Chemometric evaluation of inorganic and organic parameters found in Rosaceae plants proposed as food supplements.

This study discusses the organic and inorganic composition of young inflorescence tissues of seven medical plants from the Prunus, Malus, and Chaenomeles families. These plants contain bioactive compounds with antioxidant and cytotoxic properties, and the study determined 29 elements, including essential and potentially harmful ones, established correlations with inorganic and organic compounds, as well as antioxidative and cytotoxic effects. The elemental patterns show that the plants contribute beneficial essential elements to the human diet. The levels of toxic elements in the plants are within safe limits set by the World Health Organization for medicinal herbs. The results confirmed genus- and species-specific uptake and accumulation. Positive correlations between d-block metals and alkaline earth metals in the inflorescences were found alongside statistically significant differences between analyte categories regarding macro-, micro- and trace elements and bioactive compounds. These correlations need to be considered when giving dietary recommendations or advice for uses as home-remedies.

Preliminary Study of Pepper Types Based on Multielement Content Combined with Chemometrics.

Different types of pepper (Piper nigrum L.) and cayenne pepper (Capsicum annuum L.) are widely used spices that exhibit therapeutic properties in addition to nutritional properties. In order to characterize these foods in further detail, the content of macro- (Ca, K, Mg, Na) and microelements (Ag, Al, As, Ba, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, Li, Mn, Mo, Ni, Pb, Rb, Se, Sr, Te, Tl, V and Zn) of four pepper types was determined via inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted digestion using nitric acid and hydrogen peroxide. The obtained results were then evaluated using chemometric methods. The content of macroelements and microelements lies in the expected ranges for such spices but differs significantly between different types. The content of macro- and microelements is characteristic for pepper types originating from different plant species, but also based on further processing. Whilst green and black pepper are similar to each other, clearly diverse patterns are obtained for white pepper (different processing method) and cayenne pepper (different plant species).

Preliminary trends over ten years of persistent organic pollutants in air - Comparison of two sets of data in the same countries.

In two series of ambient air measurement campaigns to support the implementation of the global monitoring plan (GMP) component of the Stockholm Convention on Persistent Organic Pollutants (POPs), passive air samplers (PAS) using polyurethane foams were implemented by the United Nations Environment Programme (UNEP). With the same laboratories responsible for the chemical analyses of the different groups of POPs, a total of 423 PUFs were analyzed for organochlorine pesticides (OCPs) including hexachlorobenzene (HCB) and polychlorinated biphenyls (PCB); 242 for dioxin-like POPs. For trend analysis, to compare amounts of POPs in the PUFs during the first phase in 2010/2011 and the second phase from 2017 to 2019, only results were assessed that were generated in the same country and for the same POP in both campaigns. Finally, there were 194 PUFs available for OCPs (GMP1 = 67 and GMP2 = 127), 297 for PCB (GMP1 = 103, GMP2 = 194), 158 for polychlorinated dibenzodioxins and polychlorinated dibenzofurans (PCDD, PCDF) (GMP1 = 39, GMP2 = 119), and 153 for dl-PCB (GMP1 = 34, GMP2 = 119). Indicator PCB and dioxin-like POPs were quantified in all countries at all times; decreases of about 30% based on median values were determined. A 50% increase was found for HCB. By scale, DDT remained with the highest values, although more than 60% decrease was found; mainly due to smaller values in the Pacific Islands region. Our assessment showed that on relative scale - per PUF - trend analysis was achieved and that such approach should be undertaken at regular intervals, not necessarily on an annual basis.

Dioxin-like POPs in national samples from global monitoring plan projects (2017-2019).

The global monitoring plan (GMP) established under the Stockholm Convention on Persistent Organic Pollutants (POPs) had defined ambient air, human milk or blood, and water as core matrices to be analyzed and assessed for spatial and temporal distribution. Within projects coordinated by the United Nations Environment Programme (UNEP), developing countries were offered to have other matrices analyzed for dioxin-like POPs (dl-POPs) in experienced laboratories. Subsequently, 185 samples from 27 countries located in Africa, Asia, and Latin America were collected during 2018-2019 and analyzed for polychlorinated dibenzodioxins (PCDD), dibenzofurans (PCDF), and biphenyls (PCB). Using the WHO2005 toxic equivalency approach (TEQ), the amounts of dl-POPs found were low (<1 pg TEQ/g); however, singular samples had higher values; e.g., egg from Morocco, fish from Argentina or Tunisia; soil and sediment samples. Results showed that the matrix, abiotic or biota, had more impact on the TEQ pattern than the geographic location. Independent of the location and across all samples, dl-PCB in (shell)fish and beef samples had a contribution of 75% to the total TEQ; milk (63%), chicken (52%), and butter (50.2%) more than 50%. Sediment (57% and 32%) and soil (40% and 36%)) samples were dominated by PCDD and PCDF, respectively; therein, dl-PCB had shares of 11% and 24%. Egg samples (N = 27) did not follow the general biota pattern and had 21% of the TEQ from the PCDD, 45% from PCDF, and 34% from dl-PCB; thus, indicating that abiotic matrices such as soil or other material may have an impact.

