Phthalates in Beverages and Plastic Bottles: Sample Preparation and Determination

Innovative extraction methods for non-phthalate plastic additives determination in water using GC and LC coupled to Q-Orbitrap

This study investigates the presence of non-phthalate plastic additives (NPPAs), emerging contaminants increasingly used as alternatives to hazardous phthalates, in various water sources. To address their potential environmental and health risks, two complementary extraction methods were developed: direct immersion solid-phase microextraction gas chromatography coupled to Q-Orbitrap (DI-SPME-GC-Q-Orbitrap) and salting-out assisted liquid-liquid extraction combined with ultra-high-performance liquid chromatography (SALLE-UHPLC-Q-Orbitrap). The complementary use of these two methods makes it possible to analyse a larger number of analytes, 27 in particular, enabling the detection of 19 and 23 NPPAs by GC and LC, respectively (15 compounds were simultaneously monitored by both techniques), with limits of quantification (LOQs) ranging from 0.05 to 4.0 μg/L. Both methods demonstrated satisfactory trueness and precision in accordance with analytical validation standards. The application of these methods to water samples revealed the widespread presence of NPPAs, particularly 1-hydroxycyclohexyl phenyl ketone (HCPK) and triacetin (TA), which were detected at concentrations up to 5.33 μg/L. Toxicity assessments based on LD50 values indicated that these compounds pose significant environmental and health risks, surpassing some restricted phthalates in toxicity. These findings underscore the urgent need to monitor and regulate NPPAs as hazardous materials to safeguard water quality and public health. This work highlights the utility of green analytical methods for evaluating emerging pollutants in water systems, aligning with the principles of sustainable environmental management.

Fate and ecological risk assessment of phthalates in wastewater treatment plants

With the rapid increase in plastics use worldwide, phthalates (PAEs) as an endocrine disruptor, have been receiving attention. It is necessary to investigate the pivotal considerations affecting the degradation of PAEs and the ecological risk assessment in wastewater treatment plants. The presence and spatial distribution patterns of 16 PAEs across three wastewater treatment plants (WWTPs) in northern China were studied by collecting wastewater samples, and by comparing the mechanism of action of AAO and oxidation ditch process on the removal efficiency of long and short chain PAEs, we fill the gap in the study of comprehensive assessment and process-specific removal effect of multiple PAEs. The influent concentration of PAEs and the treatment process were the pivotal considerations in the primary and secondary treatments, respectively. In the primary treatment stage, long-chain PAEs were more readily removed compared to short-chain PAEs. Conversely, during the secondary treatment, short-chain PAEs were removed more effectively than long-chain PAEs, independent of the specific treatment process. Long-chain PAEs were more easily removed during the AAO processes. Furthermore, the ecological risk assessment of the effluent was conducted at each stage of the three WWTPs. The ecological risk assessment results of the three WWTPs for fish and Daphnia showed no risk, while that for green algae showed a low risk. These findings can be used as a model for controlling PAEs and provide important information on the occurrence and distribution of PAEs in WWTP and their ecological risks of effluents.

Improving the reliability of phthalate esters analysis in water samples by gas chromatography-tube plasma ionization-high-resolution mass spectrometry (GC-TPI-HRMS)

The monitoring of phthalate esters (PAEs) is challenging due to background contamination as well as the low selectivity observed when analyzing them by gas chromatography coupled to mass spectrometry (GC-MS) using electron ionization (EI). In this sense, alternative and soft ionization techniques could help to enhance the performance of the analytical determinations of PAEs in food samples. In this work, the use of a novel and soft ionization technique tube plasma ionization (TPI) has been explored to enhance the selectivity and sensitivity in the determination of PAEs in drinking water samples with GC-MS. First, the ionization behavior of PAEs by TPI is evaluated showing the generation of an abundant protonated molecule. Source and plasma related parameters were carefully optimized to increase the ionization efficiency and ion transmission, showing that the fragmentor voltage is a key parameter to avoid in-source fragmentation. Moreover, the use of additives and different electrode materials is also tested to enhance the ionization efficiency and to better understand TPI mechanisms. Tungsten-made electrode with no additives showed the highest performance and better robustness for long-term operation. The proposed methodology using GC-TPI-MS was instrumentally compared with other atmospheric pressure ionization sources showing significantly lower limits of detection for the TPI source compared to atmospheric pressure ionization techniques (up to 700 times). Moreover, TPI also demonstrates comparable figures of merit in regard to the gold-standard ionization technique (EI). The combination of the GC-TPI-HRMS method together with a headspace-solid phase microextraction (HS-SPME) allows the detection of PAEs in drinking water up to 1 ng L-1 with precision (RSD <23 %) and trueness (Rel. Error <20 %). The method is then applied to quantify PAEs in drinking water and carry out migration studies from different polyethylene terephthalate-based bottle under stress situation, showing the high versatility of TPI to face complex analytical determinations such as PAEs analysis.

