A rapid and simple HPLC–FLD screening method with QuEChERS as the sample treatment for the simultaneous monitoring of nine bisphenols in milk

Assessing dietary bisphenol A exposure among Koreans: comprehensive database construction and analysis using the Korea National Health and Nutrition Examination Survey

Bisphenol A (BPA) exposure primarily occurs through dietary intake. This study aimed to estimate the extent of dietary BPA exposure among Koreans. A thorough literature search was conducted to establish a BPA content database encompassing common foods consumed in Korea, including various food raw materials and processed food products. Dietary exposure levels were estimated by integrating the constructed BPA database with comprehensive nationwide 24 h-dietary recall datasets. The finding revealed that dietary BPA exposure was low for most Koreans, with a mean of 14.5 ng/kg bw/day, but was higher for preschool-age children (over 23 ng). Canned foods accounted for 9-36% of the total dietary exposure of the highest dietary exposure groups; while across all age groups, a considerable amount was derived from canned tuna, contribution of canned fruits and canned coffee (milk-containing) was high for preschool-age children and adults, respectively. Notably, for adults, a substantial proportion also stemmed from beer packaged in cans. While diet contributed over 80% of aggregate exposure for most age groups, preschool-age children experienced 60% exposure through diet due to additional exposure from indoor dust. Even at the high exposure scenario, aggregate BPA exposure levels remained lower than the current tolerable daily intake (TDI) set by the Korean agency (20 μg/kg bw/day). Nevertheless, most Koreans were exposed to BPA levels surpassing the strictest TDI (0.2 ng/kg bw/day) set by the European Food Safety Authority.

Bisphenol A and its analogues: from their occurrence in foodstuffs marketed in Europe to improved monitoring strategies-a review of published literature from 2018 to 2023

In this review article, the research works covering the analytical determination of bisphenol A (BPA) and its structural analogues published from 2018 to present (February 2024) were examined. The review offers an overview of the concentration levels of these xenoestrogens in food and beverages, and discusses concerns that these may possibly pose to the human health and scrutinises, from an analytical perspective, the main biomonitoring approaches that are applied. This comes as a natural evolution of a previous review that covered the same topic but in earlier years (up to 2017). As compared to the past, while the volume of published literature on this topic has not necessarily decreased, the research studies are now much more homogeneous in terms of their geographical origin, i.e., Southern Europe (mainly Italy and Spain). For this reason, an estimated daily intake of the European population could not be calculated at this time. In terms of the analytical approaches that were applied, 67% of the research groups exploited liquid chromatography (LC), with a detection that was prevalently (71%) afforded by mass spectrometry, with over one-fourth of the research teams using fluorescence (26%) and a minority (3%) detecting the analytes with diode array detection. One-third of the groups used gas chromatography (GC)-mass spectrometry achieving comparatively superior efficiency as compared to LC. Derivatisation was performed in 59% of the GC studies to afford more symmetrical signals and enhanced sensitivity. Although the contamination levels are well below the threshold set by governments, routinely biomonitoring is encouraged because of the possible accumulation of these contaminants in the human body and of their interplay with other xenoestrogens.

Covalent organic framework reinforced hollow fiber bar for extraction and detection of bisphenols from beverages

Bisphenols (BPs) can migrate from packaging materials into foods, resulting in potentially harmful residues. For example, accumulation of BPs is associated with endocrine disorders. Owing to matrix effects, development of an effective and eco-friendly sample pretreatment would be helpful for BPs detection in beverages packed in plastic containers. In this work, an extraction bar, composed of hollow fiber (HF) functionalized with covalent organic frameworks (COF@Tp-NDA) and 1-ocanol, was prepared for extraction of five BPs simultaneously. The synergistic effect of COF@Tp-NDA and 1-octanol improved the extraction efficiency of BPs from milk-based beverage, juice, and tea beverage. Under optimal conditions, limits of detection ranged from 0.10 to 2.00 ng mL-1 (R2 ≥ 0.9974) and recoveries ranged from 70.1 % to 106.8 %. This method has the potential to enrich BPs, supporting their accurate determination in complex beverages.

Bisphenol A in dairy products, amount, potential risks, and the various analytical methods, a systematic review

This systematic study deals with the amount of bisphenol A (BPA) in milk and dairy products, its analytical methods, and risk assessment. Milk is one of the drinks that has a high consumption. Bisphenol A can be present both in raw milk and its amount undergoes changes during the pasteurization process. This review was conducted by searching for the keywords Bisphenol A, BPA milk, dairy product, cheese, cream, butter, yogurt, measurement, detection, and analysis in different databases. The search was done in three databases, Scopus, PubMed and Science Direct. The largest number of studies on the determination of bisphenol A belonged to Asian and European countries. The amount of bisphenol A in milks was observed in the range from ND to 640 ng/mL. Furthermore, the amount of BPA in the tested cheese samples was observed in the ND range up to 6.1 ng/g and in the yogurt samples in the ND range up to 4.4 ng/g. The most used analytical method was based on liquid chromatography. The most used solvent for extraction was methanol or acetonitrile. HQ (Hazard Quotient) was also calculated in some studies. There was no risk in terms of milk consumption due to BPA contamination in extracted data.

