Easy and Inexpensive Method for Multiclass Analysis of 41 Food Contact Related Contaminants in Fatty Food by Liquid Chromatography-Tandem Mass Spectrometry

Concentrations of per- and polyfluoroalkyl substances in vegetables from Sydney and Newcastle, Australia

BACKGROUND

This study investigated per- and polyfluoroalkyl substances (PFASs) in 53 fruit and vegetable samples collected from a local wholesale and retail market in Sydney and a local supermarket in Newcastle. As there is limited information about PFAS levels in vegetables on the market, this study aimed to fill this gap and assess potential risks for humans through consumption of these vegetables.

METHODS

QuEChERS extraction - a solid-phase extraction method, a portmanteau word formed from 'quick, easy, cheap, effective, rugged and safe' - followed by enhanced matrix removal-lipid cleaning and liquid chromatography-tandem mass spectrometry analysis were used to detect 30 PFASs in vegetables.

RESULTS

PFOA was detected in 7 out of the 53 samples, with concentrations of 0.038-1.996 ng g-1 fresh weight; PFOS was detected in 2 samples only, with concentrations ranging from 0.132 to 0.911 ng g-1 fresh weight. PFHxS was not detected in any sample in this study. PFOA and PFOS concentrations measured in vegetables in this study constituted daily intake of 2.03 ng kg-1 body weight (BW) and 1.98 ng kg-1 BW, respectively, according to recommended daily vegetable intake and BW data from the Australian Bureau of Statistics. The most sensitive population group is girls of 4-8 years of age. These estimated exposure levels represent up to 1.3% of the tolerable daily intake for PFOA (160 ng kg-1 BW) and 9.9% for PFOS (20 ng kg-1 BW) according to Food Standards Australia New Zealand. Consumption of the vegetables from the study locations poses a marginal risk to human health. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

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.

A Novel and Highly Efficient Microextraction Method for the Determination of Aflatoxin Precursor Averantin in Fatty Grain Samples

Averantin (AVN) is an important aflatoxin biosynthetic precursor and has been listed in the screening range of mycotoxins. Herein, a novel ionic liquid-based one-, two-, and three-phase transition microextraction (IL-OTTPTME) method was combined with high-performance liquid chromatography for the extraction and determination of AVN in fatty grain samples. The formation of a homogeneous solution and three-phase system during the IL-OTTPTME process allowed both efficient extraction and coextracted lipid cleanup. Density functional theory calculations and distribution coefficient determination results demonstrated that AVN extraction by IL mainly occurred through hydrogen-bond and π-π interactions. Under optimized conditions, the LOD and LOQ of the proposed method were 0.5 and 1.5 ng/g, respectively. Finally, the method was used to determine AVN in several grains with different fat contents, achieving satisfactory relative recoveries (86.0-107.8%) and RSDs (1.2-6.2%, n = 3).

Research Progress of Perfluoroalkyl Substances in Edible Oil-A Review

Perfluoroalkyl substances (PFASs) have been widely used in different types of consumer and industrial applications such as surfactants, household cleaning products, textiles, carpets, cosmetics, firefighting foams, and food packaging because of their good stability and special physicochemical properties of hydrophobicity, oleophobicity, high temperature resistance, etc. Meanwhile, PFASs are considered an emerging organic pollutant due to their persistence and potential toxicity to human health. PFASs occur in edible oil, an important component of the global diet, mainly in three ways: raw material contamination, process contamination, and migration from oil contact materials. Thus, the occurrence of PFAS in edible oils has drawn more and more attention in recent years. In this work, the pertinent literature of the last two decades from the Web of Science database was researched. This review systematically addressed the potential sources, the contamination levels, and the progress of the determination of PFASs in edible oil. It aims to provide a relatively whole profile of PFASs in edible oil, render assistance to minimise human exposure to PFASs, and standardise the detection methods of perfluoroalkyl substances in edible oil.

Fluorescence Signal Amplification: Red Carbon Dots@SiO2-Induced Ultra-sensitive Immunoassay for Diethyl Phthalate

Carbon dots as new nanomaterials, have been widely used in rapid detection because of their nondestructive, real-time detection characteristics. Improving the sensitivity and selectivity of the method in complex real samples is new challenge and requirement for sensing technology. Here, we report an ultrasensitive fluorescence immunoassay (FIA) for trace diethyl phthalate (DEP) using red carbon dots@SiO₂ (R-CDs@SiO₂) as tags. SiO₂ as a nanocarrier can effectively improve the bio-functionalization and utilization rate of carbon dots. Moreover, several R-CDs embedded in SiO₂ nanospheres can magnify the fluorescence signal and improve sensitivity. R-CDs@SiO₂ conjugate anti-DEP antibody (Ab) as fluorescent immunosensor, which can specifically recognize DEP. Under optimization conditions, the detection limit (LOD) of this FIA was calculated as 0.0011 ng/mL. In addition, the recoveries of this established FIA ranged from 96.8 to 108.5%, showing satisfactory accuracy. Compared with GC-MS/MS (LOD µg/mL), the sensitivity of the FIA was significantly improved. As a result, the FIA developed using R-CDs@SiO₂ as tags has a high potential for determining trace DEP.