Recent advancements in the extraction and analysis of phthalate acid esters in food samples

Phthalate acid esters (PAEs) are ubiquitous environmental pollutants present in food samples, necessitating accurate detection for risk assessment and remediation efforts. This review provides an updated overview of the recent progress on the PAEs analysis regarding sample pretreatment techniques and analytical methodologies over the latest decade. Advances in sample preparation include solid-based extraction techniques replacing conventional liquid-liquid extraction, with solid sorbents emerging as promising alternatives due to their minimal solvent consumption and enhanced selectivity. Although techniques like the microextraction methods offer versatility and reduced solvent reliance, there is a need for more efficient and environmentally friendly techniques enabling on-site portable detection. High-resolution mass spectrometry is increasingly utilized for its enhanced sensitivity and reduced contamination risks. However, challenges persist in developing in situ analytical techniques for trace PAEs in complex food samples. Future research should prioritize novel analytical techniques with superior sensitivity and selectivity, addressing current limitations to meet the demand for precise PAEs detection in diverse food matrices.

Analysis and remediation of phthalates in aquatic matrices: current perspectives

Phthalic acid esters (PAEs) are high production volume chemicals used extensively as plasticizers, to increase the flexibility of the main polymer. They are reported to leach into their surroundings from plastic products and are now a ubiquitous environmental contaminant. Phthalate levels have been determined in several environmental matrices, especially in water. These levels serve as an indicator of plasticizer abuse and plastic pollution, and also serve as a route of exposure to different species including humans. Reports published on effects of different PAEs on experimental models demonstrate their carcinogenic, teratogenic, reproductive, and endocrine disruptive effects. Therefore, regular monitoring and remediation of environmental water samples is essential to ascertain their hazard quotient and daily exposure levels. This review summarises the extraction and detection techniques available for phthalate analysis in water samples such as chromatography, biosensors, immunoassays, and spectroscopy. Current remediation strategies for phthalate removal such as adsorption, advanced oxidation, and microbial degradation have also been highlighted.

Preparation of SERS substrate with 2D silver plate and nano silver sol for plasticizer detection in edible oil

As a widely used industrial additive of plastic products, phthalate ester (PAE) plasticizers can easily migrate into food, threatening human health. In this work, we proposed a rapid, precise, and reliable method to detect PAE plasticizers in edible oils by using surface-enhanced Raman spectroscopy (SERS) technology. A two-dimensional (2D) silver plate synergizing with a nanosilver sol was prepared as a substrate for SERS to detect potassium hydrogen phthalate (PHP), a hydrolysate of a PAE plasticizer. Detection conditions, such as pH values, drying times, and hydrolysate interference, were optimized. The working curve was well fitted with a linear parameter R² of 0.9994, and the minimum detection limit was evaluated as 10^-9 mol/L. Furthermore, the detection accuracy was supported by five edible oil samples. Therefore, using SERS technology to detect PHP is expected to provide an avenue for PAE plasticizer detection in oils and fats, and it features promising potential applications in food safety.

The fate of phthalate acid esters in wastewater treatment plants and their impact on receiving waters

Phthalates (PAEs) are gaining attention and being researched as an endocrine disruptor as global plastic use surge. There is an urgent need to explore the key factors affecting the removal of PAEs from wastewater and the impact of wastewater effluent on receiving water. Here we investigated the levels and distribution patterns of 16 typical PAEs in surface water and five wastewater treatment plants (WWTPs) along the Dongyang River from Yiwu, China, collecting 42 surface water and 31 wastewater samples. We found that influent PAEs concentration and treatment process were the key factors affecting the degradation efficiency of PAEs in primary and secondary treatment, respectively. In primary treatment, long-chain PAEs were more easily removed (and sometimes less likely to accumulate) than short-chain PAEs, regardless of the influent PAEs concentration (a key factor in primary treatment), while in secondary treatment, short-chain PAEs were easily removed regardless of the treatment process (a factor in secondary treatment). This was not the case for long-chain PAEs, which were only more readily removed in the A/A/O process. In addition, by comparing the significant differences between wastewater and surface water, we found that the total PAEs in the treated effluent were significantly lower than in surface water upstream and in built-up urban areas, indicating that wastewater discharges in the study area did not increase PAEs in the receiving water. Finally, river in the city center and artificial treatment facilities in the study area were identified as requiring priority attention. The results of this study can serve as a model for controlling PAEs in other similar developing cities in China and provide valuable information on the fate of endocrine disruptor from wastewater treatment in China and their impact on surface water.