Assessing Matrix Solid-Phase Dispersion Extraction Strategies for Determining Bisphenols and Phthalates in Gilthead Sea Bream Samples

Microplastics (MPs) and nanoplastics (NPs) are widely spread in the environment, generating significant concern due to their potential impact on environmental health. Marine species usually ingest plastic fragments, mistaking them for food. Many toxic compounds, such as plastic additives that are not chemically bound to the plastic matrix, can be released from MPs and NPs and reach humans via the food chain. This paper highlights the development and validation of a straightforward solid-liquid extraction clean-up procedure in combination with a matrix solid-phase dispersion method using high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) detection, enabling facile, precise, and reliable identification and quantitation of a total of six bisphenols and phthalates in gilthead sea breams. Under the optimized conditions, the developed method showed good linearity (R2 > 0.993) for all target compounds. The recoveries obtained were between 70 and 92%. The relative standard deviations (RSDs) for reproducibility (inter-day) and repeatability (intra-day) were less than 9% and 10%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the target compounds ranged from 0.11 to 0.68 µg/kg and from 0.37 to 2.28 µg/kg, respectively. A new, efficient extraction methodology for the determination of BPA, BPS, BPF, DBP, DEP, and DHEP in gilthead seabream has been optimized and validated.

A flexible electrochemical sensor for bisphenol A detection based on photoinitiated molecular imprinting on CdS functionalized carbon felt

Long-term and excessive exposure to bisphenol A (BPA) has an extremely detrimental effect on human health and ecological system. Hence, there is an urgent need to develop a sensitive and selective sensor for precisely monitoring BPA levels. In this work, a flexible and tailor-made electrochemical sensor for BPA has been fabricated based on in situ photopolymerization of molecular imprinting on cadmium sulfide (CdS) modified carbon felt (MIP@CdS-CF). It is worth nothing that CdS acts as a photocatalyst to enhance the capacity of photopolymerization, accordingly upgrading imprinting efficiency. Meanwhile, carbon felt (CF) exhibits attractive merits in term of superior electrical conductivity, enlarged electrochemical active areas and unique flexibility. Consequently, the novel MIP@CdS-CF electrochemical sensor shows superior sensitivity, high selectivity, extraordinary reproducibility and stability to detect BPA. The detection limit is 1.5 nM, which is lower than those of previously reported electrochemical sensors for the detection of BPA. More importantly, this newly developed electrochemical sensor can be utilized for detecting BPA in plastic bottles with satisfactory results.

Simultaneous Quantification of 16 Bisphenol Analogues in Food Matrices

Exposure to bisphenol analogues can occur in several ways throughout the food production chain, with their presence at higher concentrations representing a risk to human health. This study aimed to develop effective analytical methods to simultaneously quantify BPA and fifteen bisphenol analogues (i.e., bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol S, bisphenol Z, bisphenol TMC, and tetramethyl bisphenol F) present in canned foods and beverages. Samples of foods and beverages available in the Swiss and EU markets (n = 22), including canned pineapples, ravioli, and beer, were prepared and analyzed using QuEChERS GC-MS. The quantification method was compared to a QuEChERS LC-MS/MS analysis. This allowed for the selective and efficient simultaneous quantitative analysis of bisphenol analogues. Quantities of these analogues were present in 20 of the 22 samples tested, with the most frequent analytes at higher concentrations: BPA and BPS were discovered in 78% and 48% of cases, respectively. The study demonstrates the robustness of QuEChERS GC-MS for determining low quantities of bisphenol analogues in canned foods. However, further studies are necessary to achieve full knowledge of the extent of bisphenol contamination in the food production chain and its associated toxicity.

Ten bisphenol analogues in Chinese fresh dairy milk: high contribution ratios of conjugated form, importance of enzyme hydrolysis and risk evaluation

This study investigated concentration levels of ten bisphenols (BPs) in 13 Chinese commercial fresh low temperature dairy milk samples (fresh milk) of main local and national brands with or without enzyme hydrolysis. The results showed that at least two BPs were detected in each fresh milk sample without enzyme hydrolysis and the respective mean concentrations of bisphenol AF (BPAF), bisphenol B (BPB), bisphenol C (BPC), bisphenol F (BPF), bisphenol A (BPA), bisphenol S (BPS), bisphenol AP (BPAP), bisphenol PP (BPP), bisphenol Z (BPZ), and bisphenol E (BPE) were 0.73, 0.61, 1.86, 0.87, 0.42, 0.11, 1.06, 1.42, 1.5, and 0.04 ng/mL, while their respective detection frequencies ranged from 23.1-92.3%. These results indicated the frequent detection of BPs in fresh milk samples. With enzyme hydrolysis, the respective mean concentrations of BPAF, BPA, BPB, BPC, BPF, BPS, and BPAP were increased 7.1-107.1%, indicating the long-ignored importance of enzyme hydrolysis. The respective average estimated daily intakes (EDIs) of BPA by adult and children in China via fresh milk were 32.5 and 37.5 ng/kg bw/d, indicating that BPA in fresh milk was a crucial source to human. Six out of nine other BPs had higher average EDIs than that of BPA, among which the EDI of BPAP was almost three times that of BPA, suggesting the widespread contamination of other BPs in Chinese fresh milk.

