Dynamics of leaching of POPs and additives from plastic in a Procellariiform gastric model: Diet- and polymer-dependent effects and implications for long-term exposure.

Procellariiform seabirds are known to have high rates of plastic ingestion. We investigated the bioaccessibility of plastic-associated chemicals [plastic additives and sorbed persistent organic pollutants (POPs)] leached from plastic over time using an in vitro Procellariiform gastric model. High-density polyethylene (HDPE) and polyvinyl chloride (PVC), commonly ingested by Procellariiform seabirds, were manufactured with one additive [decabrominated diphenyl ether (PBDE-209) or bisphenol S (BPS)]. HDPE and PVC added with PBDE-209 were additionally incubated in salt water with 2,4,4'-trichloro-1,1'-biphenyl (PCB-28) and 2,2',3,4,4',5'-hexachlorobiphenyl (PCB-138) to simulate sorption of POPs on plastic in the marine environment. Our results indicate that the type of plastic (nature of polymer and additive), presence of food (i.e., lipids and proteins) and gastric secretions (i.e., pepsin) influence the leaching of chemicals in a seabird. In addition, 100% of the sorbed POPs were leached from the plastic within 100 hours, while only 2-5% of the additives were leached from the matrix within 100 hours, suggesting that the remaining 95% of the additives could continue to be leached. Overall, our study illustrates how plastic type, diet and plastic retention time can influence a Procellariform's exposure risk to plastic-associated chemicals.

Sliding Windows in Ion Mobility (SWIM): A New Approach to Increase the Resolving Power in Trapped Ion Mobility-Mass Spectrometry Hyphenated with Chromatography.

Over the past decade, the separation efficiency achieved by linear IMS instruments has increased substantially, with state-of-the-art IM technologies, such as the trapped ion mobility (TIMS), the cyclic traveling wave ion mobility (cTWIMS), and the structure for lossless ion manipulation (SLIM) platforms commonly demonstrating resolving powers in excess of 200. However, for complex sample analysis that require front end separation, the achievement of such high resolving power in TIMS is significantly hampered, since the ion mobility range must be broad enough to analyze all the classes of compounds of interest, whereas the IM analysis time must be short enough to cope with the time scale of the preseparation technique employed. In this paper, we introduce the concept of sliding windows in ion mobility (SWIM) for chromatography hyphenated TIMS applications that bypasses the need to use a wide and fixed IM range by using instead narrow and mobile ion mobility windows that adapt to the analytes' ion mobility during chromatographic separation. GC-TIMS-MS analysis of a mixture of 174 standards from several halogenated persistent organic pollutant (POP) classes, including chlorinated and brominated dioxins, biphenyls, and PBDEs, demonstrated that the average IM resolving power could be increased up to 40% when the SWIM mode was used, thereby greatly increasing the method selectivity for the analysis of complex samples.

Validation of an HPLC-MS/MS method with QuEChERS extraction using isotopic dilution to analyze chlordecone in human serum.

Until 1993, chlordecone (CLD) was extensively used in banana fields in French West Indies. In a previous study, CLD was detected in 90 % of Martinican and Guadeloupean adult's serum. In order to simplify the analyses of CLD in the serum, a new QuEChERS-HPLC-MS/MS method was implemented and validated by the Pasteur Institute of Guadeloupe (IPG). This method was validated with accuracy profiles according to the French Standard NF V03-110 plus the ISO 15189 and European guidelines. Linearity, repeatability, accuracy, intermediate precision, specificity, limit of detection (LOD), limit of quantification (LOQ) and uncertainty were determined. The accuracy profile allowed the method to be validated between 0.06  µg L-1 and 1.00  µg L-1 of serum. The LOD was 0.02  µg L-1, the LOQ was 0.06  µg L-1 and the uncertainty of the method was 21 %. A comparison of 49 serum samples between the IPG (LC-MS/MS) and the LEAE-CART (GC-HRMS) laboratories demonstrated that this new method can reliably determine CLD in human serum. Stability tests were performed and duration of the storage of raw samples and extracts before analysis by HPLC-MS/MS. Raw samples were stable after collection for at least one week at 5 °C or 25 °C and for at least 3 months at -20 °C. Extracts in acetonitrile were stable for at least 1 month at -20 °C. These stability results facilitate the daily use of the method. This method should help the entire population of Guadeloupe and Martinique by allowing a routinely analyzed for CLD and will be useful for future projects aimed at improving population health monitoring.

