Determination of phthalates in bottled water by automated on-line solid phase extraction coupled to liquid chromatography with uv detection

Phthalate esters in clothing: A review

Phthalate esters (PAEs) are widely used as plasticizers to enhance the flexibility and durability of different consumer products, including clothing. However, concerns have been raised about the potential adverse health effects associated with the presence of phthalates in textiles, such as endocrine disruption, reproductive toxicity and potential carcinogenicity. Based on examination of more than 120 published articles, this paper presents a comprehensive review of studies concerning the phthalate content in clothing and other textile products, with special emphasis on those conducted in the last decade (2014-2023). The types and role of PAEs as plasticizers, the relevant legislation in different countries (emphasizing the importance of monitoring PAE levels in clothing to protect consumer health) and the analytical methods used for PAE determination are critically evaluated. The review also discusses the models used to evaluate exposure to PAEs and the associated health risks. Finally, the study limitations and challenges related to determining the phthalate contents of textile products are considered.

Emerging organic contaminants in drinking water systems: Human intake, emerging health risks, and future research directions

Few earlier reviews on emerging organic contaminants (EOCs) in drinking water systems (DWS) focused on their detection, behaviour, removal and fate. Reviews on multiple exposure pathways, human intake estimates, and health risks including toxicokinetics, and toxicodynamics of EOCs in DWS are scarce. This review presents recent advances in human intake and health risks of EOCs in DWS. First, an overview of the evidence showing that DWS harbours a wide range of EOCs is presented. Multiple human exposure to EOCs occurs via ingestion of drinking water and beverages, inhalation and dermal pathways are discussed. A potential novel exposure may occur via the intravenous route in dialysis fluids. Analysis of global data on pharmaceutical pollution in rivers showed that the cumulative concentrations (μg L-1) of pharmaceuticals (mean ± standard error of the mean) were statistically more than two times significantly higher (p = 0.011) in South America (11.68 ± 5.29), Asia (9.97 ± 3.33), Africa (9.48 ± 2.81) and East Europe (8.09 ± 4.35) than in high-income regions (2.58 ± 0.48). Maximum cumulative concentrations of pharmaceuticals (μg L-1) decreased in the order; Asia (70.7) had the highest value followed by South America (68.8), Africa (51.3), East Europe (32.0) and high-income regions (17.1) had the least concentration. The corresponding human intake via ingestion of untreated river water was also significantly higher in low- and middle-income regions than in their high-income counterparts. For each region, the daily intake of pharmaceuticals was highest in infants, followed by children and then adults. A critique of the human health hazards, including toxicokinetics and toxicodynamics of EOCs is presented. Emerging health hazards of EOCs in DWS include; (1) long-term latent and intergenerational effects, (2) the interactive health effects of EOC mixtures, (3) the challenges of multifinality and equifinality, and (4) the Developmental Origins of Health and Disease hypothesis. Finally, research needs on human health hazards of EOCs in DWS are presented.

Determination of partition coefficients of phthalic acid esters between polydimethylsiloxane and water and its field application to surface waters

Phthalic acid esters (PAEs) or phthalates are endocrine-disrupting chemicals and among the most frequently detected hydrophobic organic pollutants, which can be gradually released from consumer products into the environment (e.g., water). This study measured the equilibrium partition coefficients for 10 selected PAEs, with a wide range of logarithms of the octanol-water partition coefficient (log K_ow) from 1.60 to 9.37, between poly(dimethylsiloxane) (PDMS) and water (K_PDMSw) using the kinetic permeation method. The desorption rate constant (k_d) and K_PDMSw for each PAEs were calculated from kinetic data. The experimental log K_PDMSw for the PAEs ranges from 0.8 to 5.9, which is linearly correlated with log K_ow values up to 8 from the literature (R² > 0.94); however, it slightly deviated for the PAEs with log K_ow values greater than 8. In addition, K_PDMSw decreased with the temperature and enthalpy for PAEs partitioning in PDMS-water in an exothermic manner. Furthermore, the effects of dissolved organic matter and ionic strength on the partitioning of PAEs in PDMS were investigated. PDMS was used as a passive sampler to determine the aqueous concentration of plasticizers in river surface water. The results of this study can be used to evaluate the bioavailability and risk of phthalates in real environmental samples.