Monitoring of the presence of plasticizers and effect of temperature and storage time in bottled water using a green liquid-liquid microextraction method

In this work, a natural deep eutectic solvent was used for the liquid-liquid microextraction of fourteen phthalates and one adipate from bottled waters. The methodology was validated in terms of matrix effect, linearity, recovery, and limits of quantification (LOQs). Optimum extraction conditions (10 mL of water at pH 8.0 with 100 μL of thymol: menthol 2:1 (n/n) as solvent) provided satisfactory determination coefficients (≥ 0.9977), recovery values (82-127%), and LOQs (0.018-0.523 μg/L). The effects of temperature and storage time on plasticizer presence were studied for 36 different brands stored at 4 °C, room temperature, and 45 °C, and analyzed at 0, 24, 48, 72 h, and 1 week. Only diethyl-, dibutyl-, bis-(2-ethylhexyl) phthalates, and bis-(2-ethylhexyl) adipate were detected. The results showed that there is no relationship between the storage conditions, the bottle material or water carbonation, and the occurrence of these plasticizers, suggesting that residues are introduced during production or by the water supply. The estimated daily intake was lower than the total daily intake set by the European Food Safety Authority.

Development of Lateral Flow Test-System for the Immunoassay of Dibutyl Phthalate in Natural Waters

The use of a large amount of toxic synthetic materials leads to an increase in the pollution of environmental objects. Phthalates are compounds structurally related to esters of phthalic acid that are widely used in the manufacturing of synthetic packaging materials as plasticizers. Their danger is conditioned by leaching into the environment and penetrating into living organisms with negative consequences and effects on various organs and tissues. This work presents the first development of lateral flow immunoassay to detect dibutyl phthalate, one of the most common representatives of the phthalates group. To form a test zone, a hapten-protein conjugate was synthesized, and gold nanoparticles conjugated with antibodies to dibutyl phthalate were used as a detecting conjugate. The work includes the preparation of immunoreagents, selectivity investigation, and the study of the characteristics of the medium providing a reliable optical signal. Under the selected conditions for the analysis, the detection limit was 33.4 ng/mL, and the working range of the determined concentrations was from 42.4 to 1500 ng/mL. Time of the assay-15 min. The developed technique was successfully applied to detect dibutyl phthalate in natural waters with recovery rates from 75 to 115%.

Determination of phthalates in bottled waters using solid-phase microextraction and gas chromatography tandem mass spectrometry

Phthalates are synthetic chemicals widely used, mainly as plasticizers, which are ubiquitous and recognized as endocrine-disrupting chemicals. For investigation of phthalate residues leached from PET bottles into drinking water, a simple and sensitive method was developed, validated and applied to a series of real samples. Solid-phase microextraction (SPME) was used in direct immersion mode for concentration of phthalate traces from 10 mL of each water sample. Four commercially available SPME fibers were tested and compared, while six dialkyl phthalates were investigated: dimethyl phthalate (DMP), diethyl phthalate (DEP), diisopropyl phthalate (DiPP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP) and di-ethylhexyl phthalate (DEHP). The extracted phthalic acid esters were separated and quantified by gas chromatography hyphenated with tandem mass spectrometry (GC-MS/MS) and a detection method based on multiple reaction monitoring (MRM) mode was fully developed, optimized and validated. The fiber which showed the highest ability for extraction of phthalates was DVB/CAR/PDMS which combines a liquid polymeric coating (polydimethyl siloxane and divinylbenzene) with a carboxen porous sorbent layer. The obtained limit of detection was in the range between 0.3 and 2.6 ng mL^-1. Thus, this fiber was used for extraction of phthalates from twelve commercial PET bottled water samples. All investigated water brands showed the presence of two to six phthalates at concentrations between 6.3 and 112.2 ng mL^-1. The highest level was observed for DnBP, followed by DEHP, DiBP, DMP, DEP and DiPP.

Determination of Five Phthalate Esters in Tea and Their Dynamic Characteristics during Black Tea Processing

A highly specific and high extraction-rate method for the analysis of dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), diisobutyl phthalate (DiBP), and di-(2-ethyl) hexyl phthalate (DEHP) in tea samples was developed. Based on three-factor Box-Behnken response surface design, solid-phase extraction (SPE) of five phthalate ester (PAE) residues in tea was optimized. Optimal extraction conditions were found for extraction temperature (40 °C), extraction time (12 h), and ratio of tea to n-hexane (1:20). The dynamic distribution of PAEs at each stage of black tea processing was also analyzed, and it was found that the baking process was the main stage of PAE emission, indicating that traditional processing of black tea significantly degrades PAEs. Further, principal component analysis of the physicochemical properties and processing factors of the five PAEs identified the main processing stages affecting the release of PAEs, and it was found that the degradation of PAEs during black tea processing is also related to its own physicochemical properties, especially the octanol-water partition coefficient. These results can provide important references for the detection, determination of processing losses, and control of maximum residue limits (MRLs) of PAEs to ensure the quality and safety of black tea.

