Solid phase extraction using molecular imprinted polymers for phthalate determination in water and wine samples by HPLC-ESI-MS

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.

A Critical Review of Analytical Methods for the Quantification of Phthalates Esters in Two Important European Food Products: Olive Oil and Wine

Phthalic acid esters (PAEs) are a class of chemicals widely used as plasticizers. These compounds, considered toxic, do not bond to the polymeric matrix of plastic and can, therefore, migrate into the surrounding environment, posing a risk to human health. The primary source of human exposure is food, which can become contaminated during cultivation, production, and packaging. Therefore, it is imperative to control and regulate this exposure. This review covers the analytical methods used for their determination in two economically significant products: olive oil and wine. Additionally, it provides a summary and analysis of information regarding the characteristics, toxicity, effects on human health, and current regulations pertaining to PAEs in food. Various approaches for the extraction, purification, and quantification of these analytes are highlighted. Solvent and sorbent-based extraction techniques are reviewed, as are the chromatographic separation and other methods currently applied in the analysis of PAEs in wines and olive oils. The analysis of these contaminants is challenging due to the complexities of the matrices and the widespread presence of PAEs in analytical laboratories, demanding the implementation of appropriate strategies.

A Review of the Analysis of Phthalates by Gas Chromatography in Aqueous and Food Matrices

As a commonly well-known industrial chemical, phthalates are produced in high volumes to be used in various consumer products (e.g., plasticizers, medical devices, construction materials, and toys) to enhance softness, durability, transparency, and flexibility. Phthalates are generally not chemically bonded to the polymer chain of the plastic in which they are mixed. Thus, they may leach, migrate, or evaporate into indoor/outdoor air, and foodstuffs. In this review, a comprehensive overview of several sample preparation methods coupled with gas chromatography for the analysis of phthalates in various kinds of complex matrices, with a focus on the last 20 years' worth of papers. The review begins by highlighting the environmental significance of phthalate pollution along with the various routes to their exposure to general population. Then, the discussion is extended to cover the pretreatment and extraction techniques for phthalates for their quantitation based on gas chromatographic approach. Finally, the present and future challenges for the detection of phthalates in aqueous and food matrices are discussed.

Retention of Phthalates in Wine Using Nanomaterials as Chemically Modified Clays with H20, H30, H40 Boltron Dendrimers

The presence of phthalic acid esters in wines presents a major risk to human health due to their very toxic metabolism. In this paper, aluminosilicate materials were used, with the aim of retaining various pollutants and unwanted compounds in wine. The pollutants tested were di-butyl and di-ethyl hexyl phthalates. They were tested and detected using the gas chromatography-mass spectrometry (CG-MS) analytical technique. Nanomaterials were prepared using sodium bentonite, and were chemically modified via impregnation using three types of Boltron dendrimers of second, third and fourth generations (NBtH20, NBtH30 and NBtH40). The synthesized nanomaterials were characterized using the Brunauer-Emmett-Teller (BET) method, Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis. In this paper, two aspects were addressed: the first related to the retention of phthalate-type pollutants (phthalic acid esters-PAEs) and the second related to the protein and polyphenol levels in the white wine of the Aligoté grape variety. The results obtained in this study have a major impact on PAEs in wine, especially after treatment with NBtH30 and NBtH40 (volumes of 250-500 μL/10 mL wine), with the retention of the pollutants being up to 85%.

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.

Anticonvulsant Activity of Bombyx batryticatus and Analysis of Bioactive Extracts Based on UHPLC-Q-TOF MS/MS and Molecular Networking

