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Molecular modifications have been practiced for more than a century and nowadays they are widely applied in food, pharmaceutical, or other industries to manipulate the physicochemical, bioactivity, metabolic/catabolic, and pharmacokinetic properties. Among various structural modifications, the esterification/O-acylation has been well-established in altering lipophilicity and bioactivity of parent bioactive compounds, especially natural polyphenolics, while maintaining their high biocompatibility. Meanwhile, various classic chemical and enzymatic protocols and other recently emerged cell factory technology are being employed as viable esterification strategies. In this contribution, the main motivations of phenolic esterification, including the tendency to replace synthetic alkyl phenolics with safer alternatives in the food industry to improve the bioavailability of phenolics as dietary supplements/pharmaceuticals, are discussed. In addition, the toxicity, metabolism, and commercial application of synthetic and natural phenolics are briefly introduced. Under these contexts, the mechanisms and reaction features of several most prevalent chemical and enzymatic esterification pathways are demonstrated. In addition, insights into the studies of esterification modification of natural phenolic compounds and specific pros/cons of various reaction systems with regard to their practical application are provided. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

New sensing platforms based on screen-printed carbon electrodes modified with composites based on polystyrene sulfonate and oxidized multi-walled carbon nanotubes (PSS/MWCNTs-COOH/SPCE) have been used to develop a novel HPLC method with electrochemical detection (ECD) for the determination of the most used synthetic phenolic antioxidants in cosmetics: butylhydroxytoluene (BHT), butylhydroxyanisole (BHA), tert-butylhydroquinone (TBHQ) and propyl gallate (PG). Optimal separation conditions were achieved using methanol: 0.10 mol L−1 acetate solution at pH 6 as mobile phase with a gradient elution program from 60 to 90% of methanol percentage in 15 min. The electrochemical detection was carried out in amperometric mode using the PSS/MWCNTs-COOH/SPCE at + 0.80 V vs. Ag. Under these optimal separation and detection conditions, the limits of detection (LOD) were between 0.11 and 0.25 mg L−1. These LOD values were better, especially for BHT, than those previously published in other HPLC methods. Linear ranges from 0.37 mg L−1, 0.83 mg L−1, 0.69 mg L−1 and 0.56 mg L−1 to 10 mg L−1 were obtained for PG, TBHQ, BHA and BHT, respectively. RSD values equal or lower than 5% and 8% were achieved for repeatability and reproducibility, respectively. The HPLC-ECD method was successfully applied to analyze different cosmetic samples. Recovery values within 83–109% were obtained in the validation studies. [ABSTRACT FROM AUTHOR]

The application of disposable tableware has increased substantially in recent times due to the rapidly growing food delivery business in China. Synthetic phenolic antioxidants (SPAs) are widely used in food contact materials (FCMs) to delay the process of oxidation; however, their compositions, concentrations, and potential health hazards remain unclear. Therefore, FCMs comprised of five materials obtained from 19 categories (n = 118) in China were analyzed for SPAs concentrations. FCMs have been found to contain a variety of SPAs, with ∑SPAs concentrations ranging from 44.18 to 69,485.12 μg/kg (median: 2615.63 μg/kg). The predominant congeners identified in the sample include 2,4-di-tert-butylphenol (2,4-DTBP), 2,6-di-tert-butylphenol (2,6-DTBP), and 2,6-di-tert-butyl-p-benzoquinone (BHT-Q) with a median concentration of 885.75, 555.45 and of 217.44 μg/kg, respectively. Milky tea paper cups, instant noodle buckets, milky teacups, and disposable cups showed high levels of SPAs. 2,2′-methylenebis(4-methyl-6-tert-butylphenol) (AO 2246) was predominantly detected in polyethylene and polyethylene terephthalate-based products. The migration test identified disposable plastic cups and bowls as the predominant FCMs and 2,4-DTBP as the dominant SPA. The exposure risk of SPAs decreased with age. In children, the estimated daily intake of ∑SPAs from FCMs was determined to be 17.56 ng/kg body weight/day, which was 8.3 times higher than that of phthalic acid esters. The current findings indicate the potential ingestion risk of SPAs during the daily life application of multiple FCM categories. [Display omitted] • 2,4-DTBP and BHT-Q were the dominant SPAs and TPs in FCMs with high concentration. • Milky teacup, instant noodle bucket and disposable cup are major source of SPAs. • Disposable cup and bowl are the most used FCMs with the highest migrating levels. • Migration efficiency of SPAs increased as ethanol content in simulants increased. • The exposure risks for single SPAs decreased with age. [ABSTRACT FROM AUTHOR]

This article is focused on the effectiveness of headspace solid-phase micro-extraction (HS-SPME) for determining 4 synthetic phenolic antioxidants (SPAs, including 2,6-di-tert-butylphenol, 4-tert-butylphenol, 2,4-Di-tert-butylphenol, and butylated hydroxytoluene) in food-grade lubricant samples. The effectiveness of 4 fibre types was compared. 50/30μm DVB/Carboxen/PDMS was found to be the most suitable fibre for the analysis of SPAs in food-grade lubricant samples. SPME conditions (equilibrium/extraction temperature, equilibrium time, extraction time, pH, etc.) were optimized in the laboratory. The recoveries at 3 spiking levels were between 80.7∼109.6% with relative standard deviations (R.S.D%) values between 2.3∼6.2%. The method allowed the limit of quantitation (LoQ) at concentrations below 0.1 mg kg− 1 with GC-MS analysis. A quick method for determining 4 SPAs was build and the limit of detection (LoD) satisfied the maximum residue limit (MRL) of (FDA)21CFR 178.3570(10.0 mg kg− 1 of BHT) without difficulty. Finally, this method was applied to 10 food-grade lubricant samples; 90% of these samples were positive. Butylated hydroxytoluene and 2,4-di-tert-butylphenol were the most commonly found synthetic phenolic antioxidants. [ABSTRACT FROM AUTHOR]

A simple, fast, and reliable liquid–liquid micro‐extraction (LLME) method assisted by thermal ultrasound approach was developed for simultaneous determination of synthetic phenolic antioxidants (SPAs) in edible oils by high‐performance liquid chromatography equipped with ultraviolet detector (HPLC‐UV). The synthetic antioxidants were propyl gallate (PG), butylated hydroxyanisole (BHA), tert‐butylhydroquinone (TBHQ), and butylated hydroxyltoluene (BHT). The best extraction conditions were observed were methanol/acetonitrile (1:1, v/v) as the solvent, ultrasound at 4 min, and a temperature of 40°C. The linearity of the calibration curves for the optimum conditions were R2 > 0.989 for all of the SPAs in a range from 1–200 μg ml−1. Relative standard deviation (RSD %) for five analysis was in range of 2.83% to 4.21%. Limit of detection (LOD) and limit of quantification (LOQ) were obtained in range of 0.012–0.06 and 0.04–0.2 μg g−1, respectively. With regard to recovery, a range of 91%–116% was calculated for the spiked edible oils. [ABSTRACT FROM AUTHOR]