Assessment of the per- and polyfluoroalkyl substances analysis under the Stockholm Convention - 2018/2019.

The comparability of laboratories for the analysis of per- and polyfluoroalkyl substances (PFAS) was assessed in the fourth round (2018/2019) of a series of interlaboratory assessments coordinated by the United Nations Environment Programme (UNEP) in support of the Stockholm Convention quality assurance activities as to persistent organic pollutants (POPs) laboratories reporting data under this Convention. The participating laboratories were asked to analyse PFAS concentrations in a test solution of the target compounds, in the four core matrices of the global monitoring plan (GMP), human milk, human plasma, an air extract, and water, and in a sediment and a fish matrix. 39 participating laboratories submitted PFAS data for one or more test materials. The majority of the participating laboratories originated from the Asia-Pacific region, and from the 'Western European and other groups' (WEOG). Only one laboratory from the group 'Latin America and Caribbean' (GRULAC), and two from the Central and Eastern Europe (CEE) region submitted results. None of the African laboratories submitted data. The coefficients of variation (CVs) varied from 7% to 24% (mean 14%) for the test solution. Mean CVs for all matrices, except for the human plasma test material (18%), were above the satisfactory limit of 25%. The highest mean CV was found for human milk (61%). In total 1457 z-scores were assigned of which 64% were satisfactory (|z| < 2). Instrumentation used was mainly high-performance liquid chromatography (HPLC), in combination with various mass spectrometric (MS) techniques, in most cases tandem MS (MS/MS). Additional PFAS beyond perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), which are listed at the Stockholm Convention POPs list, as well as water as a matrix for PFAS only and human plasma were added as a service for the laboratories.

Persistent organic pollutants in human milk from primiparae - correlations, global, regional, and national time-trends.

Human breast milk reflects body burden of chemicals and has been used for exposure assessment to estimate risks of humans from pollutants. Harmonized protocols for sampling and analysis of persistent organic pollutants (POPs) have become widely available after the entry-into-force of the Stockholm Convention on POPs and activities coordinated by the United Nations Environment Programme (UNEP). These protocols promote the generation of national pools consisting of breast milk from first mothers directed to assess at national level but have not been assessed comprehensively. Early surveys date back to the mid-1980s, but the majority of the pools and high numbers of POPs analytes were available after the year 2000. Our assessment of pools from 90 countries for 29 POPs showed declining time trends for almost all POPs and significant differences between all 5-year time periods. However, in general, the most recent data from samples collected between 2015 and 2019, were no longer different from the period immediately prior. The strongest declines were seen for POPs that have already been measured for more than 30 years, i.e., dioxin-like POPs and polychlorinated biphenyls (PCB). For certain initial and newly listed POPs, such as aldrin, endrin, mirex, toxaphene, α-HCH, chlordecone, endosulfan, pentachlorobenzene, hexachlorobutadiene, decabromo diphenyl ether, hexabromobiphenyl 153, and perfluorohexane sulfonate, the median values in pools were always zero, and some of them were never quantified in these human milk pools. Since these POPs may be present at national level, we recommend including all listed POPs into surveys related to the Stockholm Convention.

Perfluoroalkane substances in national samples from global monitoring plan projects (2017-2019).