Determination of Parabens and Phenolic Compounds in Dairy Products through the Use of a Two-Step Continuous SPE System Including an Enhanced Matrix Removal Sorbent in Combination with UHPLC-MS/MS

Dairy products can be contaminated by parabens and phenolic compounds from a vast variety of sources, such as packaging and manufacturing processes, or livestock through feed and environmental water. A two-step continuous solid-phase extraction (SPE) and purification methodology was developed here for the determination of both types of compounds. In the first step, a sample extract is passed in sequence through an EMR-lipid sorbent and an Oasis PRiME HBL sorbent to remove fat and preconcentrate the analytes for subsequent detection and quantification by UHPLC-MS/MS. This method enabled the determination of 28 parabens and phenolic contaminant with excellent recovery (91-105%) thanks to the SPE sorbent combination used. The proposed method was validated through the determination of the target compounds, and was found to provide low detection limits (1-20 ng/kg) with only slight matrix effects (0-10%). It was used to analyse 32 different samples of dairy products with different packaging materials. Bisphenol A and bisphenol Z were the two phenolic compounds quantified in the largest number of samples, at concentrations over the range of 24-580 ng/kg, which did not exceed the limit set by European regulations. On the other hand, ethylparaben was the paraben found at the highest levels (33-470 ng/kg).

Determination of trace bisphenols in milk based on Fe3O4@NH2-MIL-88(Fe)@TpPa magnetic solid-phase extraction coupled with HPLC

Herein, a covalent organic framework (COF) was grown on a magnetic metal-organic framework (MOF) by a solvothermal method for the efficient extraction of bisphenols (BPs). The magnetic solid-phase extraction (MSPE) of four bisphenols (bisphenol A, bisphenol B, bisphenol AF and bisphenol C) was carried out without adjusting the pH and salt concentration. When 30 mg Fe₃O₄@NH₂-MIL-88(Fe)@TpPa was used to adsorb for 25 min, 6 mL methanol was used to elute for 20 min, and the extract was detected by high-performance liquid chromatography (HPLC). The proposed method has a low detection limit of 0.011-0.036 ng mL^-1, a wide linear range of 0.05-100 ng mL^-1, and a correlation coefficient (R²) of 0.9980-0.9998. The intra-day and inter-day precisions are 0.74-2.54% and 1.68-3.72%, respectively. Bisphenol A was determined by applying the proposed method to the determination of actual milk samples. The standard addition experiment showed that the relative recovery of the four bisphenols was 85.70-119.7%. Pseudosecond-order, first-order, Langmuir and Freundlich models were applied to explore the adsorption characteristics of Fe₃O₄@NH₂-MIL-88(Fe)@TpPa. In general, the established Fe₃O₄@NH₂-MIL-88(Fe)@TpPa-MSPE-HPLC-UV method exhibits attractive sensitivity, simple manipulation, and excellent reusability, and it has excellent prospects for the detection of trace BPs in complex milk matrices.

β-cyclodextrin-functionalized magnetic graphene oxide for the efficient enrichment of bisphenols in milk and milk packaging

In this work, β-cyclodextrin-functionalized magnetic graphene oxide (NiFe₂O₄@GO@β-CD) was synthesized and employed as magnetic solid-phase extraction adsorbent for the extraction of bisphenols before high performance liquid chromatography analysis. The modification of β-cyclodextrin could enhance the adsorption performance of NiFe₂O₄@GO@β-CD towards bisphenols through the host-guest interaction and hydrogen-bond interaction. Under the optimal conditions, good linearities between peak area and concentration of bisphenols (1 - 300 μg L^-1, r ≥ 0.9989) were obtained with the limits of detection (S/N = 3) in the range of 0.050 - 0.10 μg L^-1. The recoveries of bisphenols in milk and milk packaging ranged from 78.0% to 101.6%. Moreover, NiFe₂O₄@GO@β-CD showed stable chemical properties and good reusability with the recoveries of bisphenols remained above 80.0% after 12 MSPE cycles. The adsorption characteristics of NiFe₂O₄@GO@β-CD towards bisphenols fitted well with the pseudo-second-order kinetic model and Langmuir model. The hydrogen-bond interaction, π-π interaction, host-guest interaction and electrostatic interaction between sorbent and bisphenols played important role during the adsorption process. The developed method showed potential applications for the analysis of trace bisphenols in milk and milk packaging.

Three-dimensional flower-like SnS2 materials for dispersive solid-phase extraction of endocrine-disrupting phenols

In this study, three-dimensional flower-like tin disulfide materials were prepared, and a highly efficient dispersive solid-phase extraction method was developed using the obtained three-dimensional tin disulfide adsorbents for the preconcentration and determination of six endocrine-disrupting phenols in combination with high-performance liquid chromatography-ultraviolet detection. Several important experimental parameters influencing extraction efficiency were investigated, including the amount of adsorbent, ultrasound time, sample solution pH, sample volume, type of elution solvent, desorption time, and the number of desorption times. Under the optimized experimental conditions, the developed method showed good linearity with the determination coefficients of 0.993-0.998 in the linear range of 0.5-400 ng/ml and low limits of detection in the range of 0.15-1.0 ng/ml, as well as satisfactory intra-day and inter-day precisions with relative standard deviations of 0.1-9.8%. Finally, the proposed method was successfully applied for the enrichment and determination of trace endocrine-disrupting phenols in milk, tea beverage, and plastic bottled water samples, and acceptable recoveries were obtained from 70.1% to 119.1% under four different spiked concentration levels. The results showed that the three-dimensional tin disulfide materials had great potential for the extraction of endocrine-disrupting phenols contaminants in environmental and food samples.