Occurrence of microplastics in tap and bottled water, and food packaging: A narrative review on current knowledge

Nowadays, microplastic has been detected in many environmental samples, including aquatic and terrestrial environments. However, few studies recently have addressed their attention to microplastic contamination in different drinking sources and food packages. This review paper has narrated those few findings in brief. Literature showed that different pieces of microplastic fragments, e.g., polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyethylene (PE), high-density polyethylene (HDPE), low-density polyethylene (LDPE), etc. are detected in plastic drinking bottle, tap water, and food packaging containers. Microplastic fragmentation may be associated with mechanical stress, UV radiation, low plastic material quality, aging factor, and atmospheric deposition. Besides these, microplastic is a hub of different chemical compounds and can also retain other complex materials from the surroundings. This makes the microplastic contamination even more complicated and difficult to detect them accurately in a single method. Additionally, one of the common practices at the community level is the long-time repeated usage of plastic drinking bottles and food boxes that subsequently cause microplastic leaching and potential health threats to consumers. This narrative study summarizes the current scenario of microplastic contamination from drinking bottles and food containers and emphasizes doing more quality research in this subtle but highly imposed field to understand potential exposure better.

Simultaneous determination of phthalates and bisphenols from plastic bottled water samples by dispersive solid-phase extraction with multiwalled carbon nanotubes and liquid chromatography/atmospheric pressure photoionization/high-resolution mass spectrometry

RATIONALE

Phthalates and bisphenols were reported as endocrine disrupting chemicals and hence a potential threat to human health. Polyethylene terephthalate bottles are being used to store drinking water and the probability of migration of phthalates and bisphenols from the bottles into the water is high. The migration of analytes with respect to different storage conditions need to be studied.

METHOD

A sensitive analytical method for simultaneous determination of seven phthalates and three bisphenols from packaged drinking water was developed using liquid chromatography/atmospheric pressure photoionization/high-resolution mass spectrometry. The analytes were extracted by dispersive solid-phase extraction by multiwalled carbon nanotubes.

RESULTS

The developed method showed linearity from 0.5 to 5000 μg/L with the limit of detection and limit of quantification ranging from 0.5 to 1 μg/L and 1 to 2 μg/L, respectively, for phthalates and bisphenols. The inter- and intraday variations were below 10%. The recoveries were in the range of 79.5% to 112%. The migration of phthalates and bisphenols increased with storage time and temperature. Maximum migration was observed for diisobutyl phthalate of 1209.7 ng/L followed by dibutyl phthalate at 777.8 ng/L on 180 days of analysis at room temperature. Migration of bis(2-ethylhexyl) phthalate was observed to be higher at elevated temperatures, increasing from 14.9 to 514 ng/L. Similarly, migration of bisphenol-A was increased at 45°C. The results were subjected to analysis of variance (ANOVA) studies and the results showed significant variations of phthalates and bisphenols with respect to storage temperature and time.

CONCLUSION

The use of atmospheric pressure photoionization facilitated simultaneous determination of phthalates and bisphenols. The migration of phthalates and bisphenols increased with increasing temperature and storage time. Maximum migration was observed for diethyl, diisobutyl, dibutyl and bis(2-ethylhexyl) phthalates. This may be attributed to the type of plastic, the processing parameters and recycling.

Rapid determination of phthalates in paper products by supercritical fluid chromatography / tandem mass spectrometry

Phthalic acid esters (PAEs) are widely used as components of industrial and consumer products including paper and cardboard packaging materials contacting with food or human skin. Being endocrine-disrupting chemicals, PAEs have a negative effect on human health and must be controlled in pulp and paper products. In the present study, supercritical fluid chromatography - tandem mass spectrometry in combination with pressurized liquid extraction was proposed for PAEs determination in such objects. Octadecyl stationary phase with non-endcapped silanol groups ensured rapid (4 min) separation of the ten priority PAEs in isocratic elution mode and allowed for effective elimination of interferences from the trace impurities of PAEs in the mobile phase. The attained LOQs are in the range of 0.7-10 μg/L in extracts and 0.02-0.3 μg/g in paper and cardboard samples. The developed method is distinguished by analysis rapidity, easy sample preparation procedure, high selectivity, low susceptibility to mobile phase contamination with analytes, low cost and environmental friendliness due to the use of carbon dioxide as a main component of the mobile phase. The method was successfully tested on real samples of toilet paper and food packaging paper and cardboard in which eight analytes were found at the levels of 0.03-43.5 μg/g. This article is protected by copyright. All rights reserved.