Newly synthesized chemicals are being introduced into the environment without undergoing proper toxicological evaluation, particularly in terms of their effects on the vulnerable neurodevelopment. Thus, it is important to carefully assess the developmental neurotoxicity of these novel environmental contaminants using methods that are closely relevant to human physiology. This study comparatively evaluated the potential developmental neurotoxicity of 19 prevalent environmental chemicals including neonicotinoids (NEOs), organophosphate esters (OPEs), and synthetic phenolic antioxidants (SPAs) at environment-relevant doses (100 nM and 1 μM), using three commonly employed in vitro neurotoxicity models: human neural stem cells (NSCs), as well as the SK-N-SH and PC12 cell lines. Our results showed that NSCs were more sensitive than SK-N-SH and PC12 cell lines. Among all the chemicals tested, the two NEOs imidaclothiz (IMZ) and cycloxaprid (CYC), as well as the OPE tris(1,3-dichloro-2-propyl) phosphate (TDCIPP), generated the most noticeable perturbation by impairing NSC maintenance and neuronal differentiation, as well as promoting the epithelial-mesenchymal transition process, likely via activating NF-κB signaling. Our data indicate that novel NEOs and OPEs, particularly IMZ, CYC, and TDCIPP, may not be safe alternatives as they can affect NSC maintenance and differentiation, potentially leading to neural tube defects and neuronal differentiation dysplasia in fetuses. [Display omitted] • The developmental neurotoxicity of 19 emerging environmental chemicals was assessed. • Neural stem cells were more sensitive to the chemicals than the SK-N-SH and PC12 cell lines. • Among the chemicals tested, IMZ, CYC, and TDCIPP exhibited the most adverse effects. • IMZ, CYC, and TDCIPP impaired NSC maintenance and differentiation, likely via NF-κB. • This study provides valuable insights for the safe use of emerging environmental chemicals. [ABSTRACT FROM AUTHOR]

Although synthetic antioxidants (AOs) and photoinitiators (PIs) are known to be used in printing inks, there are little data on residual concentrations in printing paper products. In the present study, twenty-five PIs, ten AOs, and six transformation products were analyzed in two types of printing paper products, magazines and paperboard food packaging materials, both of which are unavoidable everyday products in our life. Nine AOs and six transformation products can be detected in food packaging materials with total concentrations (geometric mean, GM) of 1.16 × 104 ng/dm2. Twenty-two PIs were detected in food packaging materials with total concentrations (GM) of 1.76 × 104 ng/dm2. These chemicals were also detected in magazines, albeit at low concentrations (GM of AOs: 466 ng/dm2, GM of PIs: 1.17 × 103 ng/dm2). Magazine front covers were found to have much higher concentrations of the target compounds than magazine inside pages. Tris(2,4-di-tert-butylphenyl) phosphate (AO168O), 2,6-di-tert-butyl-4-methylphenol (BHT), bisphenol A (BPA), and benzophenone (BP) were among the predominant chemicals in those printing paper products. Preliminary calculations suggest that dermal exposure to AOs (GM: 6.25 ng/day) and PIs (GM: 17.0 ng/day) via contact with printing paper products is a minor exposure pathway compared to food intake/dust ingestion and is exceedingly unlikely to cause adverse health effects.

Copyright of China Surfactant Detergent & Cosmetics (1001-1803) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Eighteen SPAs in large structural difference can be fast removed by Fe(VI). • E LUMO , N O atom , N alkyl group and especially E LUMO – E HOMO of SPAs affected the reactivity with Fe(VI). • SPA removals were obviously influenced by environmental conditions. • BHT was degraded by H-abstraction, single- and double-oxygen(s) transfer, and coupling. • BHT-Q exerted higher toxicity to S. obliquus than BHT and BHT-CHO. Synthetic phenolic antioxidants (SPAs) have been commonly used in industrial and domestic products to prevent the adverse effects of oxidants such as oxygen. However, attention to the removal of SPAs is scarcely attracted. In this paper, the removal kinetics, influencing factors, transformation mechanisms and toxicity in Fe(VI) oxidation of 18 SPA congeners were investigated in detail. Results showed that propyl gallate (PG), butylated hydroxyanisole (BHA), and tert -butylhydroquinone (TBHQ) had the highest reactivities with Fe(VI), while the reaction rate constant (k app) value of 2,4-di- tert -butylphenyl 3,5-di- tert -butyl-4-hydroxybenzoate (UV120) was the lowest (221.3 M−1 s−1). A robust quantitative structure–activity relationship (QSAR) model between k app and molecular structural descriptors of SPAs was established. The energy gap between the lowest unoccupied molecular orbital (E LUMO) and the highest occupied molecular orbital (E HOMO) was a vital parameter to determine the removal efficiencies of the SPA congeners. Furthermore, the numbers of oxygen atoms and alkyl groups in SPA structures also determined their reactivities with Fe(VI) to some extent. In addition, aqueous 2,6-di- tert -butyl-4-methylphenol (BHT, a representative of SPAs) could be efficiently removed with the increased amount of oxidant, and decreased substrate concentration and slightly alkaline conditions. Seventeen intermediates were identified, and oxidation routes including H-abstraction, single- and double-oxygen(s) transfer, and coupling were deduced. However, H-abstraction inevitably led to the generation of BHT-Q with higher toxicity than parent. These findings provide novel insights into the production and removal of SPA analogs. [ABSTRACT FROM AUTHOR]

An air–assisted liquid–liquid microextraction method for the extraction and preconcentration of trace amounts of some synthetic phenolic antioxidants in biological fluids followed by their determination by gas chromatography–flame ionization detection has been reported. In this method the target analytes are extracted into a few microliters of carbon tetrachloride (extraction solvent) from an aqueous solution by aspirating and dispersing the extraction solvent and sample solution mixture by a syringe. After extraction, phase separation is performed by centrifugation and the enriched analytes in the sedimented phase are determined. The parameters affecting the extraction efficiency including the type and volume of extraction solvent, salt addition, extraction times, and pH are investigated in details. Under the optimum extraction conditions, the method shows low limits of detection and quantification between 0.8–1.8 and 2.7-5.6 ng mL–1, respectively. The method is applied to determine some phenolic antioxidants in biological samples and extraction recoveries are ranged from 63 to 81%. Enrichment factors are obtained between 315 and 405. The method shows good linearities in the range of 3–6000 ng mL-1 with the correlation coefficients higher than 0.996. Relative standard deviations are lower than 8% for intra-day (n=6) and inter-day (n=4) precisions. Finally the proposed method is successfully used for determination of the analytes in urine and plasma samples.