Bombyx batryticatus (BB) is an anticonvulsant animal medicine in traditional Chinese medicine (TCM) and acts on the central nervous system. This research aimed to study the anticonvulsant effects of different polarity fractions of extracts from BB and to explore the components conferring anticonvulsant activity. Materials and methods: Crude extracts of BB at 20 g/kg were divided into different polarity fractions (petroleum ether, chloroform, ethyl acetate, water) and were administered to groups of mice before injecting pentylenetetrazol (PTZ) to induce convulsions. The animals were placed in chambers, and their behaviors were recorded for 30 min following the injection. Latency time, percent of protection, convulsion, convulsion rate, and convulsion score were determined for these mice. The compounds present in the different fractions were analyzed, and those from the fraction that conferred anticonvulsant activity were identified by high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF MS) and molecular networking (MN). The chloroform extract fractions (B-C) clearly increased the seizure latency time and protection percentage and decreased the convulsion percentage compared to the control group. The anticonvulsant effect of other extract fractions was not significant. Our study shows that the chloroform extract fractions (B-C) of BB have a significant anticonvulsant effect. We also identified 17 compounds including lumichrome, pheophorbide A, and episyringaresinol 4'-O-beta-d-glucopyranose that were found for the first time. The results of this study may lay the groundwork for studying compounds derived from Bombyx batryticatus and their anticonvulsant effect.

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.

Facile and Selective Determination of Total Phthalic Acid Esters Level in Soft Drinks by Molecular Fluorescence Based on Petroleum Ether Microextraction and Selective Derivation by H2SO4

Determining the level of phthalic acid esters (PAEs) in packaged carbonated beverages is a current need to ensure food safety. High-selectivity and -accuracy identification of individual PAEs can be achieved by chromatographic and mass spectrometric (MS) techniques. However, these methods are slow; involve complicated, expensive instruments in professional laboratories; and consume a large amount of organic solvents. As such, a food analysis method is needed to conveniently and rapidly evaluate multiple contaminants on site. In this study, with the assistance of ultrasound, we quickly determined the total PAEs in soft drinks using 1.5 mL of petroleum ether in one step. Then, we determined the characteristic molecular fluorescence spectrum of all PAEs in samples (excitation (Ex)/emission (Em) at 218/351 nm) using selectively concentrated sulfuric acid derivatization. The relative standard deviations of the fluorescent intensities of mixed solutions with five different PAEs were lower than 7.1% at three concentration levels. The limit of detection of the proposed method is 0.10 μmol L−1, which matches that of some of the chromatographic methods, but the proposed method uses less organic solvent and cheaper instruments. These microextraction devices and the fluorescence spectrometer are portable and provide an instant result, which shows promise for the evaluation of the total level of PAEs in beverages on site. The proposed method successfully detected the total level of PAEs in 38 kinds of soft drink samples from local supermarkets, indicating its potential for applications in the packaged beverage industry.

Application of Molecularly Imprinted Polymers for the Detection of Volatile and Off-Odor Compounds in Food Matrices

Molecularly imprinted polymers (MIPs) are synthetic receptors having specific cavities intended for a template molecule with a retention mechanism that depends on molecular recognition of the targeted constituent. They were initially established for the detection of minor molecules including drugs, pesticides, or pollutants. One of the most remarkable areas where MIPs have potential utilization is in food analysis, especially in terms of volatile compounds which are found in very low concentrations in foods but play a crucial role for consumer preference and acceptance. In recent years, these polymers have been used extensively for sensing volatile organic and off-odor compounds in terms of food quality for selective high-extraction purposes. This review first summarizes the basic principles and production processes of MIPs. Second, their recent applications in the separation, identification, and quantification of volatile and off-odor compounds in food samples are elucidated.

Recent application of molecular imprinting technique in food safety

Due to the extensive use of chemical substances such as pesticides, antibiotics and food additives, food safety issues have gradually attracted people's attention. The extensive use of these chemicals seriously damages human health. In order to detect trace chemical residues in food, researchers have to find several simple, economical and effective tools for qualitative and quantitative analysis. As a kind of material that specifically and selectively recognize template molecules from real samples, molecular imprinting technique (MIT) has widely applied in food samples analysis. This article mainly reviews the application of molecularly imprinted polymer (MIP) in the detection of chemical residues from food in the past five years. Some recent and novel methods for fabrication of MIP are reviewed. Their application of sample pretreatment, sensors, etc. in food analysis is reviewed. The application of molecular imprinting in chromatographic stationary phase is referred. Additionally, the challenges faced by MIP are discussed.