Evaluation of Chemical Contaminants in Conventional and Unconventional Ragusana Provola Cheese

Organic contaminants belonging to various classes (plasticizers, bisphenols, pesticides, PCBs, and PAHs,) were analyzed in samples of provola cheese produced from Friesian dairy cows fed with a conventional diet (group CTR), and an unconventional diet (group BIO) enriched with olive cake (OC). The results show that for most determined contaminants, the differences between the two diets were very slight, indicating that the contamination does not depend on the olive cake integrated in the unconventional diet. The results also indicate that the minimal contamination could result from environmental contamination or the production process. It can be concluded that unconventional provola is as safe for the consumer as conventional provola.

Research Advances in the Analysis of Estrogenic Endocrine Disrupting Compounds in Milk and Dairy Products

Milk and dairy products are sources of exposure to estrogenic endocrine disrupting compounds (e-EDCs). Estrogenic disruptors can accumulate in organisms through the food chain and may negatively affect ecosystems and organisms even at low concentrations. Therefore, the analysis of e-EDCs in dairy products is of practical significance. Continuous efforts have been made to establish effective methods to detect e-EDCs, using convenient sample pretreatments and simple steps. This review aims to summarize the recently reported pretreatment methods for estrogenic disruptors, such as solid-phase extraction (SPE) and liquid phase microextraction (LPME), determination methods including gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), Raman spectroscopy, and biosensors, to provide a reliable theoretical basis and operational method for e-EDC analysis in the future.

Electrochemical monitoring of bisphenol-s through nanostructured tin oxide/Nafion/GCE: A solution to environmental pollution

Over the past few decades, phenolic compounds have been broadly exploited in the industries to be utilized in several applications including polycarbonate plastic, food containers, epoxy resins, etc. One of the major compounds in phenolics is Bisphenol-S (BPS) which has dominantly replaced Bisphenol-A in several applications. Phenolic compounds are extensively drained into the environment without proper treatment and cause several health hazards. Thus, to tackle this serious problem an electrochemical sensor based on SnO₂/GCE has been successfully engineered to monitor the low-level concentration of BPS in water samples. The fabrication of SnO₂ nanoparticles (SnO₂ NPs) was confirmed through FTIR, XRD, and TEM to examine the size, crystallinity, internal texture, and functionalities of the prepared material. The fabricated material was exploited as a chemically modified sensor for the determination of BPS in water samples collected from different sources. Under optimal conditions such as scan sweep 100 mV/s, PBS electrolyte pH of 6, potential window (0.3-1.3 V), the proposed sensor manifested an excellent response for BPS. The LOD of the present method for BPS was calculated as 0.007 μM, respectively. Moreover, the stability and selectivity profile of SnO₂/GCE for BPS in the real matrix was examined to be outstanding.

An Overview of Aptamer-Based Sensor Platforms for the Detection of Bisphenol-A

Endocrine disruptive compounds are natural or anthropogenic environmental micropollutants that alter the function of the endocrine system ultimately damaging the metabolism. Bisphenol A (BPA) is the most common of these pollutants and it is often used in epoxy coatings and polycarbonates as a plasticizer. Therefore, monitoring BPA levels in different environments is very important and challenging. In recent years, an increasing number of BPA detection methods have been proposed. This article presents a critical review of aptamer-based electrochemical, fluorescence-based, colorimetric, and several other BPA detection platforms published in the last decade. Furthermore, a statistical evaluation has been made using principle component analysis showing analytical performance parameters do not create very different clusters. Comparisons to other BPA detection methods are also presented so that the reader has an overall literature overview.

Metabolic profiling of bisphenol A diglycidyl ether in vitro and in vivo

Bisphenol A diglycidyl ethers (BADGE) is one class of human-made chemicals, and it is one of the most widely used raw materials for epoxy resins. As an active compound, BADGE undergoes biotransformation in vitro and in vivo. However, there is a limited understanding of the biotransformation of BADGE and toxicity studies on transformation products. We conducted comprehensive research on the metabolic transformation of BADGE in vitro and in vivo. The results showed that 12 metabolites and 7 metabolites were identified in vitro and in vivo, respectively. Four biotransformation products, including M1 (hydrolysis), M3 (dehydroxylation), M10 (carboxylation), and M11 (glucose conjugation), can be found in both in vitro and in vivo samples. The main metabolic pathways were hydroxylation, carboxylation, cysteine (Cys) conjugation, and glucose conjugation. Besides, our results suggested the existence of metabolic differences in BADGE between species and gender. Further, we investigated toxicities of BADGE metabolites in-silico. Importantly, some hydrolysis (M1, M2), hydroxylation (M7), and oxidation (M8) products showed similar or even higher potential toxicity than BADGE depending on the endpoint. These results enrich the biotransformation profiles of BADGE and provide useful information for understanding its biotransformation in humans and a reference for the comprehensive assessment for human health risk.