Fabrication of magnetic covalent organic framework for efficient extraction and determination of phthalate esters in milk samples

Using two monomers of 4,4″-diamino-p-terphenyl and 1,3,5-triformylphloroglucinol, a co-precipitation structured magnetic covalent organic framework adsorbent was fabricated. After that, a high efficient vortex-assisted magnetic solid-phase extraction method was developed prior to gas chromatography-tandem mass spectrometry analysis for the determination of phthalate esters in milk samples. The fabricated magnetic adsorbent was facilely fabricated, fully characterized, and exhibited high extraction efficiency, which can be attributed to its larger pore size as well as strong hydrophobic and π-π stacking interactions between adsorbent and phthalate esters. Key parameters affecting extraction efficiency were investigated. Under the optimized conditions, the proposed method possessed good linearity (3.0-1000 μg/L), high sensitivity (0.8-2.1 μg/L for limits of detection), and satisfactory recoveries (76.8%-99.2%). The relative standard deviations for intra-day was 3.1%-4.5% and inter-day was 3.3%-6.1%. This work is suitable for high efficient separation/preconcentration of phthalate esters in milk samples.

Facile synthesis and evaluation of three magnetic 1,3,5-triformylphloroglucinol based covalent organic polymers as adsorbents for high efficient extraction of phthalate esters from plastic packaged foods

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A facile synthetic route for synthesis of three magnetic Tp-based COPs adsorbents was provided.

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Magnetic COP2 showed best extraction performance for PAEs.

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The potential adsorption mechanism was systematically investigated.

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This method was suitable for high efficient extraction of hydrophobic PAEs from foods.

Three covalent organic polymers (COPs) were successfully fabricated by room-temperature solvent-free mechanochemical grinding method between 1,3,5-triformylphloroglucinol (TP) and p-phenyl enediamine (COP1), benzidine (COP2), 4, 4″-diamino-p-terphenyl (COP3), and followed by coprecipitation on the surface of Fe₃O₄ nanoparticles to form three corresponding magnetic Tp-series COPs. The fabricated magnetic COPs were evaluated and then applied for the extraction of phthalate esters from food samples before gas chromatography-tandem spectrometry analysis. Magnetic COP2 exhibited the highest extraction efficiency, which can be attributed to its larger pore size, and its strong hydrophobic and π-π interactions with phthalate esters. The method possessed good linearity (10–1000 μg·kg⁻¹), high sensitivity (0.29–2.59 µg·kg⁻¹ for LODs and 0.97–8.63 µg·kg⁻¹ for LOQs), and satisfactory recoveries (70.2–108.1%) with relative standard deviations lower than 5.2%. This method has potentials for high efficient separation/preconcentration of hydrophobic phthalate esters from foods.

Initial phthalates fingerprint and hydrochemical signature as key factors controlling phthalates concentration trends in PET-bottled waters during long storage times

Phthalateacid esters (PAEs) concentration in bottled water and different factors (water pH, storage time, sunlight exposure, and temperature) that affect/control them have become hot topics during recent years. Nevertheless, quite contradictory results and disagreements on the effects of these factors have been published. In an attempt to find some consensus on this topic, a comprehensive study considering the combined effect of long storage times (longer than a year) and the water hydrochemical signature (including water pH, elemental composition and the presence/absence of dissolved CO₂)was performedusing the four most commonly consumed bottled water brands on the Chilean market. Each water brand was analyzed between 10 or 14 different times, depending on the brand (in total 97 samples were studied). Following the concept ofthe hydrochemical signature typically used in hydrogeology to classify types of waters, the notion of a water phthalate fingerprint was proposed. Finally, concerning the effect of long storage times, this study demonstrates that all the trends (increase, decrease or steady) of the Total PAEs concentration are possible; and these trends are controlled by the specific hydrochemical signatureandphthalate fingerprint of the bottled water.