Synthetic phenolic antioxidants (SPAs) have received increasing attention due to the reports of toxicity and environmental contamination. Nevertheless, limited information was available on human burdens of these SPAs, with the exception of 2,6-di- tert -butyl-4-methylphenol (BHT). In our study, BHT as well as six other SPAs were analyzed in human urine samples from United States donors. Three SPA congeners were detected in human urine: BHT, 2,4-di- tert -butylphenol (DBP), and 3- tert -butyl-4-hydroxyanisole (BHA). BHT, which is the congener received most concerns, was detected at low concentrations [geometric mean (GM): 0.06 ng/mL], whereas four of its metabolites were detected at relatively high concentrations (GM: 1.68 ng/mL). Surprisingly, DBP was detected at extremely high concentrations (GM: 18.3 ng/mL). The concentrations of DBP (GM: 25.8 ng/mL), BHT (0.853 ng/mL), and metabolites (GM: 10.5 ng/mL) increased significantly after the urine samples were hydrolyzed by β -glucuronidase (p < 0.01), indicating the prevalence of the conjugated forms of SPAs and their metabolites in human urine. DBP, which has previously received little attention, was the predominant congener, contributing 88.2% and 63.6% to total target concentrations in the urine samples before and after β -glucuronidase hydrolysis, respectively. Thus, previous studies have vastly underestimated the burdens of SPAs to humans. To our knowledge, this is the first study revealing the presence of DBP in human urine. Image 1 • Three SPAs were detected in human urine from U.S. donors. • Four BHT metabolites were also detected. • Total concentrations of phenolic targets are higher than the free concentrations. • DBP was the primary congener in human urine. Unexpectedly high concentrations of DBP were detected in human urine for the first time, which contributed >60% to total target concentrations. [ABSTRACT FROM AUTHOR]

Abstract Synthetic phenolic antioxidants (SPAs) are of emerging concern due to their potential environmental risks. However, the environmental occurrence and fate of SPAs are poorly understood. In this study, 13 SPAs were analyzed in 70 liquid and 21 solid samples from 12 wastewater treatment plants (WWTPs) in 2016 to investigate the distribution and composition of SPAs in different wastewater treatment processes in Canada. Wastewater samples were liquid-liquid extracted and biosolids were treated using ultrasonic assisted solvent extraction. SPAs were analyzed by ultra-performance liquid chromatography-tandem mass spectrometry. The concentrations of total SPAs were in the ranges of 71–3193 ng L−1 in influent, less than method quantification limits (MQLs)-520 ng L−1 in effluent, and 479–4794 ng g−1 in biosolids (dry weight (dw)). SPAs were effectively removed (median >75%) from the liquid stream in most WWTPs. In one aerated lagoon and two primary treatment sites, low removal efficiency (median −26%-43%) was observed for 4- tert -octylphenol (4- t OP). These results indicate that wastewater effluent is a vector for SPAs, including the endocrine disruptor 4- t OP, to aquatic environments. The mass balance approximation found major removal mechanisms are sludge sorption/separation and degradation. A preliminary risk assessment suggested that most SPAs in WWTP effluent were unlikely to pose ecotoxicological risks to aquatic organisms in the receiving waters. Future research should evaluate the environmental risks of SPAs associated with land application of biosolids and investigate the occurrence and fate of the degradation products of these contaminants. Graphical abstract Image 1 Highlights • The single phenolic ring 4- t OP, 2,4-DTBP and BHT were the dominant SPAs in Canadian WWTPs. • Chemically assisted primary treatments showed very low removal efficiency of 4- t OP (−13 ± 43%). • The removal mechanisms included sludge sorption/separation and degradation in WWTP liquid stream. • Most target SPAs were unlikely to pose risks to aquatic organisms in Canadian WWTP effluent receiving waters. [ABSTRACT FROM AUTHOR]

Abstract Synthetic phenolic antioxidants (SPAs) have gained high concerns due to their extensive usages and unintended environmental release via various routes. Their contamination in water system could pose potential threat to aquatic organisms, therefore, the studies on the aquatic toxicology of this kind of chemicals are of high importance. In this research, the developmental toxicities of four commonly used SPAs, including butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tert-butyl hydroquinone (TBHQ), and 2,2′-methylenebis (6-tert-butyl-4-methylphenol) (AO2246) were investigated using the zebrafish embryo toxicity test (ZFET). The results showed that these four SPAs exerted different acute toxicities to zebrafish, and the toxic order, based on their 96 h LC 50 values, was AO2246 > TBHQ > BHA > BHT, and decreased hatching rates were induced for the embryos in BHA, TBHQ and AO2246 exposure groups. Non-lethal exposures of BHA (≤20 μM), TBHQ (≤20 μM), BHT (≤200 μM) and AO2246 (≤2 μM) decreased the heart rates and body lengths of zebrafish in exposure concentration-dependent manners. Diverse morphological deformities, including uninflated swim bladder, pericardial edema, spinal curvature, severe yolk deformation, or abnormal pigmentation, were induced in zebrafish larvae upon SPA treatments. The transcriptional levels of the related genes, examined by quantitative PCR, indicated that the interferences of SPAs with hypothalamic-pituitary-thyroid axis (HPT axis), GH/PRL synthesis and Hedgehog ( hh ) pathway contributed to their developmental toxicities in zebrafish. The up-regulation of pluripotency biomarker, Oct4 , caused the developmental retardation during the early stages of zebrafish embryos in BHA and TBHQ exposure groups. The results obtained herein provided important information on the developmental toxicity of SPAs, which could be very helpful in guiding the risk assessment on their aquatic toxicology. Graphical abstract Unlabelled Image Highlights • SPA exposures induced developmental toxicities in zebrafish embryos and larvae. • Diverse deformities were caused in zebrafish larvae by SPA exposures. • The toxicity order of SPAs to zebrafish based on their 96 h LC 50 values was AO2246 > TBHQ > BHA > BHT. • SPAs caused dysfunctions of HPT axis, GH/PRL synthesis, and hh pathway in zebrafish larvae. • BHA and TBHQ caused early developmental retardation of zebrafish embryos. [ABSTRACT FROM AUTHOR]