Characterizing the formation of process contaminants during coffee roasting by multivariate statistical analysis.

Coffee is a relevant source of dietary exposure for neoformed furan, alkyl furans and acrylamide. In this study, different statistical methods (hierarchical cluster analysis, correlation analysis, partial least squares regression analysis) were used for characterizing the formation of these process contaminants in green coffee beans roasted under the same standardized conditions. The results displayed a strong correlation between sucrose levels and furans in relation to the other sugars analyzed, while acrylamide formation was strongly related to the free asparagine. The data suggest that a sufficiently large amino acid pool in green coffee favors Maillard-induced acrylamide formation from asparagine, while reactions amongst the carbonyl-containing sugar fragmentation products leading to furan formation are suppressed. If the pool of free amino acids is small, it is depleted faster during roasting, thus favoring the formation of furans by caramelization, basically a sugar degradation process in which reactive carbonyl substances are generated and react together.

Hazard Ratio and Hazard Index as Preliminary Estimators Associated to the Presence of Furans and Alkylfurans in Belgian Foodstuffs.

This paper provides an estimation of the hazard related to the presence of furan and five alkyl furans (2- and 3-methylfuran, 2-ethylfuran, 2,5- and 2,3-dimethylfuran) in foodstuffs available in the Belgian market. To achieve this objective, a specific sampling plan was designed to ensure that the samples collected (n = 1003) represent the diversity of the Belgian food chain. Herein, the concepts of the Hazard Ratio of a sample (HRs) and the Hazard Index of a sample (HIs) were introduced to primarily characterize the hazard related to the co-occurrence of these compounds. The HRs was measured as the ratio of the potential daily exposure to a substance (expressed in mg/Kg of food) to both the 10% reference dose level for chronic effects (expressed in mg/(kg b.w*day)) and the human standard weight (expressed in kg). Whereas the HIs is the sum of the HRs of compounds that affect the same target organ/system, a hazard index greater than one indicates a highly contaminated matrix that could induce a hazard. It is an alarm indicating that additional attention should be given to this matrix. This may involve additional analyses to confirm the high level, to identify sources, etc. It is also an alarm for the risk assessor to be very careful with flagged matrices and to avoid combination with other matrices. The HIs highlight a relatively low concern for all foods analyzed (HI median < 1.0) with a relatively higher suspected hazard for coffee drinks (HI median = 0.068, HI max = 0.57). This preliminary estimation of the potential hazard suggests that coffee beverages should be examined in more detail in a full risk assessment and that coffee consumption should be taken with caution given the levels of furan and alkylfurans reported in this study.

Consumption Habits and Brand Loyalty of Belgian Coffee Consumers.

Coffee is usually subjected to a roasting process which is responsible for the formation of aroma and flavours but also of some undesirable compounds such as furan and alkyl furans. These compounds are known as process contaminants of the roasting process and exhibit some harmful effects. In order to evaluate the exposure to these compounds in coffee, it is necessary to know the levels of contamination as well as consumption habits. The degree of consumers' loyalty to specific coffee brands could also be an important driver affecting the level of exposure. This research aimed to evaluate the levels of consumption and the degree of loyalty to coffee brands available in Belgian markets, as well as the factors affecting the choice and the consumption of coffee products and coffee brands. Data were collected in Belgium through an online survey. The results show that for the 1930 participants, 87% reported daily coffee consumption and 13% never or occasionally consumed coffee. The global median coffee consumption was 3 cups per day, and the median for individual daily consumers only was 4 cups per day. The level of consumption of ground coffee was about twice higher than coffee beans, followed by instant coffee and relatively very low consumption of coffee substitutes. In total, 78% of participants reported brand loyalty but to different degrees. Two coffee brands sold in Belgian regions were listed together by more than 20% of the survey participants. The most frequent criteria for selecting a specific coffee brand were taste and price, followed by tradition and habit. The age of coffee consumers and several sociodemographic characteristics have significant effects on coffee consumption. The type of coffee product, the degree of loyalty, and also the type of packaging should be further considered (when available) in the exposure assessment to furan compounds.