Fast determination of phthalates in mussel samples by micro-matrix solid-phase dispersion (micro-MSPD) coupled with GC–MS/MS

A fast, effective and low cost sample preparation method based on miniaturized matrix solid-phase dispersion (micro-MSPD) combined with gas chromatography coupled to tandem triple-quadrupole-mass spectrometry (GC–MS/MS) has been developed for the determination of six phthalate diesters (DMP, DEP, DBP, BzBP, DEHP and DnOP) in mussel samples. The six target compounds have been included in the list of priority pollutants by United States Environmental Protection Agency. The extraction step was optimized on real spiked mussel coming from Galician Rías by means of a factorial design. The final procedure involved the use of 0.45 g of sample, 0.5 g of dispersant agent (Florisil) and 3 mL of organic solvent (ethyl acetate). The optimized method was validated giving satisfactory analytical performance, low detection limits (0.09 to 6.73 ng g−1 dw) and high recoveries (93 and 114%). The validated method was applied to four real mussel samples coming from Galician Rías.

Application of Molecularly Imprinted Polymers in the Analysis of Waters and Wastewaters

The increase of the global population and shortage of renewable water resources urges the development of possible remedies to improve the quality and reusability of waste and contaminated water supplies. Different water pollutants, such as heavy metals, dyes, pesticides, endocrine disrupting compounds (EDCs), and pharmaceuticals, are produced through continuous technical and industrial developments that are emerging with the increasing population. Molecularly imprinted polymers (MIPs) represent a class of synthetic receptors that can be produced from different types of polymerization reactions between a target template and functional monomer(s), having functional groups specifically interacting with the template; such interactions can be tailored according to the purpose of designing the polymer and based on the nature of the target compounds. The removal of the template using suitable knocking out agents renders a recognition cavity that can specifically rebind to the target template which is the main mechanism of the applicability of MIPs in electrochemical sensors and as solid phase extraction sorbents. MIPs have unique properties in terms of stability, selectivity, and resistance to acids and bases besides being of low cost and simple to prepare; thus, they are excellent materials to be used for water analysis. The current review represents the different applications of MIPs in the past five years for the detection of different classes of water and wastewater contaminants and possible approaches for future applications.

Simple and Efficient Detection Approach of Quercetin from Biological Matrix by Novel Surface Imprinted Polymer Based Magnetic Halloysite Nanotubes Prepared by a Sol-Gel Method

Molecular imprinted polymers coated magnetic halloysite nanotubes (MHNTs-MIPs) were prepared through sol-gel method by using quercetin (Que), APTES and TEOS as template, monomer and cross-linker agent, respectively. The synthesized MHNTs-MIPs were characterized by fourier transform infrared, scanning electron microscope, transmission electron microscope, XRD and vibrating sample magnetometer. Various parameters influencing the binding capacity of the MHNTs-MIPs were investigated with the help of response surface methodology. Selectivity experiments showed that the MHNTs-MIPs exhibited the maximum selective rebinding to Que. Therefore, the MHNTs-MIPs was applied as a solid-phase extraction adsorbent for the extraction and preconcentration of quercetin and luteolin in serum and urine samples. The limits of detection for quercetin and luteolin range from 0.51 to 1.32 ng mL-1 in serum and from 0.23 to 1.05 ng mL-1 in urine, the recoveries are between 95.20 and 103.73% with the RSD less than 5.77%. While the recovery hardly decreased after several cycles. The designed MHNTs-MIP with high affinity, sensitivity and maximum selectivity toward Que in SPE might recommend a novel method for the extraction of flavonoids in other samples like natural products.