Recent Advances in Solid-Phase Extraction as a Platform for Sample Preparation in Biomarker Assay

Low levels of biomarkers and the complexity of bio sample make the analytical assay of several biomarkers a challenging issue. Suitable sample preparation run remain a vital part of the puzzle of diagnostic level. Enhancing the detection limit of bioanalytical methods start during the sample preparation procedure. A robust sample preparation method is needed to evaluate the number of biomarkers. As worldwide environmental issues attract expanding consideration, all the more harmless to the ecosystem investigations are liked. Solid-phase extraction (SPE) is an appealing strategy among the sample treatment methods due to the versatility of sorbent materials, less solvent consumption, and compatibility with analytical devices. Miniaturization of the SPE gives the chance to integrate the other analytical steps in a single run, known as an easy-to-use and effective method. SPE utilizes various SPE sorbent beds such as packed beads, porous polymer monoliths, molecularly imprinted polymers, membranes, or other magnetic form microstructures to achieve high surface-to-volume ratio and appropriate chemical properties effective extraction. Also, SPE is the methodology of interest to fulfill high recovery and efficiency demands. In this review, we intend to explain more recent methods for the rational design of SPE and miniaturized SPE to determine biomarkers from biological media. The headlines are subdivided into (1) packing materials in SPE, (2) setups for sample preparation by magnetic SPE, and (3) and future perspective for the application of SPE in sample preparation for analysis of biomarkers.

Method development using chemometric tools for determination of endocrine-disrupting chemicals in bottled mineral waters

A simple method was developed to determine 14 endocrine-disrupting chemicals (EDCs) in bottled waters, based on dispersive micro-solid phase extraction (d-µ-SPE) and liquid chromatography-mass spectrometry (LC-MS). Extraction was optimized using 2 ^k-1 factorial and Doehlert experimental designs. Optimized conditions were 80 mg C18, 25 min extraction at 1000 rpm, and 6 min desorption time. Repeatability was below 17 % for all EDCs. LOD and LOQ varied from 1.60 ng L^-1 (estradiol, E2) to 23.2 ng L^-1 (dimethylphthalate, DMP) and from 5.33 ng L^-1 (E2) to 77.3 ng L^-1 (DMP). We found DMP and bisphenol A (BPA) in samples after the heat treatment. DMP was up to 58.7 µg L^-1, while BPA was up to 1.34 µg L^-1. Tolerance of daily intake (TDI) for DMP were 2.50-2.94 µg kg^-1 day^-1 (children) and 1.43-1.68 µg kg^-1 day^-1 (adults). TDI for BPA were 0.03-0.07 µg kg^-1 day^-1 (children) and 0.01-0.04 µg kg^-1 day^-1 (adults).

Determination of Deoxynivalenol and Its Derivative in Corn Flour and Wheat Flour Using Automated On-line Solid-Phase Extraction Combined with LC-MS/MS

An automated on-line solid-phase extraction (SPE) combined with LC-MS/MS method was developed for determination of deoxynivalenol (DON), 3-acetyl-DON and 15-acetyl-DON in corn flour and wheat flour samples. The extraction solvent of the samples was injected into the automated on-line SPE system to remove matrix interference. After washing step, the targets were eluted from the SPE cartridge into liquid chromatography (LC) column. Several SPE parameters including injection volume, elution volume and eluting flow rate were assessed and optimized. Method validation was evaluated and good linearity was obtained (R² > 99%) with the limit of detection of 0.1-0.2 μg/kg. Recoveries were evaluated in spiked corn flour and wheat flour samples at three concentrations and the values ranged from 86.5% to 99.7%. The benefit of the present method with automated on-line SPE system is the ability to inject directly pure extracts into LC-MS/MS, offering faster analyses and improving analysis efficiency.

Occurrence and removal characteristics of phthalate esters from bottled drinking water using silver modified roasted date pits

BACKGROUND

This paper aims to investigate the occurrence and removal characteristics of phthalate esters from bottled drinking water using silver modified roasted date pits. Three adsorbents, namely roasted date pits (RODP), silver-modified roasted date pits (S-RODP), and activated carbon (AC) were used to investigate their adsorption characterizations in removing dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), di-2-ethylhexyl phthalate (DEHP), and di-n-octyl phthalate (DNOP) from the collected bottle water samples.

METHODS

The occurrences of the phthalate esters in the collected bottled water samples were carried out at different temperatures (30, 50, and 60 °C), and analyzed using gas chromatography-mass spectrometry analysis - selected ion monitoring. Batch adsorption isotherms were used to study and establish the efficiency of such adsorbents in removing phthalate esters, in which they describe the adsorbent-adsorbate interaction systems. Adsorption efficiency of the various adsorbents was investigated by using different adsorbent masses (0.05 g, 0.10 g, and 0.15 g) and temperature (30 °C, 50 °C, and 60 °C). Different physical and chemical characterizations were studied using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Brunauer-Emmett-Teller (BET) surface area, pore radius, and pore volume.