Predicting consequences of POP-induced disruption of blubber glucose uptake, mass gain rate and thyroid hormone levels for weaning mass in grey seal pups.

Persistent organic pollutants (POPs) are endocrine disruptors that alter adipose tissue development, regulation and function. Top marine predators are particularly vulnerable because they possess large fat stores that accumulate POPs. However, links between endocrine or adipose tissue function disruption and whole animal energetics have rarely been investigated. We predicted the impact of alterations to blubber metabolic characteristics and circulating thyroid hormone (TH) levels associated with polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and organochlorine pesticides (OCPs) on suckling mass gain and weaning mass in wild grey seal pups. Glucose uptake by inner blubber was a strong predictor of whole animal mass gain rate, which in turn, resulted in heavier weaning mass. Weaning mass was predicted to increase by 3.7 ± 1.59 (sem) %, through increased mass gain rate, in the absence of the previously reported suppressive effect of dioxin-like PCB (DL-PCBs) on blubber glucose uptake. PBDEs were, conversely, associated with faster mass gain. Alleviation of this effect was predicted to reduce weaning mass by 6.02 ± 1.86% (sem). To better predict POPs effects on energy balance, it is crucial to determine if and how PBDEs promote mass gain in grey seal pups. Weaning mass was negatively related to total T3 (TT3) levels. A 20% (range = 9.3-31.7%) reduction in TT3 by DL-PCBs partially overcame the effect of DL-PCB -mediated reduction in blubber glucose uptake. Overall, DL-PCBs were thus predicted to reduce weaning mass by 1.86 ± 1.60%. Organohalogen impacts on whole-animal energy balance in grey seal pups appear to partially offset each other through opposing effects on different mechanisms. POP effects were generally minor, but the largest POP-induced reductions in weaning mass were predicted to occur in pups that were already small. Since weaning mass is positively related to first-year survival, POPs may disproportionately affect smaller individuals, and could continue to have population-level impacts even when levels are relatively low compared to historical values. Our findings show how in vitro experiments combined with measurements in vivo can help elucidate mechanisms that underpin energy balance regulation and help to quantify the magnitude of disruptive effects by contaminants and other stressors in wildlife.

Optimization and Validation of HS-SPME-GC-MS for the Determination of Furan and Alkylfurans in Chocolate-Based Products: Impact of Tempering and Laser Printing.

BACKGROUND: Furan and its alkyl substituted (2-methylfuran, 3-methylfuran, 2,3-dimethylfuran, 2,5-dimethylfuran) are found in a range between ppm to sub-ppb levels in many foodstuffs undergoing heat treatments like coffee, chicory, or even chocolate. OBJECTIVES: Two major objectives are presented. First, we aim at optimizing and validating a HS-SPME-GC-MS method for the quantification of five alkylfurans in chocolate. Second, we focus our study on measuring the quantitative impact of engraving technique on the formation of furan and its derivatives in chocolate, from the raw callets to processed end-products. METHOD: HS-SPME-GC-MS method operating in SIM mode and using isotope dilution technique with deuterated homologue internal standards was used to quantify alkylfurans in chocolate. RESULTS: Good repeatability (RSD% = 0.1-8%, in duplicate) and intermediate precision (RSD% = 1.7-7%, n = 6) were obtained for these five process contaminants at 10, 25, and 50 µg/kg. Trueness was varying between 81 and 109%. LoQ ranged from 0.48 to 2.50 µg/kg. Relative expanded measurement uncertainties ranged from 6 to 30%. Finally, tempering is responsible for a 24% increase in furan contamination, while the laser engraving technique results in an additional 31% increase in furan. A similar trend was also observed for 2-methylfuran and 3-methylfuran, whereas no significant increases were observed for 2,3-dimethylfuran and 2,5-dimethylfuran. CONCLUSIONS AND HIGHLIGHTS: A reliable and sensitive method of HS-SPME-GC-MS was reported for the first time for the analysis of furan and four alkylfurans in chocolate. This paper demonstrated that engraving using laser-based techniques can increase the levels of these compounds by up to 30%.