The global monitoring plan (GMP) established under the Stockholm Convention on Persistent Organic Pollutants (POPs) had defined ambient air, human milk or blood, and water as core matrices to be analyzed and assessed for spatial and temporal distribution. Within projects coordinated by the United Nations Environment Programme (UNEP), developing countries were offered to have other matrices analyzed for perfluoroalkane substances (PFAS) in one experienced laboratory. A total of 266 samples from 26 countries located in Africa, Asia, and Latin America were collected during 2018-2019 and analyzed for 15 PFAS. The limits of quantification were 6.2 pg/g fresh weight for most PFAS. The statistical assessment of 262 samples, four were excluded due to extreme values, showed that across abiotic and biota samples, perfluorooctane sulfonic acid (PFOS) had the highest detection frequency (80%) and the highest median value (19.2 pg/g), followed by perfluorooctanoic acid (PFOA) with 73% and a median value of 7.67 pg/g. Among the matrices, water (55%), sediment (49%) and fish (44%) had the most complex pattern, i.e., number of PFAS quantified. Dairy products and chicken meat had less PFAS present. From the 137 foods, fish, meat, eggs, analyzed in this study, only two fish samples would exceed one of the limit values proposed by the European Commission. To assess human exposure, we suggest including dairy products and drinking water since selective and sensitive methods would allow quantification of the four proposed PFAS.

POPs monitoring in Mongolia - Core matrices.

Persistent organic pollutants (POPs) are of global concern due to their negative effects on humans and the environment, and globally are regulated in the Stockholm Convention on POPs. The present study had Mongolia as a partner in a multinational project funded and coordinated by the United Nations Environment Programme with the aim to monitor POPs in core media, including air (with passive samplers), water, and a pooled human milk sample. Project implementation and all sampling were undertaken by the Institute of Chemistry and Chemical Technology whereas POPs analysis was performed in laboratories abroad. Brominated and chlorinated POPs were analyzed by gas chromatography/mass spectrometry, perfluorinated compounds (PFAS) and isomers of hexabromocyclododecane (HBCD) by liquid chromatography/mass spectrometry. The monitoring results found very low concentrations of PFAS in river water. Toxic equivalents (TEQs) for PCDD/PCDF were low in air and in human samples but had a relatively higher presence of TEQ from dioxin-like PCB than in other countries. With respect to chlorinated POPs, drins, chlordanes, DDTs, heptachlors, and mirex were very low in air and human milk. Elevated levels were found for polychlorinated biphenyls (PCB), hexachlorobenzene (HCB), hexachlorocyclohexanes (HCHs), pentachlorobenzene (PeCBz), and HBCD in air with extreme values for hexachlorobutadiene. The abundance of HCHs and HCB was confirmed in the human milk sample but not for PCB, PeCBz or HBCD. Short-chain chlorinated paraffins (170 ng/g lipid) were the highest among all human milk pools. It is recommended to continue POPs monitoring in the future, especially for those where high concentrations were found.

Global interlaboratory assessments on PCBs, organochlorine pesticides and brominated flame retardants in various environmental matrices 2017/2019.

In support of the United Nations Environment Programme (UNEP) global monitoring plan under the Stockholm Convention contributing laboratories were offered to take part in a series of interlaboratory assessments on persistent organic pollutants (POPs). The results of two rounds of these assessments are reported. The target compounds were polychlorinated biphenyls, organochlorine pesticides, polybrominated diphenylethers, one polybrominated biphenyl and hexabromocyclododecane diastereomers. The matrices distributed were a test solution, fish, sediment, human milk, and air extracts. The number of participants in each round was well over 100, showing the interest of laboratories worldwide. The results showed that many laboratories still struggle to obtain acceptable standard deviations of around 25% for their determinations. In particular for organochlorine pesticides serious improvement in quality is required. Acceptable results were obtained for the air extracts and for the determination of polybrominated diphenylethers in various matrices.

Assessment of four rounds of interlaboratory tests within the UNEP-coordinated POPs projects.

Since 2005, the United Nations Environment Programme (UNEP) has supported developing countries with capacity building, including on-site training courses and provision on laboratory materials and consumables, and analysis of samples from Africa, Asia-Pacific and Latin America and the Caribbean (GRULAC) in designated expert laboratories. In order to check the performance of laboratories analyzing persistent organic pollutants (POPs) and giving trust into chemical analytical results, four rounds of interlaboratory assessments (ILs) were organized between 2010 and 2019. These were open to all POPs laboratories. In total, 41 575 z-scores, as indicators of performance, were generated in these four ILs; of these, 8 912 were from laboratories in countries supported by UNEP projects and 3 923 were from expert laboratories; these together constitute 31% of the total. 69% of all z-scores came from laboratories not participating in the UNEP projects, especially from China, who recognized the importance of such exercises for quality control at an early stage. The results showed that POPs analytical capacity has increased over the years, but some gaps could not be closed especially not when LC-MS/MS equipment is essential such as for PFAS and congener-specific HBCD. Use of mass spectrometers provides better results than ECD instruments due to the broad spectrum of organochlorine pesticides to be analyzed under the Stockholm Convention. The main conclusion for all laboratories is that interlaboratory assessments provide important and objective snapshots of performance for the laboratories themselves and for external clients. The methods used in any interlaboratory testing should be the same as during routine analysis between such tests.