Non-targeted analysis with liquid chromatography - high resolution mass spectrometry for the identification of food packaging migrants

Potential contamination of food with chemicals migrating from food packaging is an important, yet under-investigated area of food safety. In this study, we examined chemicals migrating from common paper-based food packaging: pizza boxes and pizza box liners, butcher paper and liquid egg containers. Migration tests were conducted with a food simulant for 10 days, and migrated chemicals were identified with liquid chromatography (LC) - high resolution mass spectrometry (HRMS) with mass error < 3 ppm. HRMS identification was based on spectra and/or structure matching against commercial databases (MzCloud, ChemSpider, and Extractable and Leachable high resolution accurate mass (HRAM) database). Following HRMS identification, orthogonal LC retention information was utilized to further refine the data and reduce false positive findings. A model for calculating retention times (t_R) based on octanol-water partition coefficient (log K_ow) values was evaluated and applied for HRMS data refining. Using this approach, 153 migrated chemicals were identified, of which five were further confirmed with reference analytical standards. Additionally, amounts of bisphenol A and bisphenol S, the chemicals of toxicological concerns, were measured at the levels below the established regulatory limits for migration, indicating no/low risk to consumer's health. This study demonstrated the utility of LC-HRMS for confident identification of food packaging migrants.

Occurrence of selected per- and polyfluorinated alkyl substances (PFASs) in food available on the European market - A review on levels and human exposure assessment

Per- and polyfluorinated alkyl substances (PFASs) are considered emerging persistent organic pollutants, which are chemically, thermally, and biologically stable, or degrade to persistent end products. Dietary intake is considered as one of the main human exposure pathways of these chemicals and, having entered the human body, PFASs are not metabolised and accumulate in tissues, while their toxicological properties may cause various health problems. Several studies on the occurrence of PFASs in various food types have been conducted, including the assessment of dietary exposure. The most important sources were fish, meat, eggs, fruits, and vegetables. Fruits and vegetables recently showed relatively high levels of PFASs, and have become a more significant source of PFASs than meat. In 2020, the European Food Safety Authority (EFSA) published an opinion, setting the tolerable weekly intake (TWI) of 4.4 ng kg-1 b.w. for the sum of perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexanesulphonic acid (PFHxS), and perfluorooctanesulphonic acid (PFOS). The emphasis in this paper is on the systematization of available information on the distribution of PFASs and their levels in different food, with a special interest in data from the Europe. The current legislation and estimated dietary intakes by the general population are described. While the available information on tolerably daily intakes estimated in a number of European countries often exceeds the newly established EFSA TWI, a critical evaluation of performance characteristics of the reviewed analytical methodologies revealed the insufficient sensitivity of quantification procedures for accurate risk assessment according to the guidelines proposed by EFSA.

Exposure estimates of phthalates and DINCH from foods and personal care products in comparison with biomonitoring data in 24-hour urine from the Norwegian EuroMix biomonitoring study

Phthalates are diesters of phthalic acid and have been widely used as plasticizers in polyvinyl chloride (PVC) plastics. Phthalates are also used as excipients in pharmaceuticals and personal care products (PCPs). Phthalates can migrate from the plastic into the air, water and food, and humans can be exposed via multiple pathways such as dermal, oral and inhalation. There is evidence that phthalates can induce reproductive and developmental toxicity not only in experimental animals but also in humans through disruption of estrogenic activity. The aim of this study was to collect concentration data on five phthalates in foods and PCPs from the scientific literature and combine these with food consumption data and PCP use frequency data from the EuroMix biomonitoring (BM) study in order to assess exposure. Probabilistic exposure assessments of phthalates were performed from foods and PCPs. Due to the very limited data available in the literature for DINCH, an exposure assessment was not carried out for this compound. The food groups with the highest contribution to phthalates exposure were: beverages, dairy, bread and meat products. The exposure estimates were compared with the measured phthalate metabolite levels from 24-hour urine samples. Regarding the oral route, measured phthalate exposure was between the lower bound (LB) and medium bound (MB) estimated exposure for all phthalates, except for DEP. The measured exposure from urine correlated with the estimated exposure from food for DEHP and DBP, while for BBP and DEP it correlated with the exposure estimates from PCPs. There were no significant differences between the BM data and the estimated exposure, except for DINP for males (p = 0.01). The LB and MB phthalate exposures estimated from foods and PCPs and the measured exposure from the urine were considerably lower than their respective tolerable daily intake (TDI) values established by the European Food Safety Authority (EFSA) and the World Health Organization (WHO). For the upper bound (UB), the exposure estimates are approximately double the TDI; however, this is regarded as a worst-case estimate and has low correlation with the measured exposure.