High pollutant exposure level of the largest European community of bottlenose dolphins in the English Channel.

The objective of this study was to assess the levels of persistent organic pollutants (POPs) and mercury (T-Hg) in the blubber and skin, respectively, of the free-ranging bottlenose dolphins, Tursiops truncatus, from the Normanno-Breton Gulf, one of the largest identified coastal population in Europe. Among all the POPs analysed in this study, the ∑NDL-PCBs were the most abundant compounds found in the blubber (mean: 1.33 × 105-0.65 × 105 ng.g-1 lipid weight (lw) for males and females respectively), followed by ∑DDX (1.11 × 104-4.67 × 103 ng.g-1 lw) > ∑DL-PCBs (8.06 × 103-2.62 × 103ng.g-1 lw) > ∑PBDEs (1.95 × 103-0.64 × 103ng.g-1 lw) > dieldrin (1.86 × 103-0.18 × 103 ng.g-1 lw) > ∑endosulfan (405-62 ng.g-1 lw) > HCB (86-52 ng.g-1 lw) > ∑HCHs (47-60 ng.g-1 lw) > ∑chlordane (24-0.97 ng.g-1 lw) > ∑PCDFs (0.3-0.1 ng.g-1 lw) > ∑PCDDs (0.06-0.05 ng.g-1 lw). The T-Hg concentrations were highly variable between individuals (2.45 × 103 ng.g-1 to 21.3 × 103 ng.g-1 dry weight, dw). The reported concentrations are among the highest reported for cetaceans. We strongly recommend that the Normanno-Breton Gulf be a special area of conservation (cSAC) candidate because it contains the last large European population of bottlenose dolphins (rare or threatened within a European context) designated under the EC Habitats Directive.

The performance of atmospheric pressure gas chromatography-tandem mass spectrometry compared to gas chromatography-high resolution mass spectrometry for the analysis of polychlorinated dioxins and polychlorinated biphenyls in food and feed samples.

Recently, gas chromatography tandem mass spectrometry (GC-MS/MS) has been added in European Union (EU) legislation as an alternative to magnetic sector high resolution mass spectrometry (HRMS) for the analysis of dioxins and dioxin like polychlorinated biphenyls (dl-PCB) in food and feed. In this study the performance of APGC-MS/MS compared to GC-HRMS is investigated and compared with EU legislation. The study includes the legislative parameters, relative intermediate precision standard deviation (SRw,rel), trueness, sensitivity, linear range and ion ratio tolerance. In addition, over 200 real samples of large variety and spanning several orders of magnitude in concentration were analyzed by both techniques and the selectivity was evaluated by comparing chromatograms. The SRw,rel and trueness were evaluated using (in-house) reference samples and fulfill to EU legislation, though the SRw,rel was better with GC-HRMS. The sensitivity was considerably better than of GC-HRMS while the linear range was similar. Ion ratios were mostly within the tolerable range of ±15%. A (temporary unresolved) systematic deviation in ion ratio was observed for several congeners, yet this did not lead to exceeding of the maximum ion ratio limits. The APGC-MS/MS results for the non-dioxin-like-PCBs (ndl-PCBs) were negatively biased, particularly for PCB138 and 153 in contaminated samples. The selectivity of APGC-MS/MS was lower for several matrices. Particularly for contaminated samples, interfering peaks were observed in the APGC chromatograms of the native compounds (dioxins) and labeled internal standards (PCBs). These can lead to biased results and ultimately to false positive samples. It was concluded that the determination of dioxins and PCBs using APGC-MS/MS meets the requirements set by the European Commission. However, due to generally better selectivity and SRw,rel, GC-HRMS is the preferred method for monitoring purposes.