Synthetic phenolic antioxidants (SPAs) are an environmental concern due to their persistence nature and bioaccumulation. However, the hepatoxicity and mechanisms of SPAs in aquatic organisms remain poorly understood. In this study, grass carp were exposed to two representative SPAs (BHA and BHT) at environmentally relevant levels (0.1 μM) for 30 days. We observed that BHA and BHT exposure significantly increased the levels of serum aminotransferase (ALT) and aspartate aminotransferase (AST) in grass carp, accompanied by mild inflammatory cell infiltration and irregularity in the shape of hepatocytes. Dihydro ethylenediamine staining showed that BHA and BHT exposure resulted in elevated levels of superoxide levels, accompanied by increased antioxidant enzyme activities (T-AOC, SOD, CAT, GSH-PX) and MDA levels, which is suggestive of oxidative stress responses in the liver of grass carp. Besides, BHA and BHT could dock into the pocket of phosphatidylinositol 3-kinases (PI3K) and thereby inhibiting PI3K/mammalian target of rapamycin (mTOR)/protein kinase B (AKT) signaling cascades. Meanwhile, our results clarified that BHA and BHT could promote autophagosome production and increase the expression of key autophagy proteins, likely due to inhibition of PI3K/mTOR/AKT signaling pathway. Moreover, BHA and BHT could induce apoptotic process by upregulating the expression of Bax, Caspase3 and Caspase8 and downregulating Bcl2 expression. Notably, BHT exhibited more hepatoxicity on the indicators of the apoptosis and oxidative stress than BHA. In summary, our findings demonstrated that BHA and BHT exposure could induce liver damage induced via regulating ROS/PI3K-mediated autophagic hyperactivation, which is a crucial step in triggering hepatocyte death. This study provides novel insight into the potential mechanisms underlying liver damage caused by BHA and BHT in aquatic organisms, and offers a new theoretical basis for ecological risk assessment of SPAs. [Display omitted] • BHA and BHT could induce ROS burst in the liver of grass carp. • BHA and BHT could dock into the pocket of PI3K and promote autophagic hyperactivation. • BHA and BHT could inhibit PI3K/mTOR/AKT signaling cascades. • BHA and BHT could induces apoptotic cell death in liver of grass carp. • BHT exhibited more hepatoxicity than BHA in grass carp. [ABSTRACT FROM AUTHOR]

Butylated hydroxytoluene (BHT) is one of the most commonly used synthetic antioxidants in food, cosmetic, pharmaceutical and petrochemical products. BHT is considered safe for human health; however, its widespread use together with the potential toxicological effects have increased consumers concern about the use of this synthetic food additive. In addition, the estimated daily intake of BHT has been demonstrated to exceed the recommended acceptable threshold. In the present work, using BHT as a case study, the usefulness of computational techniques, such as reverse screening and molecular docking, in identifying protein–ligand interactions of food additives at the bases of their toxicological effects has been probed. The computational methods here employed have been useful for the identification of several potential unknown targets of BHT, suggesting a possible explanation for its toxic effects. In silico analyses can be employed to identify new macromolecular targets of synthetic food additives and to explore their functional mechanisms or side effects. Noteworthy, this could be important for the cases in which there is an evident lack of experimental studies, as is the case for BHT.

To fulfill the growing demand for retarding the oxidation of polymers and minimizing their migration from various products, new macromolecular synthetic phenolic antioxidants (SPAs) have emerged in the market. There is a concern that these SPAs may be released into wastewater streams during their manufacturing and use, eventually ending up in wastewater treatment plants (WWTPs). Nevertheless, information regarding the occurrence of these SPAs in sludge, particularly on a national scale, is scarce. In this study, several macromolecular SPAs and their transformation products (TPs) were investigated in sludge samples from 45 Chinese municipal WWTPs. All 14 analytes were detected in the sludge samples, among which, 12 analytes were first reported in sludge. 2,4,6-tri-tert-butylphenol (AO246) and 2 macromolecular SPAs, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (AO1010) and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (AO1076), were the most dominant SPAs, with geometric mean (GM) concentrations of 547, 212, and 35.2 ng/g dw, respectively. Two TPs, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid (fenozan) and 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH), were found in some sludge samples (48.9-71.1 %) with GM of 45.5 and 12.8 ng/g dw, respectively. By using LC-Q-TOF-MS/MS analysis, we tentatively identified previously unknown TPs of 10 macromolecular SPAs in sludge. This suggests that there are still unclear mechanisms modulating the transformation of these SPAs, which underscores the complexity of their fate. Additionally, using the freshwater photobacteria Vibrio qinghaiensis sp.-Q67 (Q67) as model organism, the acute and chronic EC 50 of the 14 analytes were assessed for ecological risk assessment. By considering toxicity data obtained from algae, daphnia, and fish collected or predicted from various databases, we found that these analytes, including their mixture at low detected concentrations, pose risks to aquatic systems that should not be disregarded. Overall, the current study provides a comprehensive overview of novel SPAs and their TPs in sludge, offering valuable insights for investigating their environmental behavior, fate, and risks., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

A novel and rapid low-density solvent-based dispersive liquid-liquid microextraction technique combined with magnetic solid-phase extraction (MSPE) was developed for preconcentration and separation of synthetic phenolic antioxidants (SPAs) in vegetable oils prior to high-performance liquid chromatography. 1-Heptanol was used as extractant and decanoic acid@Fe3O4 nanoparticles (DA@Fe3O4 NPs) as carrier to retrieve and separate the 1-heptanol. In that manner, the upper extractant containing the SPAs is the target of the MSPE step rather than the SPAs directly. Thanks to the interaction between carboxyl group present on the surface of the magnetic nanoparticles and the alcohol functional group of the extractant, the DA@Fe3O4 NPs facilitates the recollection of the 1-heptanol after extraction. The main parameters affecting the extraction recoveries of four SPAs were investigated, and the proposed method provided a good linearity in the range of 50-2000 ng mL−1, low limits of detection (1.2-5.8 ng mL−1), and good repeatability of the extractions (relative standard deviations ≤6.7%, n = 5), and recoveries were ranged from 90.2% to 99.5%. [ABSTRACT FROM AUTHOR]