RESULTS

The results indicated that the most abundant phthalate esters were DMP followed by DEP under 30 °C; however, DNOP was not detected in any of the tested water samples, except for one sample under 30 °C with a concentration of 0.031 μg/mL. The obtained results showed that phthalate esters leaching to the bottled drinking water were affected by storage temperature. The phthalate esters levels were increased with increasing the temperature to 60 °C. It was concluded that the ability of S-RODP for the adsorption of phthalate esters was better than the removal percentage obtained by AC and RODP. The removal percentage was increased from 90 to 99% by increasing the temperature from 30 to 50 °C and then decreased to 92.3% at 60 °C.

CONCLUSION

RODP was successfully used as an effective adsorbent for phthalate esters removal from drinking water. However, S-RODP has the highest removal abilities than other adsorbents due to the newly formed functional groups on its surface.

Potential risk of BPA and phthalates in commercial water bottles: a minireview

The global water bottling market grows annually. Today, to ensure consumer safety, it is important to verify the possible migration of compounds from bottles into the water contained in them. Potential health risks due to the prevalence of bisphenol A (BPA) and phthalates (PAEs) exposure through water bottle consumption have become an important issue. BPA, benzyl butyl phthalate (BBP), di-n-butyl phthalate (DBP) and di (2-ethylhexyl) phthalate (DEHP) can cause adverse effects on human health. Papers of literature published in English, with BPA, BBP, DBP and DEHP detections during 2017, by 2019 by liquid chromatography and gas chromatography analysis methods were searched. The highest concentrations of BPA, BBP, DBP and DEHP in all the bottled waters studied were found to be 5.7, 12.11, 82.8 and 64.0 μg/L, respectively. DBP was the most compound detected and the main contributor by bottled water consumption with 23.7% of the Tolerable Daily Intake (TDI). Based on the risk assessment, BPA, BBP, DBP and DEHP in commercial water bottles do not pose a serious concern for humans. The average estrogen equivalent level revealed that BPA, BBP, DBP and DEHP in bottled waters may induce adverse estrogenic effects on human health.

Occurrence, migration and health risk of phthalates in tap water, barreled water and bottled water in Tianjin, China

This study was to investigate the occurrence, migration and health risk of phthalic acid esters (PAEs) in tap water, barreled water and bottled water in Tianjin, China. Six priority controlled PAEs were measured, among which the detection frequency of butyl benzyl phthalate (BBP), dibutyl phthalate (DBP) and di(2-ethylhexyl) phthalate (DEHP) was 100%, while the others were not detected. The concentration of DEHP was higher than BBP and DBP in all the samples. The initial ∑₃PAEs concentrations in tap water, barreled water and bottled water were 2.409 ± 0.391 μg/L, 1.495 ± 0.213 μg/L and 1.963 ± 0.160 μg/L, respectively. Boiling tap water could reduce the PAEs content to an extent, but they increased significantly in hot tap water contacting with disposable plastic cups. The migration of PAEs in barreled water and bottled water were positively correlated with storage time and temperature, which could be described by exponential models. The hazard indexes of PAEs in different types of drinking water were very low. However, the human carcinogenic risks of DEHP will reach the maximum acceptable risk level of 10^-6 when bottled water is stored for 8.8 days at 40 °C, 7.7 days at 50 °C, or 6.1 days at 60 °C.

Novel strategy for disposable pipette extraction (DPX): Low-cost Parallel-DPX for determination of phthalate migration from common plastic materials to saliva simulant with GC-MS

In widespread use in commercial products as plasticizers, phthalic acid esters (phthalates) have worried researchers and society in general, given the negative impacts on living organisms, especially human health. Since they are not chemically linked to the polymeric matrix, their migration is evident for samples that come into contact with plastics that contain them, such as water, food and saliva. In this work, a new strategy is described, named parallel-disposable pipette extraction (Pa-DPX), in a fast, efficient and robust analytical method using five simultaneous extractions for the determination of migration of 6 phthalates from common plastic materials (children's toys, school supplies, dog toys and oral contact items) to saliva simulant, using gas chromatography-mass spectrometry (GC-MS). The optimized conditions were 5 extraction cycles with 1600 μL of saliva simulant and desorption with 200 μL of ethyl acetate using 5 cycles with the same aliquot. The calibration curves resulted in determination coefficients higher than 0.9915, limits of detection at 1.5 μg L^-1, and the quantification limits were 5.0 μg L^-1. Excellent results were obtained for repeatability (relative standard deviation ranging from 8.7% to 20.1% for 5 μg L^-1) and intermediate precision, varying the day of analyses (7.9%-16.2%). The analyte recovery ranged from 75% to 114% for two different samples, in four different levels of concentration. The Pa-DPX-GC-MS method was successfully applied to determine the migration of PAE from 21 samples. At least one PAE was detected in 81% of samples, and di-n-octyl phthalate was found in higher concentration, achieving the migration of almost 30 μg per g of sample.