Covalent organic framework modified carbon cloth for ratiometric electrochemical sensing of bisphenol A and S

A novel ratiometric electrochemical sensor was developed based on a carbon cloth electrodeposited with silver nanoparticles and drop-coated by covalent organic framework (COF-LZU1) for simultaneous determination of bisphenol A (BPA) and bisphenol S (BPS). Carbon cloth exhibited a significantly larger electrochemical active area than common glassy carbon electrodes (27.5 times). Silver nanoparticles not only provided a stable reference signal but also enhanced electroactivity for the oxidation of BPA and BPS. COF-LZU1 with good adsorption performance and large periodic π-arrays promoted the enrichment of BPA and BPS to further increase the current response. Compared with the traditional single-signal electrochemical sensor, the developed ratiometric sensor exhibited better reproducibility and a wider linear range for BPA and BPS from 0.5 to 100 μM with a limit of detection of 0.15 μM. Furthermore, the developed sensor showed excellent stability and superior anti-interference ability. The real sample analysis for BPA and BPS has been successfully carried out in mineral water, electrolyte drink, tea, juice, and beer with recoveries of 88.3-111.7%. The developed ratiometric sensor is expected to be a candidate for the preparation of other electrochemical sensors and the analysis of additional practical samples.

High Performance Liquid Chromatography (HPLC) with Fluorescence Detection for Quantification of Steroids in Clinical, Pharmaceutical, and Environmental Samples: A Review

Steroids are compounds widely available in nature and synthesized for therapeutic and medical purposes. Although several analytical techniques are available for the quantification of steroids, their analysis is challenging due to their low levels and complex matrices of the samples. The efficiency and quick separation of the HPLC combined with the sensitivity, selectivity, simplicity, and cost-efficiency of fluorescence, make HPLC coupled to fluorescence detection (HPLC-FLD) an ideal tool for routine measurement and detection of steroids. In this review, we covered HPLC-FLD methods reported in the literature for the steroids quantification in clinical, pharmaceutical, and environmental applications, focusing on the various approaches of fluorescent derivatization. The aspects related to analytical methodology including sample preparation, derivatization reagents, and chromatographic conditions will be discussed.

Multi-Residue Analysis of Chemical Additives in Edible Vegetable Oils Using QuEChERS Extraction Method Followed by Supercritical Fluid Chromatography

Since the quality and safety of food highly depend on its preservation and protection, the use of food packaging materials increases the risk of chemical contamination of the packaged food by migration. Herein, we focused on antioxidants, photoinitiators, UV absorbers and plasticizers which are extensive additives used in food packaging materials. In the present study, a rapid, simple, green and reliable method was developed and validated for the determination of twelve chemical additives in edible vegetable oils using SFC together with a modified QuEChERS procedure. Under the optimum conditions, twelve additives were separated within 10 min, and the consumption of the organic solvent was significantly reduced, which improved the environmentally friendliness. The performance of the developed method was evaluated. Good linearity (r > 0.999) was obtained in the range of 0.20−20.0 µg/mL and 0.50−20.0 µg/mL, respectively. The limits of detection and limits of quantification of the twelve additives in vegetable oils were 0.05−0.15 µg/mL and 0.15−0.50 µg/mL, respectively. Recoveries of all the chemical additives for the spiked samples were between 60.9% and 106.4%, with relative standard deviations (RSD) lower than 9.9%. The results demonstrated that the proposed method was efficient, reliable and robust for the routine analysis of additives in edible vegetable oils and can be an alternative to the multi-residue analysis of chemical additives for other packaged foods.

Migration of bisphenol A and its related compounds in canned seafood and dietary exposure estimation

The present study sought to investigate the migration of target bisphenols, such as BPA, BPF, BADGE, BADGE·H2O, BADGE·2H2O, and BFDGE in 102 samples of several canned seafood, namely canned Antarctic krill, scallop, oysters, mussel, clam, and mantis shrimp stored for months at different temperatures through a high-performance liquid chromatographic-fluorescence detector (HPLC-FLD) combined with a microwave-assisted extraction method. Except for BFDGE, the other five bisphenols were observed in most of the analyzed samples. The canned shrimp showed the highest migration of BPA (0.089 mg/kg), exceeding the specific migration limit (SML) of BPA (0.05 mg/kg) specified by the European Union (EU), while the migration levels of BADGE and its derivatives were within their SMLs. The migration behavior of bisphenols in the canned seafood was majorly affected by the analytes, storage conditions, and food types. BPA, BADGE·H2O, and BADGE·2H2O were characterized by a rapid migration during the first half of the shelf life, which increased with the increase of temperature, followed by a stabilization or decline of their concentrations for prolonged durations. Besides, the migration of target bisphenols was significantly influenced by the storage temperature in some seafood species. Notably, higher migration level of BPA was found in samples with higher fat content. The average dietary exposure of Chinese adults to BPA, BPF, BADGE·2H2O, BADGE·H2O, and BADGE of canned seafood was estimated at 11.69, 1.21, 6.47, 8.74, and 4.71 ng/kg bw/day, respectively. The target hazard quotient (THQ) values of all the analyzed bisphenols were below 1 for the Chinese adults, suggesting an insignificant exposure to these bisphenols through canned seafood consumption.