Determination of Phthalate Esters in Cosmetics and Baby Care Products by a Biosorbent Based on Lawsone Capped Chitosan and Followed by Liquid Chromatography

This research presents a green synthetic pathway for the preparation of a new biosorbent and eco-friendly extraction process of three phthalate esters: dimethyl phthalate, di-butyl phthalate and benzyl butyl phthalate, from cosmetics and baby care products. Dispersive solid-phase extraction was used based on a new core-shell biomass/sorbent; chitosan-loaded lawsone. The proposed method provides fortunate trapping of phthalate esters in a one-step extraction. Under the optimized extraction conditions, the current work was presented low detection limits (0.03-0.15 ng. g-1), limits of quantification (0.1-0.5 ng·g-1) and reasonable linearity (0.1-10 000 ng. g-1). The applicability of the method was estimated by recovery experiments at different spiking levels (n = 5) for phthalate esters in the real samples.

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.

Rapid in-situ analysis of phthalates in face masks by desorption corona beam ionization tandem mass spectrometry

Phthalates (PAEs) are known as endocrine disruptors that can have adverse effects on human hormonal balance and development. Due to PAEs being semi-volatile chemical compounds, they can sustainably emit from the surfaces of objects containing PAEs. Face masks are commonly used to safeguard human health especially during periods of high prevalence of infectious diseases. As masks come into direct contact with the human respiratory system, PAEs from masks will enter the human body directly from the respiratory system thus potentially threatening human health. In this study, the desorption corona beam ionization (DCBI)-MS/MS method for the rapid in-situ detection of PAEs in face masks was established, which could perform ultra-fast, high-throughput identification and quantitative analysis on 13 kinds of PAEs, and the limits of detection (LODs) were 0.7 μg m^-2 for DAP, BBP, DBP, DPP, DHXP, DEHP, DINP and DDP, 1.4 μg m^-2 for DMEP, DEP, DPhP, DBEP and DNOP. Compared with the traditional liquid chromatography tandem mass spectrometry, this study shows that the DCBI-MS/MS method has the following advantages: 1) short analysis time, less than 1 min; 2) small solvent consumption, less than 10 μL; 3) the PAEs in face masks can be quickly in-situ screened.

Recent advances and applications of molecularly imprinted polymers in solid-phase extraction for real sample analysis

Sample pretreatment is essential for the analysis of complicated real samples due to their complex matrices and low analyte concentrations. Among all sample pretreatment methods, solid-phase extraction is arguably the most frequently used one. However, the majority of available solid-phase extraction adsorbents suffer from limited selectivity. Molecularly imprinted polymers are a type of tailor-made artificial antibodies and receptors with specific recognition sites for target molecules. Using molecularly imprinted polymers instead of conventional adsorbents can greatly improve the selectivity of solid-phase extraction, and therefore molecularly imprinted polymer-based solid-phase extraction has been widely applied to separation, clean up and/or preconcentration of target analytes in various kinds of real samples. In this article, after a brief introduction, the recent developments and applications of molecularly imprinted polymer-based solid-phase extraction for determination of different analytes in complicated real samples during the 2015-2020 are reviewed systematically, including the solid-phase extraction modes, molecularly imprinted adsorbent types and their preparations, and the practical applications of solid-phase extraction to various real samples (environmental, food, biological, and pharmaceutical samples). Finally, the challenges and opportunities of using molecularly imprinted polymer-based solid-phase extraction for real sample analysis are discussed.

Comparison of different types of sorbents for extraction of coumarins

Coumarins, derivatives of cinnamic acid, are found in wines aged in wooden barrels. The lab-made molecularly imprinted polymers (MIP), selective for simple coumarins, were used in three forms, as sorbents in solid phase extraction (SPE) cartridge or pipette tip and coated on to the surface of magnetite for magnetic extraction. MIP-7-hydroxycoumarin had greater selectivity and extraction efficiency (recoveries above 75%, RSDs less than 6%) compared with conventional SPE sorbents (C18 and styrene-divinylbenzene polymeric types). Batch extraction with MIP coated on to magnetic particles was relatively time-consuming compared with conventional and pipette tip SPE. The advantage of pipette tip SPE was reduced solvent volumes. LOQs for MISPE offline coupled with HPLC were less than 1.5 µg mL^-1 and 12 ng mL^-1 for UV and fluorescence detectors, respectively. 6-Methoxy-7-hydroxycoumarin and 4-methyl-7-hydroxycoumarin were detected in Slovak Tokaj wines using method with coumarin-specific sorbents.