Preparation of magnetic zeolitic imidazolate framework-67 composites for the extraction of phthalate esters from environmental water samples

In this paper, magnetic ZIF-67 composites were prepared by an in situ method and utilized in the magnetic solid-phase extraction of phthalate esters. The obtained magnetic ZIF-67 composites were characterized in detail, and the adsorption performance was evaluated. The results showed that ZIF-67 crystals in the composites had a chamfered cubic shape with about 2.0 μm diameter and Fe3O4 was attached on the surface of ZIF-67. The parameters affecting magnetic solid-phase extraction efficiency were optimized including the adsorption and desorption conditions. Under the optimum conditions, magnetic solid-phase extraction coupled with gas chromatography-mass spectrometry for analyzing seven phthalate esters in environmental water samples was established. All the analytes exhibited good linearity (1-200 ng mL-1) with correlation coefficients higher than 0.9950. The relative standard deviations were between 4.3% and 8.9%. The developed method showed high sensitivity and had good potential for analyzing trace phthalate esters in water samples.

Development of a sensitive method for the analysis of four phthalates in tea samples: Tea bag contribution to the total amount in tea infusion

A sensitive, precise and selective method for the analysis of butyl benzyl phthalate (BBP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and dimethyl phthalate (DMP) in tea samples has been applied. Molecularly Imprinted Polymer-Solid Phase Extraction (MIP-SPE) has been used for the separation and preconcentration of these compounds. Phthalates extracted by SPE were analysed by high-performance liquid chromatography-electrospray ionisation-mass spectrometry (HPLC-ESI-MS). The method was sensitive (LOD < 2 µg L^-1), precise (RSD <10%) and accurate with recovery percentages ranging from 84% to 97%. Finally, the developed method was applied for the analysis of these phthalates in several tea samples marketed in bags. Migration studies were also performed to evaluate the concentration of phthalates released from the bags into the infusions, and teabag filters were analysed by Fourier-transform infrared spectroscopy. The migration study shows that tea filter bags contribute to the total phthalates concentration in tea infusion, and this contribution varies between 1.8 to 93.5 % of the total phthalates' concentrations. Tea filter bags release higher DBP than BBP, DMP, and DEP.

Worldwide bottled water occurrence of emerging contaminants: A review of the recent scientific literature

Contaminants of emerging concern (CECs) have recently been detected in bottled water and have brought about discussions on possible risks for human health. However, a systematic review of CECs in bottled water is currently lacking due to the relatively new introduction and/or detection of these pollutants. Hence, this paper reviews the existing studies on the presence of six major groups of emerging contaminants including microplastics (MPs), pharmaceuticals and personal care products (PPCPs), bisphenol A (BPA), phthalates, alkylphenols (APs), and perfluoroalkyl and polyfluoroalkyl substances (PFASs) in bottled water from different countries. Also, the findings related to CECs' levels, their possible sources, and their risks are summarized. The gathered data indicate that MPs within the size range of 1-5 μm are the most predominant and potentially toxic classes of MPs in bottled water. In addition, PPCPs, PFASs, APs, and BPA occur in concentration levels of ng/L, while phthalates occur in the μg/L level in bottled water. The bottle type plays an important role in the contamination level. As expected, water in plastic bottles with plastic caps is more polluted than in glass bottles. However, other sources of contamination such as contact materials during cleaning, bottling, and storage are not negligible. Based on the gathered data in this review, the CEC levels except for MPs (no threshold values) in bottled water of most countries do not raise a safety concern for the human. However, the occurrence of individual CECs and their association in bottled water need more accurate data to understand their own/synergistic effects on human health.