QuEChERS sample preparation integrated to dispersive liquid-liquid microextraction based on solidified floating organic droplet for spectrometric determination of sudan dyes: A synergistic approach

In this project, a synergistic approach has been proposed where a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation technique was developed for the extraction of sudan III and sudan IV dyes in different spices prior to its dispersive liquid-liquid microextraction based on solidified floating organic droplet (DLLME-SFO). Initially, the sample was extracted by QuEChERS method and then preconcentrated through DLLME-SFO followed by spectrophotometric detection. All the experimental parameters i.e., volume of extraction solvent, pH, acetonitrile to water ratio, temperature, centrifugation rate and time, and sample volume were optimized. Limit of detection (LOD) calculated for sudan III and sudan IV were 0.42 and 0.35 mg/L, respectively. Excellent recoveries were obtained in the range of 98.29-99.88%. After validation through standard addition methodology, the developed QuEChERS@DLLME-SFO method was successfully applied to determine sudan (III-IV) dyes in real spices samples. Integration of QuEChERS and DLLME-SFO was found to be a suitable substitute to eliminate the usage of costly primary secondary amines and other sorbents. The synergistic approach of QuEChERS and DLLME-SFO with the aid of UV/visible spectrophotometry makes it prompt, cost effective technique with excellent analytical figures of merit.

Occurrence and dietary risk of bisphenols and parabens in raw and processed cow's milk

Raw cow's milk collected from farmers and processed cow's milk purchased from local grocery stores were analysed for the presence of six bisphenols (bisphenol A, bisphenol S, bisphenol F, bisphenol AF, bisphenol B, and bisphenol E) and five parabens (methylparaben, ethylparaben, propylparaben, butylparaben, and benzylparaben). The analytes were determined in their unconjugated form and (after enzymatic deconjugation) as the sum of conjugated and unconjugated compounds. The results show the presence of bisphenols mainly in the processed milk bought in stores while parabens were found in all samples of both raw and processed cow's milk. The average concentration of bisphenol A found in milk from cartons (0.87 ng mL^-1) was greater than in milk from plastic bottles (0.35 ng mL^-1). No such difference was found for parabens. Also, no considerable difference between the content of conjugated and total bisphenols and parabens was found except for ethylparaben. The determined compounds were always found below 2.0 ng mL^-1 and calculations of the hazard quotients and the hazard index have shown that consumption of such milk is safe.

Application of d-SPE before SPE and HPLC-FLD to Analyze Bisphenols in Human Breast Milk Samples

In this study, we propose a simple, cost-effective, and sensitive high-performance liquid chromatography with fluorescence detection (HPLC-FLD) for the simultaneous determination of seven bisphenols (bisphenol F (BPF), bisphenol E (BPE), bisphenol B (BPB), BADGE (bisphenol A diglycidyl ether), BADGE∙2H₂O, BADGE∙H₂O, BADGE∙2HCl) in human breast milk samples. The dispersive solid phase extraction (d-SPE) coupled with solid phase extraction (SPE) procedure performed well for the majority of the analytes with recoveries in the range 57–88% and relative standard deviations (RSD%) of less than 9.4%. During the d-SPE stage, no significant matrix effect was observed thanks to the application of different pairs of salts such as zirconium-dioxide-based sorbents (Z-Sep or Z-Sep +) and primary secondary amine (PSA) or QuEChERS Enhanced Matrix Removal-Lipid (EMR-Lipid) and PSA. The method limits of quantification (mLOQs) for all investigated analytes were set at satisfactory low values in the range 171.89–235.11 ng mL⁻¹. Analyte concentrations were determined as the average value from human breast milk matrix samples. The results show that the d-SPE/SPE procedure, especially with the application of EMR-Lipid and PSA, could be used for further bisphenol analyses in human breast milk samples.

Development and validation of an ultra performance liquid chromatography-tandem mass spectrometry method for twelve bisphenol compounds in animal feed

Bisphenol compounds (BPs) are a group of environmental contaminants with endocrine-disrupting effects both for humans and animals. The present work developed a sensitive analytical method for the detection of multiple BPs in the animal feed based on ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) with post-column ammonium hydroxide (NH₄OH) infusion. A modified QuEChERS method was incorporated into the extraction and purification processes. The limit of detection (LODs) and quantification (LOQs) for the target BPs were in the ranges of 0.02-0.75 μg kg^-1 and 0.04-0.95 μg kg^-1, respectively. Average recoveries were ranged between 82.6% and 112%. The proposed method was successfully applied to determine the concentrations of BPs in 20 actual feed samples, and the preliminary profiles of BPs in products from local feed factories were obtained. Each sample was simultaneously contaminated with at least 2 to 4 BPs, and bisphenol A (BPA) was the dominant analog of BPs found in animal feed.