In this study, a hybrid composite containing melamine-based covalent organic polymer (MCOP) and ionic liquid (IL) was designed and employed for the functionalization of polymer monolith. The obtained polymer monolithic material was confirmed by scanning electron microscopy, Fourier-transformed infrared spectroscopy, X-ray photoelectron spectroscopy, and thermal gravimetric analysis. A polymer monolith microextraction (PMME) strategy was established based on the monolith for the enrichment of synthetic phenolic antioxidants, exhibiting high sensitivity, good stability and repeatability. Intra-day and inter-day relative standard deviations were both less than 10%. The developed PMME-HPLC method was applied to the preconcentration and determination of synthetic phenolic antioxidants in cosmetic samples and assessed through recovery studies. The developed polymer monolithic material had great potential as a candidate in the preconcentration field for PMME. [ABSTRACT FROM AUTHOR]

Little is known about the occurrence and fate of synthetic phenolic antioxidants (SPAs) and their metabolites in wastewater treatment plants (WWTPs). In this study, inventory, source, mass loading, and discharge of five SPAs, including 2,6-di- tert -butyl-4-methylphenol (BHT) and four of its metabolites were examined, based on the concentrations determined in wastewater influent, primary effluent, final effluent, suspended particulate matter (SPM), and sludge collected from two WWTPs (denoted as WWTP A and WWTP B ) in the Albany area of New York State. The respective median concentrations of sum of SPAs (ΣSPAs = 6 compounds including metabolites) and SPA-metabolites (Σmetabolites = 4 metabolites) were 2455–3330 and 290–465 ng/L in influents, and 1580–1604 and 511–822 ng/L in final effluents. Adsorption to sludge (ΣSPAs ranged as 2420–4680 ng/g dry wt) accounted for ∼1% of the SPA removal. The removal efficiency (RE) for BHT in WWTPs ranged between 62.3% and 76.2%, whereas negative REs were found for SPA-metabolites ([-3020%]-[−65.6%]). WWTP-based mass loading of BHT accounted for ∼4%–10% of the total production volume reported in the USA, whereas ∼1.0% of the annual production of BHT was discharged from WWTP through effluents. BHT present in personal care products was estimated to explain for >91% of the mass loading source into WWTPs. [ABSTRACT FROM AUTHOR]

Synthetic phenolic antioxidants such as propyl gallate (PG) and butylated hydroxyanisole (BHA) are food additives whose levels in foodstuff must be controlled. The purpose of this study is to evaluate, for the first time, the usefulness of graphene as sorbent for the isolation of PG and BHA from complex food sample matrices, by a solid phase extraction (SPE) method. The influence of the eluent type and volume, amount of graphene, sample volume and concentration of antioxidants in the extraction process has been evaluated. Once the process was optimized, extraction yields of 81 and 95% were obtained for PG and BHA respectively. Quantification of the antioxidants was carried out by RP-HPLC with detection at 290 nm, in isocratic mode, using acetonitrile/1% H 3 PO 4 (60/40 v/v) as mobile phase. The proposed method was applied to the quantification of both antioxidants in pre-cooked spaghetti and hard bouillon cube samples. In the spaghetti matrix, which contains both antioxidants, PG and BHA levels were found to be below established legal limits. The hard bouillon cubes, free from both antioxidants, were spiked with different amounts of PG and BHA, and recoveries very close to 100% were attained. [ABSTRACT FROM AUTHOR]

The reversed-phase mode of single drop microextraction has been used as a preparation method for the extraction of some phenolic antioxidants from edible oil samples. Butylated hydroxyl anisole, tert-butylhydroquinone and butylated hydroxytoluene were employed as target compounds for this study. High-performance liquid chromatography followed by fluorescence detection was applied for final determination of target compounds. The most interesting feature of this study is the application of a disposable insulin syringe with some modification for microextraction procedure that efficiently improved the volume and stability of the solvent microdrop. Different parameters such as the type and volume of solvent, sample stirring rate, extraction temperature, and time were investigated and optimized. Analytical performances of the method were evaluated under optimized conditions. Under the optimal conditions, relative standard deviations were between 4.4 and 10.2%. Linear dynamic ranges were 20-10 000 to 2-1000 μg/g (depending on the analytes). Detection limits were 5-670 ng/g. Finally, the proposed method was successfully used for quantification of the antioxidants in some edible oil samples prepared from market. Relative recoveries were achieved from 88 to 111%. The proposed method had a simplicity of operation, low cost, and successful application for real samples. [ABSTRACT FROM AUTHOR]

Three synthetic phenolic antioxidants, tertiary butyl hydroquinone, butylated hydroxytoluene, and butylated hydroxyanisole, were determined in vegetable oil and oil-enriched food by high-performance liquid chromatography (HPLC) with electrochemical detection. The separation was achieved using a reverse-phase column and gradient elution with methanol and 1% acetic acid. The limits of detection and quantification of the analytes were 2–120 lower, higher than those obtained by diode-array detection. The recoveries were 103.3% for tertiary butyl hydroquinone, 97.3% for butylated hydroxyanisole, and 95.2% for butylated hydroxytoluene. The results showed that HPLC with electrochemical detection is suitable for the quantification of low concentrations of phenolic antioxidants in vegetable oil and oil-enriched food with high sensitivity and accuracy. [ABSTRACT FROM PUBLISHER]

In this study, seven synthetic phenolic antioxidant (SPA) analogues were positively found in urban and rural indoor dust samples collected from Shandong province in China, among which the novel 2,4,6-tri- tert -butylphenol (AO 246), 2,6-di- tert -butyl-4-sec-butylphenol (DTBSBP), 2,4-di- tert -butylphenol (DBP) and 4,4'-butylidenebis (2-(1,1-dimethylethyl)-5- methyl-phenol) (AO 44B25) analogues accounted for 29% of total SPA concentrations (∑SPAs). Urban dust showed significantly higher ∑SPA levels (range: 1.56e3 - 2.03e4 ng/g) compared with those in rural indoor dust (668–4.39e3 ng/g, p < 0.05). 2,6-Di-tert-butyl-4-methylphenol (BHT) was the dominate analogue in the urban indoor dust, which constituted of 74% in ΣSPAs. While, varied composition profiles of SPAs were noticed in rural indoor dust, for instance, AO 246 (46%) and BHT (43%) had similar contributions to ∑SPAs. Three BHT transformation products (TPs) were also detected in most of the urban and rural dust samples (>97%), with individual residue level in the same order: 2,6-di- tert -butyl-1,4-benzoquinone (BHT-Q) > 2,6-di-tert-butyl-4-hydroxy- 4-methyl-2,5-cyclo-hexadienone (BHT-quinol) > 3,5-di- tert -butyl-4-hydroxybenzal-dehyde (BHT-CHO). Geometric mean values of total TP concentrations were 555 ng/g and 131 ng/g for urban and rural indoor dust samples, respectively. A preliminary estimated daily intake calculation at dust ingestion scenario suggested additional concerns might be paid to simultaneous exposure of several SPA analogues and TPs besides current focus on BHT exposure risks. [ABSTRACT FROM AUTHOR]