Monitoring Phthalates in Table and Fortified Wines by Headspace Solid-Phase Microextraction Combined with Gas Chromatography-Mass Spectrometry Analysis

Phthalates are a class of endocrine disruptors extensively used in plastic production as plasticizers, and as a result, they can be found in foods as a result of their migration ability. The occurrence of phthalates was monitored in 20 Portuguese wines using a simple, reliable, and environmentally friendly analytical method, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry. Satisfactory figures of merit of method, linearity (correlation coefficient of ≥0.992), recovery (80.3-107.6%), precision (relative standard deviation of <13%), and limits of detection (0.03-0.11 μg/L) and quantification (0.09-0.36 μg/L) were achieved. Dibutyl phthalate and di-n-octyl phthalate were found in measurable quantities in table and fortified wines. The obtained results revealed that these wines do not represent any concern for human exposure, because their concentrations were lower than the tolerable daily intakes established by the European Food Safety Authority.

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.

Migration regularity of phthalates in polyethylene wrap film of food packaging

As a kind of polymer material additive, phthalic acid esters (PAEs) are widely used in food industry. However, PAEs are environmental endocrine disruptors with reproductive toxicity and teratogenic carcinogenicity, which are difficult to be degraded in the natural environment. In this paper, gas chromatography-mass spectrometer (GC-MS) methods for PAEs in polyethylene wrap film were optimized. For diisobutyl phthalate (DIBP) and dibutyl phthalate (DBP) that were mainly detected, the method had a good linearity in 1 to 500 ng/g. Then, we confirmed that the migration of DIBP and DBP from polyethylene wrap film increased with time and temperature. It is found that the migration law in different food simulations well followed the migration dynamics first-level model. The rate constant K₁ and initial release rate V₀ are inversely proportional to the polarity of the simulated liquid. We hope that this study can serve as a valuable reference for further research on the migration of food packing materials. PRACTICAL APPLICATION: In this paper, we present a simple example of applying migration model to evaluate the migration behaviors of PAEs in food packaging materials along with their hazardous properties. It can serve as a valuable reference for further research on the migration of food packing materials.

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.

Coumarins content in wine: application of HPLC, fluorescence spectrometry, and chemometric approach

In this work, high performance liquid chromatography (HPLC) and fluorescence spectrometry methods for determination of natural coumarins in Tokaj wine were developed and compared. Molecularly imprinted solid phase extraction procedure was applied for sample preparation. The separation of esculin, coumarin, herniarin, 4-methylumbelliferone, scoparone, scopoletin was performed on core-shell C18 type of stationary phase (100 × 4.6 mm, 5 µm) with a gradient elution of mobile phase containing 1% aqueous solution of acetic acid and methanol, UV-VIS (280 nm for coumarin) and fluorescence detection (Ex 320 nm, Em 450 nm for other coumarins). The HPLC method was validated in term of linearity, limit of detection, limit of quantification, precision and accuracy. Fluorescence detection offers high sensitivity with limit of detection in the ng mL^-1 range. Scopoletine and 4-methylumbelliferone were identified and quantified in tested wines. Emission spectral data, synchronous fluorescence spectra of coumarins from fluorescence spectrometry and total concentrations of coumarins quantified by the HPLC method were used in the partial least squares regression. The linear regression between the concentrations predicted by the partial least squares model versus true values obtained by HPLC method confirmed good agreement between the two methods.