Validation and Use of an Accurate, Sensitive Method for Sample Preparation and Gas Chromatography-Mass Spectrometry Determination of Different Endocrine-Disrupting Chemicals in Dairy Products

Endocrine disrupting chemicals (EDCs) are exogenous substances capable of altering the human hormone system and causing various diseases such as infertility and cancer as a result. In this work, a method for determining twenty-three different EDCs including parabens, alkylphenols, phenylphenols, organophosphorus pesticides, bisphenol A and triclosan in dairy products was developed. Samples are conditioned by addition of acetonitrile containing 1% formic acid, centrifugation and clean-up of the extract by continuous solid-phase extraction. EDCs in the extract are derivatised by heating in a microwave oven and quantified by gas chromatography-mass spectrometry. The proposed method features good limits of detection (6-40 ng/kg) and precision (relative standard deviation < 7.6%); also, it is scarcely subject to matrix effects (1-20%). EDC recoveries from spiked samples ranged from 80 to 108%. The method was used to analyse a total of 33 samples of dairy products including cow, sheep and goat milk, yoghourt, milkshakes, cheese, cream, butter and custard. Bisphenol A was the individual contaminant detected in the greatest number of samples, at concentrations from 180 to 4800 ng/kg. 2-Phenylphenol and ethylparaben were found in more than one-half, at concentrations over the range 130-3500 and 89-4300 ng/kg, respectively. In contrast, alkylphenols, organophosphorus pesticides and triclosan were detected in none.

Toxic effects of bisphenol A and its analogues on cyanobacteria Anabaena variabilis and Microcystis aeruginosa

In the last decades, the use of bisphenol A has attracted global attention resulting from its actions as an endocrine disrupting compound. In this regard, various bisphenol analogues have been manufactured as a replacement for this compound in consumer products. As a result of the high production volumes, different bisphenol analogues are entered into the terrestrial and aquatic environment, which consequently leads to their increasing contamination and may pose serious risk to organisms. Nevertheless, only few studies have reported on the toxic effect of bisphenol analogues on phytoplankton. Therefore, in this study, the anticyanobacterial activity of six bisphenol analogues and their mixture were investigated for the first time. Bisphenol AF, bisphenol B and bisphenol C (14 d, EC₅₀ 12.88-54.87 mg L^-1) exhibit more toxic effect to both tested species in comparison to bisphenol A (14 d, EC₅₀ 55.27-78.96 mg L^-1). Moreover, data show that mixture of bisphenol analogues (14 d, EC₅₀ 32.32-60.88 mg L^-1) exhibit toxic effect similar to or even stronger than that of bisphenol A. The toxic effect of bisphenol analogues, singly and in combination on the growth of both cyanobacteria species was arranged in the following order: bisphenol AF > bisphenol C> bisphenol B> bisphenol A> bisphenol E> bisphenol BP and bisphenol B> bisphenol AF > bisphenol C> bisphenol A> bisphenol E> bisphenol BP for Anabaena variabilis and Microcystis aeruginosa, respectively. This research aims to assure a basic understanding of the toxic effects of bisphenol analogues on cyanobacteria and provides a more comprehensive view on environmental risk assessment.

Determination of trace bisphenols in functional beverages through the magnetic solid-phase extraction with MOF-COF composite

In this study, a novel porous composite (Fe₃O₄@TAPB-COF@ZIF-8) consisting of metal-organic and covalent organic frameworks was developed and applied to the magnetic solid-phase extraction (MSPE) of bisphenols. The extraction parameters such as the extraction time, solution pH, amounts of adsorbent, and ionic strength were investigated to obtain the best extraction conditions. By optimizing the MSPE, a convenient and sensitive analytical method was established in combination with high-performance liquid chromatography. The method achieved low detection limits (0.04-0.05 ng mL^-1), wide linear range (0.25-1000 ng mL^-1), good repeatability (1.20-4.30%), good reproducibility (1.34-4.03%), and satisfactory recoveries of four functional beverages (66.2-116.6%).

Novel computer-assisted separation prediction strategy for online-enrichment-HPLC-FLD in simultaneous monitoring of bisphenols in children's water bottles

An on-line enrichment-liquid chromatography-fluorescence detection (LC-FD) method was developed for simultaneous determination of nine bisphenols (BPs). In this process, we predicted the separation based on an in-house developed software allowing for calculating both retention time (t_R) and half-peak width (W_1/2) of the solute by mobile phase fraction (φ) under gradient conditions. The proposed strategy was applied to separation prediction of BPs with high accuracy. Under the optimized conditions, good linearity was obtained with the correlation coefficients (R²) ranging from 0.998 to 1.000. The recoveries in spiked samples were 91.3-110.7% with the intra-day and inter-day relative standard deviation ranging 0.4-9.6% and 0.5-10.2%, respectively. The limits of detection and quantification were 0.13-66.7 ng L^-1 and 0.40-200 ng L^-1. The developed approach was used to monitor the nine BPs in 28 children's water bottles. The developed method provides an effective way for monitoring bisphenols in other similar matrix.

A magnetic fluorinated multi-walled carbon nanotubes-based QuEChERS method for organophosphorus pesticide residues analysis in Lycium ruthenicum Murr

In order to meet the requirements of pesticide residues' detection in complex matrix samples, the magnetic fluorinated multi-wall carbon nanotubes (M-F-MWCNTs) were prepared and applied as new QuEChERS clean-up materials. Combined with GC-MS, an improved QuEChERS method was successfully developed for the detection of organophosphorus pesticide residues. The results showed that the M-F-MWCNTs could effectively remove the interfering substances in Lycium ruthenicum Murr. (L. ruthenicum) samples. The recoveries of 10 tested targets were 74.9% to 113.5% with the relative standard deviations (RSDs) of 3.9-14.7%. The experiment results pointed out that the M-F-MWCNTs were qualified as QuEChERS clean-up materials and expected to be applied to other complex matrix samples and pesticide targets.