Screening of chemicals migrating from plastic food contact materials for oven and microwave applications by liquid and gas chromatography - Orbitrap mass spectrometry

Contamination of food with chemicals migrating from food contact materials (FCMs) is an important area of food safety. This study was aimed to investigate migration of chemicals from plastic FCMs used for microwave and conventional oven heating. Migration tests were conducted for samples of microwave trays, microwave oven bags, and oven bags. GC- and LC-Orbitrap mass spectrometry (MS) was used for non-targeted screening and identification of chemicals with mass error <5 ppm. A non-targeted identification approach was validated with isotopically labeled chemicals to establish acceptable criteria for identification of migrated compounds. A total of 74 migrated compounds were tentatively identified: 24 chemicals by GC-Orbitrap MS with electron ionization (EI), plus 35 and 19 by LC-Orbitrap MS electrospray ionization (ESI) with positive and negative polarities, respectively. Four migrated chemicals were identified by more than one instrumental analysis. Both intentionally added substances (IAS), i.e. additives used in the production of polymeric materials and plastics, and non-intentionally added substances (NIAS), i.e. derivatives and degradation/oxidation products of IAS, were identified among the migrated chemicals. The levels of 25 migrated chemicals were significantly different (p < 0.05) between microwave treatments and conventional oven treatments, where 20 migrants had higher levels for microwave compared with 5 for conventional oven treatments. For several identified chemicals, no previous reports on their migration from FCMs were found.

A fast SALLE GC-MS/MS multi-analyte method for the determination of 75 food packaging substances in food simulants

A simple and fast method was developed for the simultaneous determination of 75 plastic food contact material (FCM) in liquid food simulants, at levels of a few ng g^-1. The method employs an optimised salt-assisted liquid-liquid extraction for all EU-regulated ethanol/H₂O food simulants, in the presence of 10% NaCl (simulants A and C) or 5% NaCl (simulant D1), and dichloromethane as the extracting solvent. Gas chromatography with triple-quad MS operating in multiple reaction monitoring acquisition was used, applying isotope dilution with selected deuterated compounds. Adequate sensitivity was demonstrated for all analytes. The results also showed sufficient accuracy for the majority of substances, with recoveries of 70-120% and repeatability (expressed as relative standard deviations, RSDs) smaller than 15%. The method was applied to the analysis of FCM multilayer items after undergoing migration testing according to the specifications of the current EU legislation in force.

New deep eutectic solvent based superparamagnetic nanofluid for determination of perfluoroalkyl substances in edible oils

Perfluoroalkyl substances (PFASs) have been identified as global pollutants and raise considerable food safety concerns. However, the development of an analytical method with satisfied pretreatment performance for PFASs with varying alkyl chain length in the fatty samples remains a challenge. We describe herein the preparation of superparamagnetic nanofluid, based on a new choline chloride/1-(o-tolyl)biguanide deep eutectic solvent (DES) system, for direct extraction of perfluoroalkyl carboxylic acids from edible oils. Target PFASs, especially the short-chain one, all possessed high recoveries (90-109% with intra-day and inter-day precision below 10%). This was achieved by adjusting the constituent ratio of DES for balancing the anion-exchange (electrostatic) interactions and hydrogen-bond interactions. Employing the prepared nanofluid in magnetic microextraction, followed by high-resolution mass spectrum analysis, resulted in a rapid (15 min for pretreatment), simple, sensitive (detection limit: 0.3-1.6 pg g^-1), and efficient method for the enrichment and determination of trace PFASs. Furthermore, the introducing of N-H⋯F weak force increased the pretreatment selectivity to effectively reduce the matrix effect. At the end of the study, the proposed methodology was successfully applied to the analysis of target analytes in real samples.

Development and validation of a multi-analyte GC-MS method for the determination of 84 substances from plastic food contact materials

Chemical substances shall not migrate from food contact materials (FCM) at levels that are potentially harmful for the consumers. Each of the current analytical methods applied to verify the migration of substances from FCM covers only one or few substances. There is a very limited number of publications on the development of analytical methods allowing the simultaneous determination of several classes of FCM substances, and almost none of them reported methods entirely dedicated to the ones in the positive list of Commission Regulation (EU) No. 10/2011 for plastic FCMs. Therefore, a simple, sensitive and reliable multi-analyte method was developed for the analysis of FCM substances in food simulants. It employs an optimised liquid-liquid extraction with dichloromethane as extraction solvent in the presence of 10% m/v NaCl, followed by quantitative analysis with gas chromatography coupled to mass spectrometry (GC-MS). A combination of total ion chromatograms (TICs) and extracted ion chromatograms (EICs) was used. The optimisation and validation of the method have been carried out according to current international guidelines. Adequate sensitivity was demonstrated in the selected concentration ranges for most of the analytes, with limits of quantification (LOQs) at least three times lower than the legislative limit, when existing. The results showed that the method is sufficiently accurate for the majority of substances, with recoveries between 70 and 115% and relative standard deviations (RSDs) smaller than 20% at three concentration levels. The method was applied to the analysis of some FCM multilayers. The method allows, for the first time, the simultaneous quantification of 84 FCM substances in two of the official food simulants (A and C) at levels of a few ng g⁻¹.