[Display omitted] • COF-based monolith with hydrophilic interaction was first proposed. • Successful embedment of COF into UF monolith was confirmed. • This COF-based monolith was applied as sorbent for in-tube SPME of SPAs. • Efficient SPME was achieved by the combination of HI and π-π stacking interaction. • In-tube SPME-HPLC method with COF-based monolith was proposed for analysis of SPAs. Currently, covalent organic framework-based (COF-based) monolithic columns show excellent application potential for high-efficient sorbent in sample preparation. Hydrophobic and π-π stacking interaction were their primary adsorption mechanisms for extraction. Hydrophilic interaction has not been involved yet. Herein, a novel COF-based monolithic column with hydrophilic interaction and π-π stacking interaction has been fabricated by the embedment of COF TAPB-TPA microspheres into urea–formaldehyde resin (UF) monolith. Due to the excellent adhesion performance of UF, the COF TAPB-TPA microspheres could be steadily embedded into the UF monolith. Taking the advantages of the hydrophilic interaction and the π-π stacking interaction between the COF TAPB-TPA @UF monolith and synthetic phenolic antioxidants (SPAs), the COF TAPB-TPA @UF monolith was adopted as efficient sorbent for in-tube SPME of trace SPAs in edible oils. Several SPME parameters, including the percentage of ACN in the sampling solution and eluent, the collection time span, and the pH value of the sampling solution, were optimized for satisfactory SPME performance. Under the optimized conditions, the LODs of the analytes varied from 0.2 to 1.2 ng/mL, and the recoveries ranged from 78.1 % to 98.4 % for sunflower oil samples at three spiked levels, with the RSDs lower than 7.2 %, indicating the superior extraction capacity of the COF TAPB-TPA @UF monolith as well as the promising feasibility of the proposed in-tube SPME-HPLC method. This work lighted a facile way for COF-based monoliths with hydrophilic interaction, and further expanded their applications for sample preparation. [ABSTRACT FROM AUTHOR]

A simple, rapid, organic-solvent- and sample-saving pretreatment technique, called dispersive liquid-liquid microextraction, was developed for the determination of six synthetic phenolic antioxidants from edible oils before high-performance liquid chromatography with diode array detection. The entire procedure was composed of a two-step microextraction and a centrifugal process and could be finished in about 5 min, only consuming only 25 mg of sample and 1 mL of the organic solvent for each extraction. The influences of several important parameters on the microextraction efficiency were thoroughly investigated. Recovery assays for oil samples were spiked at three concentration levels, 50, 100 and 200 mg/kg, and provided recoveries in the 86.3-102.5% range with a relative standard deviation below 3.5%. The intra-day and inter-day precisions for the analysis were less than 3.8%. The proposed method was successfully applied for the determination of synthetic phenolic antioxidants in different oil samples, and satisfactory results were obtained. Thus, the developed method represents a viable alternative for the quality control of synthetic phenolic antioxidant concentrations in edible oils. [ABSTRACT FROM AUTHOR]

Three synthetic phenolic antioxidants, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and tert -butyl hydroquinone (TBHQ), were determined in different edible vegetable oil samples. The analyses were carried out by gas chromatography–mass spectrometry (GC–MS) using microvial insert large volume injection (LVI). Several parameters affecting this sample introduction step, such as temperatures, times and gas flows, were optimised. Quantification was carried out by the matrix-matched calibration method using carvacrol as internal standard, providing quantification limits between 0.08 and 0.10 ng g –1 , depending on the compound. The three phenolic compounds were detected in several of the samples, BHT being the most frequently found. Recovery assays for oil samples spiked at two concentration levels, 2.5 and 10 ng g –1 , provided recoveries in the 86–115% range. [ABSTRACT FROM AUTHOR]

In this paper, a review of the literature on the phenolic compounds with anticancer activity published between 2008 and 2012 is presented. In this overview only phenolic antioxidant compounds that display significant anticancer activity have been described. In the first part of this review, the oxidative and nitrosative stress relation with cancer are described. In the second part, the plant-derived food extracts, containing identified phenolic antioxidants, the phenolic antioxidants isolated from plants and plant-derived food or commercially available and the synthetic ones, along with the type of cancer and cells where they exert anticancer activity, are described and summarized in tables. The principal mechanisms for their anti-proliferative effects were also described. Finally, a critical analysis of the studies and directions for future research are included in the conclusion. [ABSTRACT FROM AUTHOR]

In the present study, an extraction, preconcentration, and determination method has been reported for some synthetic phenolic antioxidants and bisphenol A in honey samples using dispersive liquid-liquid microextraction technique followed by gas chromatography-flame ionization detection. The main factors influencing the extraction efficiency including extractive solvent type and volume as well as the volume of dispersive solvent, salt addition, and pH are evaluated in this study. Under the optimum extraction conditions, limits of detection and quantification for all target analytes were obtained in the ranges of 0.4-4.7 and 1.3-14 ng g, respectively. Enrichment factors and extraction recoveries were in the ranges of 144-186 and 72-93 %, respectively. The method precision was evaluated at 100 ng g of each analyte, and the relative standard deviations were found to be less than 7.6 % for intra-day ( n = 6) and less than 8.3 % for inter-days ( n = 4). The proposed method has been successfully applied to the analysis of different honey samples and two analytes, butylated hydroxytoluene and butylated hydroxyanisole, were determined at nanogram per gram level in one honey sample. [ABSTRACT FROM AUTHOR]