Influence of land use type and urbanization level on the distribution of pharmaceuticals and personal care products and risk assessment in Beiyun River, China.

Influence of land use type and urbanization level on the distribution of pharmaceuticals and personal care products (PPCPs) from the developed regions of Beijing-Tianjin-Hebei in the northern China was evaluated. The seasonal and spatial variations of the 22 target PPCPs were analyzed in the 63 sampling sites along the whole Beiyun River Basin. Results showed that the total PPCPs concentration had a wide variation range, from 132 ng L-1 to 25474 ng L-1. Spatial interpolation analysis showed that agricultural land presented higher PPCPs contamination level than build-up land (p < 0.05) and the concentration was negatively correlated with urbanization level. Source apportionment showed the untreated sewage source contributed to 34%-53% of the PPCPs burden in the Beiyun River. Risk assessment indicated that diethyltoluamide, carbamazepine, octocrylene, gemfibrozil and triclocarban had high risks (RQ > 1), and small tributaries had the highest mixed risk (MRQ = 34). Species sensitivity distribution combined with the safety threshold method showed that PPCPs would have potential risk on aquatic organisms even at very low concentrations and triclocarban posed the highest risk in the Beiyun River.

Air monitoring with passive samplers for dioxin-like persistent organic pollutants in developing countries (2017-2019).

As part of the global monitoring plan on persistent organic pollutants (GMP) under the Stockholm Convention passive air samplers equipped with polyurethane foam disks (PUFs) were applied to monitor dioxin-like POPs. For sampling, toluene-pretreated PUFs were exposed for three months during two years. Chemical analysis was performed in one accredited expert laboratory using internationally accepted methods; for comparison, all results were normalized to one PUF and 3 month exposure. Total TEQs, using WHO2005-TEFs, were lowest in the Pacific Islands countries (PAC) and had similar mean values in Africa (16.8 pg TEQ/PUF), Asia (16.9 pg TEQ/PUF), and Latin American and Caribbean countries (GRULAC, 13.3 pg TEQ/PUF). Using median values, Asia (13.4 pg TEQ/PUF) and GRULAC (13.1 pg TEQ/PUF) had higher amounts than Africa (6.1 pg TEQ/PUF) and PAC (2.1 pg TEQ/PUF). The contribution of PCDD/PCDF to the total TEQ was 2-3-times higher than from the dl-PCB. Mono-ortho PCB did not play a role in any of the samples. The previous 40 samples during 2010/2011 and the present 195 samples from 2017/2018 did not show a statistical difference (p value = 0.3), only for GRULAC, a downward trend was identified. It is recommended combining 4 PUFs to 'annual' samples.

Interlaboratory assessments for dioxin-like POPs (2016/2017 and 2018/2019).

In the two rounds of the UNEP-coordinated 'Biennial interlaboratory assessments of POPs laboratories, which were implemented in 2016/2017 and 2018/2019, 56 and 46 laboratories submitted results for dioxin-like persistent organic pollutants (dl-POPs). Test matrices consisted of solutions of analytical standards and naturally contaminated sediment, air extract, fish and human milk. Performance assessment using z-scores so that satisfactory performance corresponded to 2 z = ±25%, which is recommended for laboratories submitting data to the global monitoring plan of the Stockholm Convention on POPs. Participation has shown that analytical capacity for analyzing dl-POPs exist in all UN regions; however, in Africa and Central and Eastern European countries capacities are (very) limited; in Latin America capacity is increasing. The presence of dioxin laboratories is not limited to industrialized or OECD countries but also present in developing countries such as China, Brazil, Egypt, Thailand, or Vietnam. Laboratories using established methods based on gas chromatographs coupled to high-resolution mass spectrometers (sector field instruments only) by far had the best results. Among the test samples, human milk and especially fish in the last round posed severe problems to all laboratories so that performance must improve, especially in foodstuffs at (very) low concentrations.

Air monitoring with passive samplers for perfluoroalkane substances in developing countries (2017-2019).