Online coupling of the Ussing chamber, solid-phase extraction and high-performance liquid chromatography for screening and analysis of active constituents of traditional Chinese medicines

A semi-automated online platform was established successfully for preliminary screening of potential active flavonoids of traditional Chinese medicines (TCMs) in multicomponent system. Online coupling of the in vitro intestinal absorption model, solid phase extraction (SPE) and high-performance liquid chromatography (HPLC) was actualized at the first time. The Ussing chamber model was selected to absorb the constituents of TCMs. A mini chromatographic column filled with C18 was used as a SPE column for online enrichment of flavonoids. HPLC was applied to analyze the constituents screened by platform. With the use of rutin as a model flavonoid, the specifications of SPE column, eluting solvent, elution time and flow rate of eluent were systematically investigated to optimize online system. Under the optimal conditions, the linear range of rutin was 0.125-368 µg/mL with the correlation coefficient (R²) greater than 0.9947. The limit of detection (LOD) was as low as 0.0500 µg/mL and the limit of quantification (LOQ) was 0.125 µg/mL. The intra-day relative standard deviation (RSD) and inter-day RSD was 2.5% and 3.8%, respectively. The recoveries of rutin in the intestinal absorption samples ranged from 93.2% to 94.0%. Finally, the online system was applied to screen the potential active flavonoids of Scutellaria baicalensis Georgi (Huangqin, HQ) and Polygoni Cuspidati Rhizoma et Radix (Huzhang, HZ). A total of 14 flavonoids of these two TCMs were identified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and 12 flavonoids of them were screened as the potential active components by online Ussing chamber-SPE-HPLC. In comparison with offline method and gavage in rats, the online system can screen the active constituents from TCMs more accurately and completely. The results demonstrated that the online system was reliable and sufficiently accurate for screening and determination of the potential active flavonoids of TCMs in multicomponent system.

A miniature stainless steel net dumbbell-shaped stir-bar for the extraction of phthalate esters in instant noodle and rice soup samples

This work reports the development of a very-simple-to-construct stir-bar extraction device so called "a dumbbell-shaped stainless steel stir-bar." The extraction device was assembled from a rolled up stainless steel net filled with an XAD-2 sorbent and a metal rod to allow the use of a magnetic stirrer during extraction. The dumbbell-shaped stainless steel stir-bar was used to extract diethyl phthalate (DEP), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP) before analysis by a gas chromatograph equipped with an electron capture detector (GD-ECD). Under the optimal conditions, the developed method provided a good linearity from 10.0 to 1,000.0 ng mL^-1 for all three compounds. Limits of detection and limits of quantification were 9.37 ± 0.29 ng mL^-1 and 31.22 ± 0.95 ng mL^-1 for DEP, 5.73 ± 0.31 ng mL^-1 and 19.1 ± 1.0 ng mL^-1 for DBP and 3.30 ± 0.06 ng mL^-1 and 11.0 ± 0.19 ng mL^-1 for DEHP, respectively. Good recoveries in the range of 81.89 ± 0.17 to 109.5 ± 2.0% were achieved when the method was used to extract phthalate esters in five instant noodle and two rice soup samples.

A novel aptamer-based online magnetic solid phase extraction method for simultaneous determination of urinary 8-hydroxy-2'-deoxyguanosine and monohydroxylated polycyclic aromatic hydrocarbons

In this work, an innovative aptamer-based magnetic adsorbent (Fe₃O₄@PDA-aptamer MNPs) was prepared by hydrothermal synthesis method followed by the surface functionalization of nanoparticles. After fixing in a steel stainless tube as sorbent of magnetic solid phase extraction (MSPE), an online magnetic solid phase extraction-high performance liquid chromatography-mass spectrometry (online-MSPE-HPLC-MS) method was developed and applied for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) simultaneously in urine. The synthesized sorbent presented outstanding features, including large specific surface area, high enrichment capacity and excellent stability. High throughput analysis can be achieved by affinity-specific adsorption of 8-OHdG and non-specific adsorption of OH-PAHs at the same time. In addition, online MSPE can greatly simplify the analysis process, reduce human errors and enhance the sensitivity. When compared with offline MSPE, a sensitivity enhancement of 30-400 times was obtained for the online method. Some experimental parameters such as the amount of the sorbent, sampling flow rate and sample volume, were optimized systematically. Under the optimal conditions, the limits of detection (LOD) were in the range of 0.028-0.114 ng mL^-1, and the correlation coefficients (R²) were higher than 0.9962. The relative standard deviations (RSDs) were less than 16.1% (n = 5) and the recoveries ranged from 71% to 116%. The above results show that the rapid, sensitive and automated online-MSPE-HPLC-MS method has potential application in the simultaneous determination of 8-OHdG and PAHs in complex sample matrix to assess the environmental exposure level.