Robust analytical methods were developed for the determination of eight emerging synthetic phenolic antioxidants (SPAs) and three metabolites in sewage sludge, effluent and river water matrices. Accelerated solvent extraction was employed for the extraction of the target analytes from sludge, dichloromethane/hexane = 3:1 (extraction solvent) and 90 °C (extraction temperature) were used after optimization. Silica gel packed column was chosen for the subsequent clean-up procedure for sludge extract. For the water sample analysis, liquid–liquid extraction combined with silica gel clean-up was used. The targets were determined by optimized high performance liquid chromatography–tandem mass spectrometry method in negative electrospray ionization mode. The method quantification limits of the 11 analytes ranged from 0.1 to 23 ng/L, 0.1 to 20 ng/L and 0.1 to 15 ng/g for sewage effluent, river water and sludge matrices, respectively. The total recoveries of the pretreatment varied from 63 to 106%, with relative standard deviations less than 17% for the three matrices at different spiking levels. Nine targets including 2,6-di-tert-butyl-4-methylphenol (BHT), 3,5-di-tert-butyl-4-hydroxybenzaldehyde (BHT-CHO), 2,6-di-tert-butyl-1,4-benzoquinone (BHT-Q), 2,6-di-tert-butyl-4-hydroxy-4-methyl-2,5-cyclohexadienone (BHT-quinol), 3-tert-butyl-4-hydroxyanisole (BHA), 4-tert-octylphenol (4-tOP), 2,2′-methylenebis(6-tert-butyl-4-methylphenol) (AO 2246), 4,4′-butylidenebis(2-(1,1-dimethylethyl)-5-methyl-phenol) (AO 44B25) and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (AO 330) were identified in the collected samples, with concentrations ranging 1.1–2325 ng/g and 0.4–2510 ng/L for sludge and water matrices, respectively. Sewage effluent was considered as a possible contamination source of certain SPA homologues and relative metabolites to the recipient aquatic systems. [ABSTRACT FROM AUTHOR]

Synthetic phenolic antioxidants (SPAs) are widely used as food additives to delay the oxidation rate of oils and oil products. The concentrations and compositions of SPAs in Chinese residents' most popular daily foods and the resulting exposure risk of SPAs are not clear. Therefore, this study collected food samples in 13 food categories (n = 289) from 10 provinces in China. At least one of the SPAs was detected in approximately 99.7% of foodstuffs, and the concentration of ∑SPAs ranged from not detected to 7830 (geometric mean (GM): 296 ng/g wet weight). 2,6-2 tert butyl p-1,4-benzoquinone (BHT-Q) was the main transformation product, but SPAs in food tend to exist in the parent form. A significant difference between food categories was analyzed. The highest GM of ΣSPAs occurred in cereals and cereal products, which was approximately 8 times higher than that in beverages. The estimated daily intakes of ΣSPAs in Chinese preschoolers, school-age children, adults and elderly individuals were 22200, 9970, 7540 and 7700 ng/kg bw/day, respectively. The exposure risks of SPAs decreased with age. This is the first simultaneous analysis of SPAs in multiple provinces and multiple categories of foodstuffs. [Display omitted] • SPAs were measured in 289 food samples in 13 categories from 10 provinces in China. • The concentrations of ∑ 9 SPAs in foods were of n.d.-7830 ng/g wet weight. • The highest GM concentrations of ∑ 9 SPAs were found in cereals and cereal products. • The preschoolers are at the highest risk of exposure to SPAs through food intake. • The first simultaneous analysis of SPAs in multiprovince and multicategory of foods in China. [ABSTRACT FROM AUTHOR]

For the first time, a novel water-contained surfactant-based vortex-assisted microextraction method (WSVAME) was developed for the extraction of two synthetic antioxidants (t-butyl hydroquinone (TBHQ) and butylated hydroxyanisole (BHA)) from edible oil samples. The novel microextraction method is based on the injection of an aqueous solution of non-ionic surfactant, Brij-35, into the oil sample in a conical bottom glass tube to form a cloudy solution. Vortex mixing was applied to accelerate the dispersion process. After extraction and phase separation by centrifugation, the lower sediment phase was directly analyzed by HPLC. The effects of the four experimental parameters including volume and concentration of extraction solvent (aqueous solution of Brij-35), percentage of acetic acid added to the oil sample and vortex time on the extraction efficiency were studied with a full factorial design. The central composite design and multiple linear regression method were applied for the construction of the best polynomial model based on experimental recoveries. The proposed method showed good linearity within the range of 0.200–200 μg mL −1 , the square of correlation coefficient higher than 0.999 and appropriate limit of detection (0.026 and 0.020 μg mL −1 for TBHQ and BHA, respectively), while the precision for inner-day was ≤3.0 ( n = 5) and it was ≤3.80 ( n = 5) for inter-day assay. Under the optimal condition (30 μL of 0.10 mol L −1 Brij-35 solution as extraction solvent and vortex time 1 min), the method was successfully applied for determination of TBHQ and BHA in different commercial edible oil samples. The recoveries in all cases were above 95%, with relative standard deviations below 5%. This approach is considered as a simple, sensitive and environmentally friendly method because of biodegradability of the extraction phase and no use of organic solvent in the extraction procedure. [ABSTRACT FROM AUTHOR]

[Display omitted] • A hierarchical composite ZnO@Carbon foam/PVA cryogel sorbent was developed. • The developed sorbent was applied to extract and enrich parabens and an antioxidant. • The developed sorbent exhibited high extraction efficiency (83.8–99.0%). • The hierarchical composite sorbent was easy to fabricate and was reused 12 times. A hierarchical composite ZnO@Carbon foam/PVA cryogel was fabricated and applied to extract and enrich parabens and synthetic phenolic antioxidant. A hierarchical porous structure was produced by embedding CaCO 3 in the porous PVA cryogel and then removing the CaCO 3 with hydrochloric acid, which generated CO 2 bubbles. The extracted compounds were quantitatively determined by high performance liquid chromatography (HPLC). The ZnO@Carbon foam loading, elution solvent type and volume, sample flow rate, sample volume, ionic strength and sample pH were optimized. The developed method demonstrated linear responses in the range of 0.25–1000.0 μg L−1 for propyl paraben and butyl paraben, 0.50–1000.0 μg L−1 for methyl paraben and 2.00–1000.0 μg L−1 for tert -butylhydroquinone, with R2 above 0.99. For the four analytes, the limits of detection (LOD) and limits of quantification (LOQ) ranged from 0.25 to 2.0 μg L−1 and from 0.75 to 5.0 μg L−1, respectively. The fabricated porous composite sorbent was used to extract and enrich parabens and a synthetic phenolic antioxidant from fruit juice samples. Relative recoveries were in the range of 83.8–99.0% and the RSDs were lower than 6.0%. The enrichment factor of the developed method ranged from 12.5 to 14.9. Low concentrations of tert -butylhydroquinone and butyl paraben were found in some samples at 2.20 and 2.52 μg L−1, respectively. Repeatability was evaluated in terms of intra-day precision and inter-day precision. RSDs were in the range of 2.1–3.0% and 3.5–4.5%, respectively. The developed sorbent was easy to fabricate, and could be reused up to 12 times. [ABSTRACT FROM AUTHOR]