Dietary early-life exposure to contaminated eels does not impair spatial cognitive performances in adult offspring mice as assessed in the Y-maze and the Morris water maze.

Many environmental contaminants are introduced via the diet and may act as neurotoxins and endocrine disrupters, especially influencing growing organisms in early life. The purpose of this study was to examine whether dietary exposure of dams to fish naturally contaminated with xenobiotics, especially with polychlorinated biphenyls (PCBs) and heavy metals (e.g., mercury and lead), resulted in cognitive function deficits in adult offspring mice. Daily, four groups of dams (n = 10/group) ingested standard diet plus paste with/without eels, during gestation and lactation, from gestational day (GD) six until post natal day (PND) 21 (weaning). Dams orally ingested a standardized amount of eel (0.8 mg kg(-1) d(-1)) containing the six non-dioxin-like (NDL) PCBs (Σ6 NDL-PCBs: 28, 52, 101, 138, 153, and 180) at 0, 85, 216, and 400 ng kg(-1) d(-1). Results showed that early-life exposure to contaminated eels did not (compared to non-exposed controls) impair immediate working memory in the Y-maze in the offspring assessed at PND 38. Furthermore, it did not significantly impact spatial learning and retention memory as measured in the Morris water maze in adult offspring mice (PND 120-123). Our results suggest that perinatal exposure to contaminated eels does not affect spatial cognitive performances, as assessed by the Y-maze and Morris water maze at adult age. Adverse effects of xenobiotics reported earlier might be camouflaged by beneficial eel constituents, such as n-3 fatty acids. However, additional studies are needed to differentiate between potential positive and negative effects following consumption of food items both rich in nutrients and contaminants.

Levels of dechloranes and polybrominated diphenyl ethers (PBDEs) in human serum from France.

Human exposure to dechloranes has been evaluated in Western Europe (France) with the analysis of Dechlorane Plus (DP), Dechloranes (Dec) 602, 603 and 604, Chlordene Plus (CP) and Mirex in 48 serum samples collected between 2003 and 2005. While no production source has been identified in Europe until now, detection frequencies for all investigated dechloranes were high, except for Dec 604 which was below detection limit for all samples. The mean DP concentration was 1.40±1.40ng/g lipid weight (lw), lower than levels reported in serum from Chinese population, but higher than levels reported in Canadian human milk. To the best of our knowledge, this is the first time that ∑5dechlorane levels are reported for human serum. A specific pattern of contamination was found (Dec 603>DP>Mirex>Dec 602>CP) compared to other biota samples that have been analyzed from Europe, with Dec 603 as the most abundant dechlorane (mean level: 2.61±2.63ng/g lw). Dec 603 and CP levels were correlated with age and with levels of some bioaccumulative organochlorine pesticides (OCPs). These results indicate that bioaccumulation properties should be further investigated and taken in consideration when assessing human exposure to dechloranes. For comparison purposes, polybrominated diphenyl ether (PBDE) levels were also measured for BDE-47, -99, -100, -153 and -154 in the serum samples. As expected, BDE-47 and BDE-153 were the major congeners with mean levels of 2.06±1.80ng/g lw and 1.39±0.97ng/g lw, respectively. The mean ∑5PBDE levels (4.32±2.99ng/g lw) were in the range typical of Western Europe levels, but lower than the mean ∑5dechlorane levels (6.24±4.16ng/g lw). These results indicate that the attention to dechloranes should be continued if research indicates toxicological concerns.

Preliminary assessment of the risk linked to furan ingestion by babies consuming only ready-to-eat food.

