB) were prepared using a suspension method. Toluene was applied as a pore-forming diluent. Some part of toluene (1 mL) was replaced with phenol (F), 2,4,6-trichlorophenol (T) or their mixture (M) to prepare polymers with porosity more suitable for phenols sorption. Another approach was an introduction of sulfone groups onto the polymer surface (pDVB-SO3H). The physicochemical characteristics of the synthetized adsorbents included CHN, FTIR, DSC and porosimetric analyses. Afterwards, to evaluate sorption properties of the prepared adsorbents towards phenols, ibuprofen and salicylic acid the solid phase extraction (SPE) experiments were performed. The polymers had the specific surface areas of about 440–560 m2/g created mainly by mesopores with widths ca. 3.75 and 4.75–7.15 nm. Materials obtained with the addition of porosity modifiers (phenol, trichlorophenol, mixture) had more uniform porous structure and their sorption capacity toward phenols increased ca. 5%. Similar sorption capacities were obtained for ibuprofen. Salicylic acid had low affinity to the surface of the tested polymers.

Application of polyethyleneimine-modified attapulgite for the solid-phase extraction of chlorophenols at trace levels in environmental water samples

A polyethyleneimine (PEI)-modified attapulgite was employed as a new adsorbent for solid-phase extraction (SPE) of chlorophenols (CPs) from environmental water samples. Key factors pivotal to extraction efficiency, such as organic additive, pH, salt, sample loading volume, elution volume, and sample loading flow rate, were investigated. The maximum adsorption capacity of CPs reached 38 mg/g, and the adsorption behavior could be described with the Langmuir isotherm model. The developed SPE procedure was then tested on river water samples. Of this cartridge, 0.4 g could be used to treat up to 100 mL of the water sample, with high recoveries achieved. The limit of detection (S/N = 3) and the limit of quantification (S/N = 10) were in range of 0.08-0.56 and 0.27-1.88 ng/mL, respectively. The mean recoveries of CPs spiked in river water samples ranged from 84.4 to 96.8% with relative standard deviations for the intra-day and inter-day less than 6.30%. The developed SPE method exhibited high sensitivity, high selectivity, excellent accuracy, and good repeatability to the analysis of trace CPs in complicated aqueous matrices. Graphical abstract Graphical abstract contains poor quality and small text inside the artwork. Please do not re-use the file that we have rejected or attempt to increase its resolution and re-save. It is originally poor, therefore, increasing the resolution will not solve the quality problem. We suggest that you provide us the original format. We prefer replacement figures containing vector/editable objects rather than embedded images. Preferred file formats are eps, ai, tiff and pdf.The separated figures were attached, which named Graphical abstract. ᅟ.