Comparison of DAD and FLD Detection for Identification of Selected Bisphenols in Human Breast Milk Samples and Their Quantitative Analysis by LC-MS/MS

BACKGROUND

Determination of bisphenols released from packaging material is undoubtedly a difficult and tricky task, requiring the chemical analyst to develop an individual approach to obtain reliable analytical information.

OBJECTIVE

QuECHERS (Quick, Easy, Cheap, Effective, Rugged, and Safe)/dispersive solid-phase extraction (d-SPE) technique and high performance liquid chromatography (HPLC) coupled with modern detection techniques such as diode-array detector (DAD), fluorescence detector (FLD) or tandem mass spectrometry (MS/MS) for the determination of bisphenols such as bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), bisphenol B (BPB), 2-[[4-[2-[4-(Oxiran-2-ylmethoxy)phenyl]propan-2yl]phenoxy] methyl]oxirane (BADGE), 3-[4-[2-[4-(Oxiran-2-ylmethoxy)phenyl]propan-2-yl]phenoxy]propane-1,2-diol (BADGE*H2O), 3-[4-[2-[4-(2,3-Dihydroxypropoxy)phenyl]propan-2-yl]phenoxy]propane-1,2-diol (BADGE*2H2O), 1-Chloro-3-[4-[2-[4-(3-chloro-2-hydroxypropoxy)phenyl] propan-2-yl]phenoxy]propan-2-ol (BADGE*2HCl) in human breast milk samples have been performed.

METHODS

For the analysis of total analytes, prior to the extraction with acetonitrile, a deconjugation step was implemented in a tube by adding 1 mL of the enzymatic solution with the β-Glucuronidase to 5 mL of sample. The mix was homogenized and incubated for 17 h at 37°C. Ten milliliters of acetonitrile, and a QuEChERS salt packet with 4 g anhydrous MgSO4 and 1 g NaCl were added. During the d-SPE step the extract was transferred into tube with 30 mg Z-Sep and 50 mg PSA (and also 150 mg MgSO4 for LC-MS/MS analysis). MeOH-water (20:80, v/v) were added to the dry residue and the extract was reconstituted in 150 µL (25-fold analytes pre-concentration is achieved). Next bisphenols were identified by HPLC-DAD-FLD and quantified by LC-MS/MS equipment.

CONCLUSIONS

During the bisphenols HPLC-DAD-FLD analysis, from 6 min a reinforcement of 15 was used, which allowed analytes to be identified at 750 pg/mL. Application of LC-MS/MS allowed quantification of bisphenols in the range from 2.12 to 116.22 ng/mL in a total 27 human breast milk samples.

HIGHLIGHTS

First QuEChERS/d-SPE coupled with HPLC-DAD-FLD or LC-MS/MS method for the quantification of bisphenols and its analogues in breast milk Faster and cheaper alternative to traditional extraction methods The method was applied for the first biomonitoring of bisphenols and its analogues in breast milk.

The effects of heat treatment and fermentation processes on the formation of furfurals in milk-based dairy products using a QuEChERS technique followed by gas chromatography coupled with triple quadrupole mass spectrometry

A method based on gas chromatography coupled with triple quadrupole mass spectrometry (GC-MS/MS) combined with QuEChERS extraction was developed to detect furfurals, including furfural, 2-acetylfuran, 5-methyl-2-furfural, and 5-hydroxymethyl-2-furfural, in milk-based dairy products. Under the optimized conditions, good linearity was obtained with correlation coefficients (R²) above 0.999, and the recovery values from the spiked samples were 79.0%-115.0% with relative standard deviations (RSDs) less than 13.1%. The limits of detection (LOD_S) were in the range of 0.002-0.02 mg/kg. To investigate the effects of the production process on milk-based dairy products, 55 real samples were analysed. The higher contents of furfurals were observed when higher temperatures were used during heat treatment and fermentation. In addition, the Toxtree and T.E.S.T. software programs were used to predict the risks associated with these four furfurals. Ultimately, safe dairy intake levels were determined.

High-performance liquid chromatography (HPLC)-fluorescence method for determination of bisphenol A diglycidyl ether (BADGE) and its derivatives in canned foods

Bisphenol A diglycidyl ether (BADGE) is used as a raw material for the production of epoxy resins and PVC organosols, which are commonly applied as inner coatings for food cans. BADGE and its derivatives can migrate from coatings to foodstuffs during processing and storage thereby creating adverse health issues. In this work, a method based on high-performance liquid chromatography (HPLC)-fluorescence detection (FLD) method was developed for the rapid determination of BADGE and its five derivatives in canned foods. Modeling software DryLab® was applied for the optimization of separation conditions. An adequate separation was achieved in 5 min including equilibration time, using a core-shell particle column; such application has not been reported so far. Also, the results showed that LOD varied from 0.01 to 0.20 ng/g, while LOQ varied from 0.03 to 0.66 ng/g, and RSD was found to be <8.64%. The analytical recoveries ranged from 70.46 to 103.44%. Excellent validation data revealed that this method is suitable for the investigation of can coating-to-food migration of BADGE and its derivatives. The HPLC-FLD method is rapid, inexpensive and highly efficient, which could be applicable for safety inspection of food contact materials involving BADGE and its derivatives.