The risk linked to furan ingestion has been assessed in previous papers for Belgian adults and children. The present paper focuses on infants consuming only ready-to-eat baby food. As there is no Belgian baby dietary database, the furan exposure assessment was carried out by using an Italian infant consumption database and Belgian contamination data. The estimated daily intake (EDI) was calculated according to a deterministic methodology. It involved 42 commercially available ready-to-eat baby food and 36 baby consumption records. The mean EDI was 1460 ng*(kg(bw)*day)⁻¹ which is 3.8 times higher than the 381 ng*(kg(bw)*day)⁻¹ reported for Belgian adults, and 3.5 times higher than the 419 ng*(kg(bw)*day)⁻¹ measured for Belgian children. To assess and characterise the risk for babies' exposure, the margin of exposure (MoE) was calculated. It highlighted that 74% of infants have a MoE < 1000, with a minimum of 140. However, these are only preliminary results as they were calculated from a very small dataset and the infant cytochrome P450 activity is significantly different compared with the adult's. Therefore, the risk linked to furan ingestion by babies should be assessed in a different manner. To this end, additional data regarding a baby diet as well as a better understanding of furan toxicity for babies are needed to characterise more accurately the risk for infants.

Levels of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in human milk from different regions of France.

We report on the pilot study carried out before the start of the Elfe project (French longitudinal study from childhood). A total of 44 samples of mature human milk were collected at home 8 weeks after delivery. A total of 7 polychlorinated dibenzo-p-dioxins (PCDDs), 10 polychlorinated dibenzofurans (PCDFs), 12 dioxin-like (DL) polychlorinated biphenyls (PCBs), and 6 non dioxin-like (NDL)-PCBs were measured. For total TEQ (PCDD/Fs and DL-PCBs), the geometric mean concentration was 17.81 pg TEQ(WHO05)/g lipids. Relative PCDD, PCDF, and DL-PCB contributions to the arithmetic mean TEQ(WHO05) were 38%, 18%, and 44%, respectively. The use of TEF(WHO05) instead of TEF(WHO98) resulted in a 27% reduction of the total TEQ value. Although PCDD levels did not significantly change (less than 0.5% increase), PCDF and DL-PCB levels both decreased by 35% and 38%, respectively. Levels have been compared to data obtained during a previous non-reported national study conducted in 1998 (TEF(WHO98)) in French lactaria (n=244). The mean of PCDD/Fs has decreased about 39.4% (18.8 pg TEQ(WHO98)/g lipids in 1998 vs 11.4 pg TEQ(WHO98)/g lipids in pilot study), respectively 41.5% for PCDDs (10.6 pg TEQ(WHO98)/g lipids in 1998 vs 6.2 pg TEQ(WHO98)/g lipids in pilot study) and 36.7% for PCDFs (7.9 pg TEQ(WHO98)/g lipids in 1998 vs 5.0 pg TEQ(WHO98)/g lipids in pilot study). For the sum of the 6 NDL-PCBs, the 2007 geometric mean concentration in milk was 176.3 ng/g lipids. The arithmetic mean lipid concentration in 2007 breast milk was 26.4 g/l (range from 6.0 to 46.7 g/l). A PCDD/F and DL-PCB daily intake was estimated to be 62.3 pg TEQ(WHO05)/kg body weight per day (85.0 pg TEQ(WHO98)/kg body weight per day) for a baby of 5 kg of body weight fed daily with 700 ml of maternal milk containing 25 g/l of lipids.

Risk assessment for furan contamination through the food chain in Belgian children.