A cloud-point extraction (CPE) method using Tergitol TMN-6 (TMN-6) non-ionic surfactant was developed for the extraction and preconcentration of propyl gallate (PG), tertiary butyl hydroquinone (TBHQ), butylated hydroxyanisole (BHA), and butylated hydroxytoluene (BHT) in edible oils. The optimum conditions of CPE were 1.5 % (v/v) Tergitol TMN-6, 1 % (w/v) NaCl, ultrasound-assist 15 min at 49 KHz, 20 min equilibrated at 45 °C, and centrifugation for 10 min at 3,000 rpm. The surfactant-rich phase was then analyzed by reversed-phase high-performance liquid chromatography (HPLC) with ultraviolet detection at 280 nm, under gradient separation, using methanol and 1.5 % (v/v) acetic acid. Under the study conditions, four synthetic phenolic antioxidants (SPAs) were successfully separated within 24 min. Limits of detection in the studied edible oils were in the range of 1.6 to 9.0 ng mL. The high recoveries of the spiked edible oils were obtained in the range 90-98 %. The CPE method has been shown to be a potentially useful methodology for the preconcentration of the target analytes, with a preconcentration factor of 25. This method was compared with cloud point extraction (using Triton X-114) and liquid-liquid extraction (using methanol). [ABSTRACT FROM AUTHOR]

Abstract: Antioxidant-active packaging is a promising technology for food protection. In this study Poly lactic acid (PLA) granules containing 2% (w/w) synthetic phenolic antioxidants (SPA) including butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate (PG), and tert-butylhydroquinone (TBHQ) were extruded in a pilot plant extruder. SPA''s release from PLA-SPA films into 10%, 50% and 95% ethanol at 20 °C and 40 °C was regularly measured by HPLC system for 60 days. TBHQ partially decomposed to 2-tert-butyl-1,4-benzoquinone (TBBQ) both during extrusion process and release tests under all conditions. Diffusion of the SPAs from PLA to simulants showed a Fick''s behavior with diffusion coefficient (D) value between 10−8 and 10−11 cm2 s−1 with 0–100% of release. Faster and higher release of SPAs occurred at 40 °C according to Arrhenius law. PG and BHT had respectively the highest and lowest release rate in all simulants due to their different molecular properties such as polarity, Log P and molecular volume. Higher ethanol content of simulant and temperature both influenced the PLA hydrolysis during release study; at 40 °C, all PLA films in contact with 50% ethanol turned opaque and fragile. Total and fast release of SPA into 95% ethanol at 40 °C and their small release into 10% ethanol at 40 °C and 20 °C suggests using PLA-SPA active packaging for oils, oily foods and some milk products which are highly sensitive to oxidation to ensure higher food quality. Finally, PLA-antioxidant active packaging approach also permits to reduce the amounts of directly added antioxidants in foods to provide safer foods. [Copyright &y& Elsevier]

Abstract: A simple, rapid and sensitive sample pretreatment technique, termed dispersive liquid–liquid microextraction (DLLME), was developed as an extraction methodology to determine two synthetic phenolic antioxidants (SPAs), butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT), in various fruit juice samples prior to high performance liquid chromatography (HPLC). The extraction method is based on replacing the extraction solvent in the ordinary DLLME, namely the chlorinated organic solvent, with low-density organic solvents such as hexane, ethyl acetate, octanol and 2-ethyl-1-hexanol in the ternary component solvent (aqueous solution:extracting solvent:disperser solvent) system. Several factors affecting the microextraction efficiency, such as type and volume of extraction and dispersive solvents, pH of the sample solution, extraction time, ionic strength and extraction temperature, were investigated. Under the optimum conditions, the method yielded a linear calibration curve ranging from 10 to 2500μgL−1 for BHA and 2 to 2500μgL−1 for BHT, with determination coefficients (R 2) varying from 0.9993 to 0.9989. Enrichment factors for BHA and BHT were 208 and 203, and limits of detection were 2.5 and 0.9μgL−1, respectively. The relative standard deviation percent (RSD%) for the extraction and determination at 10 and 100μgL−1 levels of target antioxidants was less than 4.7% (n =7). Finally, the designed method was successfully applied for the preconcentration and determination of the studied SPAs in different fruit juice samples, and satisfactory results were obtained. [Copyright &y& Elsevier]

A spectrofluorimetric method is presented for the determination of 2 synthetic phenolic antioxidants (SPAs), butylated hydroxyanisole (BHA), and propyl gallate (PG) in foodstuffs. The proposed method is based on the derivatization of SPAs with 4-chloro-7-nitrobenzofurazan (NBD-Cl) in phosphate buffer of pH 9.0 to yield a highly fluorescent brown product. The optimum experimental conditions have been studied carefully. Linear calibration curves were obtained over the concentration range of 0.20 to 40 μg mL−1 for BHA, and 0.80 to 50 μg mL−1 for PG, using NBD-Cl reagent. The detection limits were 18 ng mL−1 for BHA, 55 ng mL−1 for PG. Intra-day and inter-day relative standard deviations at 3 different concentrations were determined. The high recovery values indicate the accuracy of the proposed methods, and low relative standard deviation values indicate good precision. The results presented in this report show that the applied spectrofluorimetric method is acceptable for the determination of the 2 SPAs in the foodstuffs. Other SPAs, tertiary butyl hydroquinone and butylated hydroxytoluene in foodstuffs do not interfere with the proposed method. Practical Applications: In this spectrofluorimetric method, NBD-Cl as a derivation agent is used to detect synthetic phenolic antioxidants. The method specificity has been greatly improved; there was no interference from other commonly used phenolic substances. [ABSTRACT FROM AUTHOR]

Abstract: Synthetic phenolic antioxidants (SPAs) including BHA, BHT, PG and TBHQ were added (1%, w/w) to a poly (lactic acid) (PLA) film. SPA addition had no significant effect on the glass transition and melting temperatures of the PLA film but reduced the crystallinity about 26% and the crystallization temperature by 6–12°C from the value of 107°C found for pure PLA film. Young''s modulus of PLA film was reduced about 12% by BHA and about 17% by PG and TBHQ. The tensile strength of PLA film also was influenced by BHA, PG and TBHQ. Water vapor permeability of PLA film was not changed by addition of SPAs and PLA oxygen permeability only increased by 30% on BHT addition. No significant changes were observed for surface energy and surface hydrophilicity of PLA films. PLA film microstructures investigated by Atomic force microscopy were significantly changed in term of roughness parameters (R a and R q). The results showed that the addition of SPAs in PLA for the creation of active packaging had no negative effect on PLA technical properties. [Copyright &y& Elsevier]