Current Trends in Fully Automated On-Line Analytical Techniques for Beverage Analysis

The determination of target analytes in complex matrices such as beverages requires a series of analytical steps to obtain a reliable analysis. This critical review presents the current trends in sample preparation techniques based on solid phase extraction miniaturization, automation and on-line coupling. Techniques discussed include solid-phase extraction (SPE), solid-phase microextraction (SPME), in-tube solid-phase microextraction (in-tube SPME) and turbulent-flow chromatography (TFC). Advantages and limitations, as well as several of their main applications in beverage samples are discussed. Finally, fully automated on-line systems that involve extraction, chromatographic separation, and tandem mass spectrometry in one-step are introduced and critically reviewed.

Migration and potential risk of trace phthalates in bottled water: A global situation

Increasing attention has been dedicated to trace phthalates in bottled water due to the serious concerns on public health, while there is still a lack of systematic analysis and assessment of current global situation. Through analyzing five representative phthalates in bottled water over 20 countries, this work clearly revealed the phthalates-associated potential risks in both human daily intake and estrogenic effect. In the risk assessment, the kinetic models were also developed to describe and predict phthalates migration. In more than three hundred brands of bottled waters from twenty one countries, the detection frequency of the five targeted phthalates was found to be in the order of dibutyl phthalate (DBP, 67.6%), di-2-(ethyl hexyl) phthalate (DEHP, 61.7%), diethyl phthalate (DEP, 47.1%), benzyl butyl phthalate (BBP, 36.9%), and dimethyl phthalate (DMP, 30.1%). Among the countries studied relating concentrations of DEHP in bottled waters, the top five countries ranked in the order of high to low were Thailand, Croatia, Czech Republic, Saudi Arabia and China with an average level of 61.1, 8.8, 6.3, 6.2 and 6.1 μg/L, respectively. The average levels of BBP, DBP, DMP and DEP in bottled water from Pakistan were high, in which DEP and DMP were ranked 1st among all countries with the average levels of 22.4 and 50.2 μg/L, while BBP and DBP were ranked 2nd and 3rd with the average levels of 7.5 and 17.8 μg/L, respectively. The human daily intake-based risk assessment revealed that phthalates in bottled waters studied would not pose a serious concern on public health. However, the adverse estrogenic effects of phthalates in bottled water from some countries appeared to be significant. This study just shed light on global situation of phthalates in bottled water, and more efforts should be needed to systematically examine the phthalates-related safety of bottled water.

A novel aptamer-based online magnetic solid phase extraction method for the selective determination of 8-hydroxy-2'-deoxyguanosine in human urine

In this work, an innovative magnetic aptamer adsorbent (Fe₃O₄-aptamer MNPs) was synthesized for the selective extraction of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Amino-functionalized-Fe₃O₄ was crosslinked with 8-OHdG aptamer by glutaraldehyde and fixed into a steel stainless tube as the sorbent of magnetic solid phase extraction (MSPE). After selective extraction by the aptamer adsorbent, the adsorbed 8-OHdG was desorbed dynamically and online analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). The synthesized sorbent presented outstanding features, including specific selectivity, high enrichment capacity, stability and biocompatibility. Moreover, this proposed MSPE-HPLC-MS can achieve adsorption and desorption operation integration, greatly simplify the analysis process and reduce human errors. When compared with offline MSPE, a sensitivity enhancement of 800 times was obtained for the online method. Some experimental parameters such as the amount of the sorbent, sample flow rate and sample volume, were optimized systematically. Under the optimal conditions, low limit of detection (0.01 ng mL^-1, S/N = 3), limit of quantity (0.03 ng mL^-1, S/N = 10) and wide linear range with a satisfactory correlation coefficient (R² ≥ 0.9992) were obtained. And the recoveries of 8-OHdG in the urine samples varied from 82% to 116%. All these results revealed that the method is simple, rapid, selective, sensitive and automated, and it could be expected to become a potential approach for the selective determination of trace 8-OHdG in complex urinary samples.