Young, old, pregnant and immuno-compromised persons are of great concern for risk assessors as they represent the sub-populations most at risk. The present paper focuses on risk assessment linked to furan exposure in children. Only the Belgian population was considered because individual contamination and consumption data that are required for accurate risk assessment were available for Belgian children only. Two risk assessment approaches, the so-called deterministic and probabilistic, were applied and the results were compared for the estimation of daily intake. A significant difference between the average Estimated Daily Intake (EDI) was underlined between the deterministic (419 ng kg⁻¹ body weight (bw) day⁻¹) and the probabilistic (583 ng kg⁻¹ bw day⁻¹) approaches, which results from the mathematical treatment of the null consumption and contamination data. The risk was characterised by two ways: (1) the classical approach by comparison of the EDI to a reference dose (RfD(chronic-oral)) and (2) the most recent approach, namely the Margin of Exposure (MoE) approach. Both reached similar conclusions: the risk level is not of a major concern, but is neither negligible. In the first approach, only 2.7 or 6.6% (respectively in the deterministic and in the probabilistic way) of the studied population presented an EDI above the RfD(chronic-oral). In the second approach, the percentage of children displaying a MoE above 10,000 and below 100 is 3-0% and 20-0.01% in the deterministic and probabilistic modes, respectively. In addition, children were compared to adults and significant differences between the contamination patterns were highlighted. While major contamination was linked to coffee consumption in adults (55%), no item predominantly contributed to the contamination in children. The most important were soups (19%), dairy products (17%), pasta and rice (11%), fruit and potatoes (9% each).

Furan formation from lipids in starch-based model systems, as influenced by interactions with antioxidants and proteins.

The formation of furan upon sterilization of a lipid-containing starch gel was investigated in the presence of various antioxidants, namely, α-tocopherol, ß-carotene, and ascorbic acid, with and without proteins. Results indicated that α-tocopherol did not significantly influence furan formation from oxidized lipids. ß-Carotene, suggested previously to be a furan precursor itself, did influence the generation of furan in a concentration-dependent manner, although to a limited extent. Surprisingly, the presence of lipids seemed to limit the furan generation from ß-carotene. Interestingly, the addition of ascorbic acid to the emulsions containing soybean or sunflower oils considerably enhanced the formation of furan from these oils. This was also the case when fresh oils were applied, shown previously to be nearly unable to generate furan. This observation can be explained by an intensified ascorbic acid degradation stimulated by the presence of lipids.

Importance of fat oxidation in starch-based emulsions in the generation of the process contaminant furan.

The formation of the possibly carcinogenic process contaminant furan was studied in starch-based emulsions during heat treatments as applied for sterilization. Fresh and oxidized soybean, sunflower, high-oleic sunflower, olive, linseed, and rapeseed oils were compared. Results indicated that both the oil type, in particular, the fatty acid composition, and the oxidation degree of the oil determined the susceptibility of the oils to generate furan upon heating. Thus, oils containing the nutritionally relevant omega-3 unsaturated alpha-linolenic acid proved to be able to generate significant amounts of furan if the oils were oxidized. No clear relationship between p-anisidine values of various oils and the amount of generated furan could be observed. However, in the case of soybean oil, significantly more furan was produced upon an increase in oxidation degree. Surprisingly, furan formation in food-relevant systems containing fresh lipids proved to be a minor route (up to 1.5 ppb furan) compared to a previously studied vitamin C containing model system (up to 13 ppb furan).

High-throughput biomonitoring of dioxins and polychlorinated biphenyls at the sub-picogram level in human serum.

We report on the use of a state-of-the-art method for the measurement of selected polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in human serum specimens. The sample preparation procedure is based on manual small size solid-phase extraction (SPE) followed by automated clean-up and fractionation using multi-sorbent liquid chromatography columns. SPE cartridges and all clean-up columns are disposable. Samples are processed in batches of 20 units, including one blank control (BC) sample and one quality control (QC) sample. The analytical measurement is performed using gas chromatography coupled to isotope dilution high-resolution mass spectrometry. The sample throughput corresponds to one series of 20 samples per day, from sample reception to data quality cross-check and reporting, once the procedure has been started and series of samples keep being produced. Four analysts are required to ensure proper performances of the procedure. The entire procedure has been validated under International Organization for Standardization (ISO) 17025 criteria and further tested over more than 1500 unknown samples during various epidemiological studies. The method is further discussed in terms of reproducibility, efficiency and long-term stability regarding the 35 target analytes. Data related to quality control and limit of quantification (LOQ) calculations are also presented and discussed.