Amphiphilic BODIPY-based nanoparticles as "light-up" fluorescent probe for PAEs detection by an aggregation/disaggregation approach

Phthalic acid eaters (PAEs) play the role of plasticizer and have been widely used in the industrial and plastic production process. But due to not chemically bound in the polymeric matrix, PAEs can be easily released directly and/or indirectly into the environment, and pose a threat the ecosystem and human health. Small-molecule self-assembled nanoparticles have drawn more and more attention due to advantages of precise molecular structure, biocompatibility, great diversity, and tunability in optical properties and functionalities. Here we report the use of disaggregation-induced emission (DIE) based supramolecular assembly to design organic nanoprobe for detection PAEs. In the water solution, the designed small organic fluorophore AJ-1 was aggregated via noncovalent forces to form fluorescence off nanoparticles, but in the presence of PAEs, they disaggregated and produced a clear light-up fluorescent signal. The detection of PAEs with selectivity, sensitivity and rapid response were further achieved. The experiment of recovery of PAEs in real-water sample illustrated the practicability of probe AJ-1 in real-world applications. Besides, cellular uptake assay suggested that AJ-1 could pass through membrane and gather in the cytoplasm.

Evaluation of the Occurrence of Phthalates in Plastic Materials Used in Food Packaging

Phthalates are multifunctional synthetic chemicals found in a wide array of consumer and industrial products, mainly used to improve the mechanical properties of plastics, giving them flexibility and softness. In the European Union, phthalates are prohibited at levels greater than 0.1% by weight in most food packaging. In the current study, headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was optimized, through the multivariate optimization process, and validated to evaluate the occurrence of four common phthalates, di-iso-butyl phthalate (DIBP), butyl-benzyl phthalate (BBP), di-n-octyl phthalate (DOP), and 2,2,4,4-tetrabromodiphenyl (BDE), in different food packaging. The best extraction efficiency was achieved using the polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber at 80 °C for 30 min. The validated method showed good linearity, precision (RSD < 13%), and recoveries (90.2 to 111%). The limit of detection (LOD) and of quantification (LOQ) ranged from 0.03 to 0.08 µg/L and from 0.10 to 0.24 µg/L, respectively. On average, the phthalates concentration varied largely among the assayed food packaging. DIBP was the most predominant phthalate in terms of occurrence (71.4% of analyzed simples) and concentration (from 3.61 to 10.7 μg/L). BBP was quantified in only one sample and BDE was detected in trace amounts (<LOQ) in only two samples.

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.

Targeted and untargeted gas chromatography-mass spectrometry analysis of honey samples for determination of migrants from plastic packages

Plastic food packages usually contain additives which may migrate from the package into the food and then be ingested by the consumer, representing a risk for their health. In this study, targeted and untargeted analysis by gas chromatography-mass spectrometry (GC-MS) is proposed to monitor any contaminants of this type in honey. The application of dispersive liquid-liquid microextraction (DLLME) as a preconcentration technique allowed very low detection limits to be reached for all the substances. Fifteen target compounds, including styrene, phthalates, fatty acids, alkylphenols and bisphenol A, were quantified. Untargeted analyses were also carried out, allowing other migrants in the honey samples to be identified, such as two phthalates, four acids, three esters, one aldehyde, one hydrocarbon and two alkyl phenol compounds. The proposed method was seen to be a useful approach for the quantification and identification of potential migrants from plastics in challenging samples such as honey.

Enrichment-Free Rapid Detection of Phthalates in Chinese Liquor with Electrochemical Impedance Spectroscopy

A non-invasive real-time detection technique for phthalates in Chinese liquor is proposed in this paper. This method is based on the measurement of Faradaic impedance in the presence of a redox probe, [Fe(CN)₆]^3−/4−, upon the absorption of phthalates to the graphene electrode surface. This absorption activity is according to the π–π stacking interactions between phthalates and the graphene working electrode which allows direct sampling and analyte preconcentration. The absorption of phthalates retards the interfacial electron-transfer kinetics and increases the charge-transfer resistance (R_ct). Numerical values of R_ct were extracted from a simulation of electrochemical impedance spectroscopy (EIS) spectra with the corresponding equivalent circuit. Cathodic polarization was employed prior to EIS measurements to effectively eliminate the metal ion interference. The results yielded a detection limit of 0.024 ng/L for diethyl phthalate (DEP) with a linear range from 2.22 ng to 1.11 µg. These results indicate a possibility of developing a household sensor for phthalate determination in Chinese liquor.

Automated on-line monitoring of the TiO2-based photocatalytic degradation of dimethyl phthalate and diethyl phthalate

An automated on-line system for monitoring the TiO₂-based photocatalytic degradation of dimethyl phthalate and diethyl phthalate.