To support the global monitoring plan on persistent organic pollutants (GMP) under the Stockholm Convention, 41 countries have exposed passive air samplers equipped with polyurethane foam disks (PUFs) to monitor perfluoroalkane substances (PFAS). The recommended procedure had PUFs exposed for three months during two years; analysis was performed in one expert laboratory to generate harmonized results. Chemical analysis using Soxhlet extraction with methanol or a 60:40 MTBE:methanol mixture, solid-phase extraction and UPLC/MSMS detection posed challenges as to matrix interference and sensitivity. Single PUFs as quarterly samples and combination of up to 4 PUFs as annual samples were analyzed; all concentrations were normalized to one PUF and 3 months exposure. Exceptionally high values (up to 36 000 pg SPFOS/PUF) were observed in nine samples from Zambia where a local source was identified. For the remaining 308 PUFs, PFOA had a higher median value (188 pg/PUF) than SPFOS (125 pg/PUF) whereas the mean value of SPFOS (254 pg/PUF) was slightly higher than the mean value for PFOA (230 pg/PUF). PFHxS concentrations were much lower in concentration and detection frequency and FOSA, as the only relevant PFOS precursor compound, showed a median value of zero. No clear regional differentiation was found.

Regional occurrence of perfluoroalkane substances in human milk for the global monitoring plan under the Stockholm Convention on Persistent Organic Pollutants during 2016-2019.

The human milk monitoring component of the global monitoring plan under the Stockholm Convention on Persistent Organic Pollutants was implemented from 2016 to 2019 and had 44 human milk samples from primiparae collected in 42 countries and analyzed for perfluoroalkane substances (PFAS), at the MTM Research Centre at Örebro University, Sweden. The targeted compounds were restricted to the two listed PFAS (perfluorooctane sulfonic acid, PFOS and perfluorooctane carboxylic acid, PFOA) and the one recommended PFAS (perfluorohexane sulfonic acid, PFHxS). PFOA was quantified in all 44 samples in a quite narrow range (6.20 pg/g-37.4 pg/g); PFHxS was quantifiable in only four samples (max. 111 pg/g), and PFOS in 36 samples across a wide range (<6.2 pg/g-212 pg/g). Branched PFOS isomers on average had a share of 16% of the total PFOS with a maximum of 33%. PFOS was highly correlated with PFHxS (Pearson correlation coefficient R = 0.95) and weakly but still positively with PFOA (R = 0.44). Statistical analysis (all on p<0.05) showed that PFOS and PFOA in European countries were significantly different from those in African and Latin American countries and between high-income and low-income countries. PFOA tends to have higher concentrations in wealthier countries. No correlation was found for population density.

Priority perfluoroalkyl substances in surface waters - A snapshot survey from 22 developing countries.

The Stockholm Convention on Persistent Organic Pollutants (POPs) has established a global monitoring plan (GMP) to generate comparable data on the presence of POPs listed in the Stockholm Convention to identify changes in POPs concentrations over time and in regions. Perfluoroalkyl substances (PFAS) have been listed into the annexes of the Stockholm Convention in 2009 and 2019, namely perfluorooctane sulfonic acid (PFOS), its salts and perfluorooctane sulfonyl fluoride and perfluorooctanoic acid (PFOA), its salts and PFOA-related compounds. Perfluorohexane sulfonic acid (PFHxS) is recommended for listing in 2021. Surface water samples from 22 countries through the UNEP/Global Monitoring Plan 2 projects were collected from 2017 until 2019. 144 water samples from Africa (n=44), Asia-Pacific (n=60), and the Group of Latin America and Caribbean countries (GRULAC) (n=40) were analyzed using a ultra-performance liquid chromatograph coupled to a tandem mass spectrometer (UPLC-MS/MS). The three PFAS were quantified in the range of 0.03 ng L-1 to 6.23 ng L-1 for ΣPFOS, 0.05 ng L-1 to 4.02 ng L-1 for PFOA and 0.03 ng L-1 to 3.51 ng L-1 for PFHxS. Variation between or within regions, time points, countries' economy and population density was assessed. Statistically significant difference was found only for the PFOA concentration in the Asia Pacific region (11 countries) in comparison to Africa (seven countries) and GRULAC (five countries). Using the standardized sampling protocol for surface waters, these data may serve as a baseline for future monitoring activities and the starting point for trend assessment.

4-Hexylphenol influences adipogenic differentiation and hepatic lipid accumulation in vitro.