Development and validation of an ultra high performance liquid chromatography-tandem mass spectrometry method for the determination of phthalate esters in Greek grape marc spirits

An Ultra High Performance Liquid Chromatography - Tandem Mass Spectrometry method has been developed for the analysis of 12 phthalate esters in Greek grape marc spirits. The phthalates were separated on a U-VDSpher PUR 100 C18-E (100 mm x 2.0 mm, 1.8 μm) column by gradient elution. The analytes were ionized by positive electrospray ionization using the multiple reaction monitoring mode. The standard addition method was used for quantification and the Student's t-test was carried out to evaluate the matrix effect. The accuracy of the method was assessed by recovery experiments resulting in values from 81.6 to 109.6%. The detection limits ranged from 0.3 to 33.3 μg L^-1.The proposed method was validated and successfully applied to the analysis of 45 samples collected from Greece and Cyprus. All phthalate esters proved to be present at least once in the analysed grape marc spirits samples, except only in cases of diphenyl phthalate and diisodecyl phthalate, while for the regulated phthalates only bis (2-ethylhexyl) phthalate was quantified above the legislative concentration limits.

An online field-assisted micro-solid-phase extraction device coupled with high-performance liquid chromatography for the direct analysis of solid samples

Herein, a total online device based on field-assisted extraction (FAE), micro-solid-phase extraction (μ-SPE), and high-performance liquid chromatography (HPLC) was designed. Solid samples were pretreated with ultrasound-microwave synergic effects, and then the extract was cleaned up online with a monolithic column, followed by HPLC analysis. The cross-actions between ultrasound and microwave along with other extraction parameters were studied systematically. The efficiency of this online method was verified in the determination of polycyclic aromatic hydrocarbons (PAHs) in foods and tetracycline antibiotics (TCAs) in cosmetic samples. The detection limits of nine PAHs including fluorene, phenanthrene, anthracene, fluoranthene, benzo[k]fluoranthene, benz[a]anthracene, benzo[b]fluoranthene, pyrene, and benzo[a]pyrene were all within 0.075-0.30 μg/kg, as well as four TCAs including oxytetracycline, tetracycline, chlortetracycline, and doxycycline were within 0.02-0.06 μg/kg. Six PAHs were found in roast potatoes and baked fish and the recoveries were in the range of 71.5-119.7% with RSDs of 0.2-10.9% (n = 3). The recoveries for TCAs in cosmetic samples were in the range of 75.3-118.0% with RSDs lower than 8.2% (n = 3). Compared with those offline methods, this total online FAE-μ-SPE-HPLC method not only simplifies the operation process, but also increases the precision and accuracy. Beyond trace analytes analysis in solid and semi-solid matrixes, application of this total online analysis method can also be extended to investigate field-assisted extraction mechanisms. Graphical abstract.

A low-cost biosorbent-based coating for the highly sensitive determination of organochlorine pesticides by solid-phase microextraction and gas chromatography-electron capture detection

In this study, an environmentally friendly and low-cost biosorbent coating was evaluated, for the first time, as the extraction phase for solid-phase microextraction (SPME) supported on a nitinol alloy. The characterization of the new fiber was performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The applicability of the biosorbent-based fiber in the determination of δ-hexachlorocyclohexane, aldrin, heptachlor epoxide, α-endosulfan, endrin and 4,4'-DDD in water samples was verified, with separation/detection by gas chromatography coupled to electron capture detection (GC-ECD). The influencing parameters (temperature, extraction time and ionic strength) were optimized simultaneously using a central composite design. The optimum conditions were: extraction time of 80min at 80°C and sodium chloride concentration of 15% (w/v). Satisfactory analytical performance was achieved with limits of detection (LOD) between 0.19 and 0.71ngL^-1 and limits of quantification (LOQ) between 0.65 and 2.38ngL^-1. The relative recoveries for the analytes were determined using river and lake water samples spiked at different concentrations and ranged from 60% for α-endosulfan to 113% for δ-hexachlorocyclohexane, with relative standard deviations (RSD) lower than 21%. The fiber-to-fiber reproducibility (n=3) was also evaluated and the RSD was lower than 14%. The extraction efficiency obtained for the proposed biosorbent coating was compared to a commercially available DVB/Car/PDMS coating. The proposed fiber provided very promising results, including LODs at the level of parts per trillion and highly satisfactory thermal and mechanical stability.