Finding the potential environmental obesogens is crucial to explain the prevalence of obesity and the related pathologies. Increasing evidence has showed that many chemicals with endocrine disrupting effects can disturb lipid metabolism. Whether 4-hexylphenol (4-HP), a widely-used surfactant and a potential endocrine disrupting chemical (EDC), is associated to influence adipogenesis and hepatic lipid accumulation remained to be elucidated. In this study, both the 3T3-L1 differentiation model and oleic acid (OA)-treated HepG2 cells were used to investigate the effects of 4-HP on lipid metabolism, and the underlying estrogen receptor (ER)-involved mechanism was explored using MVLN assay, molecular docking simulation and the antagonist test. The results based on lipid droplet staining and triglyceride accumulation assay showed that 4-HP treatment promoted the adipogenic differentiation of 3T3-L1 cells and increased hepatic cellular OA accumulation in exposure concentration-dependent manners. The study on the elaborated transcription networks indicated that 4-HP activated peroxisome proliferator-activated receptor γ (PPARγ) as well as the subsequent adipogenic gene program in 3T3-L1 cells. This chemical also induced the increase of OA uptake and decreases of de novo lipogenesis and fatty acid oxidation in HepG2 cells. The agonistic activity of 4-HP in triggering ER-mediated pathway was shown to correlate with its perturbation in lipid metabolism, as evidenced by the enhanced development of mature lipid-laden adipocytes and suppression of excessive hepatic lipid accumulation upon its co-treatment with ER antagonist. Altogether, these findings provide new insights into the potential health impacts of 4-HP exposure as it may relate to obesity and nonalcoholic fatty liver disease.

A Critical Review of a Recommended Analytical and Classification Approach for Organic Fluorinated Compounds with an Emphasis on Per- and Polyfluoroalkyl Substances.

Organic fluorinated compounds have been detected in various environmental media and biota. Some of these compounds are regulated locally (e.g., perfluorononanoic acid maximum contaminant level in drinking water by the New Jersey Dept. of Environmental Protection), nationally (e.g., perfluorooctanoic acid maximum acceptable concentration in drinking water by Health Canada), or internationally (e.g., Stockholm Convention on Persistent Organic Pollutants). Globally, regulators and researchers seek to identify the organic fluorinated compounds associated with potential adverse effects, bioaccumulation, mobility, and persistence to manage their risks, and, to understand the beneficial attributes they bring to products such as first responder gear, etc. Clarity is needed to determine the best analytical method for the goal of the analyses (e.g., pure research or analysis to determine the extent of an accidental release, monitoring groundwater for specific compounds to determine regulatory compliance, and establish baseline levels in a river of organic fluorinated substances associated with human health risk prior to a clean-up effort). Analytical techniques that identify organic fluorine coupled together with targeted chemical analysis will yield information sufficient to identify public health or environmental hazards. Integr Environ Assess Manag 2021;17:331-351. © 2020. W.L. Gore & Associates Inc. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).

Trace level analyses of selected perfluoroalkyl acids in food: Method development and data generation.

To comprise the future requirements to detect low levels of perfluoroalkyl acids (PFAAs) including branched and linear perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and perfluorohexane sulfonic acid (PFHxS) in food items, analytical methods for their determination in five different food matrices (cow milk, butter, chicken meat, beef, and fish) were developed and validated. Analytical method for eggs was only validated for PFOS and PFOA because of interfering substance appeared in some samples. The method applied on foods of animal origin includes alkaline digestion, extraction, and clean-up with solid phase extraction and adsorption on granular carbon where necessary. The method was shown effective to eliminate taurodeoxycholic acid (TDC), a bile acid that is an endogenous interference compound in egg samples causing ionization suppression and false positive result for PFOS when 499 > 80 transition was used for quantification. The validation was performed and resulted in recoveries >70% for all three PFAAs, the limits of quantification (LOQs) in all matrices were 3.1 pg g-1, 3.4 pg g-1, and 4.9 pg g-1 for PFHxS, PFOA, and L-PFOS, respectively. The optimized method was successfully applied to 53 food samples from the Swedish market and from developing countries. PFOS and PFOA were detected in all samples. PFHxS was detected in 76% of the samples. Further method development on separating interfering substance from PFHxS in egg is warranted due to relatively high detection of this compound in other food items. With this method, concentrations in the low pg g-1 range in food samples of animal origin were quantified including the branched PFOS isomers. This method can be applied to enforce potential future limit values for PFOS and PFOA as a consequence of the recent European Food Safety Authority (EFSA) recommendation where the tolerable intakes have been drastically lowered. Further method development is needed for foods of plant origin such as vegetables, flour, nuts, or bread.