Fluorinated Liquid-Crystal Monomers in Serum from the General Population and Their Impact on Human Health.

Fluorinated liquid-crystal monomers (FLCMs) are a potential emerging class of persistent, bioaccumulative, and toxic compounds. Humans inevitably ingest FLCMs via food and the environment. However, there are limited studies on internal exposure biomonitoring of FLCMs. Herein, we evaluated the estimated daily intakes (EDIs) of FLCMs in the general population based on serum residue levels. For the first time, 38 FLCMs were detected in 314 serum samples from the general population in Beijing, with a median value of 132.48 ng/g of lipid weight (lw). BDPrB is a predominant FLCM in serum. The median EDI of ∑38FLCMs in the general residents was 37.96 pg/kg bw/day. The residual levels of most FLCMs were higher in urban than in suburban areas (p < 0.05). The concentrations of EFPEB, EDPrB, EDFPBB, and PDTFMTFT in serum showed positive associations with blood glucose (GLU) (r = 0.126-0.275, p < 0.05). Logistic regression analysis showed that FLCMs were significantly positively correlated with dyslipidemia, with an odds ratio of 2.19; BDPrB was significantly positively correlated with hyperglycemia (OR: 2.48). Overall, the present study suggests the occurrence of FLCMs in the nonoccupational population, and the exposure of certain FLCMs may cause abnormal blood glucose and lipid levels.

Characterizing the cumulative health risks of 19 kinds of pesticides in Chinese food from the cancer and non-cancer perspective.

Food safety is an important issue of most concern for health, while pesticides are one of the main threats to food safety. In view of the potential health hazard of pesticides in food, the cancer and non-cancer risks were assessed for 19 kinds of pesticides in Chinese food in this study. Furthermore, the health risks of different types of pesticides were compared to uncover the most polluted pesticide types in this study. Results show that methyl parathion, dichlorvos and 2,4-D residues in some food groups exceed the Chinese food standards. The cumulative disease burden of six carcinogenic pesticides for people older than 40 years ranges from 1.03 × 10-6 to 2.27 × 10-6, which exceeds the WHO recommended limit of 10-6. The non-cancer risks of 13 kinds of pesticides are all lower than 1 and will not pose appreciable health risk to the consumers. Livestock and poultry (contribution rate = 38.93%) and Milk and dairy products (contribution rate = 22.38%) are the dominate risk exposure sources for carcinogenic pesticides while staple foods (contribution rate = 31.62%) and vegetables (contribution rate = 21.5%) are the main risk exposure sources for non-carcinogenic pesticides. Comparing the risks of different pesticide types, insecticide is the most harmful category in this study, followed by herbicide and acaricide. This study characterized the health risks of pesticides in Chinese food and provided a scientific basis for pesticide management.

Dietary Exposure and Health Risk of the Emerging Contaminant Fluorinated Liquid-Crystal Monomers.

Fluorinated liquid-crystal monomers (FLCMs) widely used in liquid crystal displays are considered to be a new generation of persistent, bioaccumulative, and toxic contaminants. They have been widely detected in the environment. However, little is known about their occurrence in food and human dietary exposure until now. Herein, we provided an evaluation of dietary exposure and health risks of FLCMs in the Chinese adult population based on the fifth and sixth total diet studies (TDSs). The detection frequencies of FLCMs in the two surveys were 90.5 and 99.5%, with concentrations ranging from not detected ∼72.6 µg/kg wet weight (ww) and ND ∼74.7 µg/kg ww, respectively. All TDS samples contained the multiresidue of FLCMs. The mean estimated daily intakes (EDIs) of FLCMs were 172.86 and 163.10 ng/kg bw/day in the fifth and sixth TDS, respectively. Meats, vegetables, and cereals contributed the most to the EDI of FLCMs. According to the threshold of toxicological concern (TTC) method, the EDIs of 1-fluoro-4-[2-(4-propylphenyl)ethynyl]benzene (4.56 and 3.26 ng/kg bw/day) and 2-fluoro-4-[4'-propyl-1,1'-bi(cyclohexyl)-4-yl]phenyl trifluoromethyl ether (3.12 and 3.28 ng/kg bw/day) were above their TTC value (2.5 ng/kg bw/day), suggesting their potential health risk. This is the first comprehensive national dietary exposure assessment of FLCMs.

Fast on-Site Visual Detection of Active Ricin Using a Combination of Highly Efficient Dual-Recognition Affinity Magnetic Enrichment and a Specific Gold Nanoparticle Probe.

Ricin, a highly toxic protein, is a controlled substance by both the Chemical Weapons Convention (CWC) and the Biological Weapons Convention (BWC). Therefore, fast precaution of potential ricin toxin plays an important role in national security and public safety. Herein, a simple, sensitive, and accurate visual detection of active ricin in complex samples is presented by combining magnetic affinity enrichment with a specific gold nanoparticle (AuNP) probe. In the first step, a dual-recognition magnetic absorbent was fabricated by simultaneously incorporating two different affinity ligands (concanavalin A and galactosamine) on low-foul polymer brushes grafted magnetic beads, which showed remarkable multivalent synergy binding capacity for ricin even under complex interfering environments. Subsequently, a homoadenine-constituted oligodeoxynucleotide named poly(21dA) was conjugated to AuNPs (the poly(21dA)-AuNPs), which served as a specific depurination substrate of active ricin. Coralyne can trigger the intact poly(21dA)-AuNPs aggregate by forming a non-Watson-Crick homoadenine/coralyne complex, but the poly(21dA)-AuNPs after reacting with active ricin failed to form this complex due to the loss of adenines. Based on these facts, active ricin can be detected as low as 12.5 ng mL-1 with the naked eyes. This detection strategy could be well-applied in various ricin-spiked complex matrices. The features such as ready operation, facile readout, and easy accessibility make the assay a better choice for fast on-site active ricin detection.

Biological effects of new-generation dialkyl phosphinate flame retardants and their hydrolysates in BALB/C mice.

Aluminum methylcyclohexylphosphinate (AMHP), calcium methylcyclohexylphosphinate (CMHP), aluminum diethylphosphinate (ADEP), and aluminum methylethylphosphinate (AMEP) are organic dialkyl phosphinates (DPs) and emerging phosphorus-based flame retardants. The broad-spectrum DPs flame retardants occupy high-end industrial markets, but their ecologic risk has been reported rarely. By exposing male BALB/c mice to DPs and dialkyl phosphinic acids, we studied the toxic effects of these chemicals, and measured AMHP and methylcyclohexylphosphinic acid (MHPA) in blood and feces. We found that DPs and their main hydrolysates had mild toxicity in BALB/c mice. Exposure to 10 and 50 mg/kg/d of AMEP and ADEP caused mild hepatotoxicity in mice. Toxicity of CMHP was in the liver and kidneys. Toxicity of AMHP and its hydrolysate MHPA was low and affected the liver. These data suggest that AMHP has lower toxicity than the other DPs that we tested. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 1578-1586, 2017.

Products of methotrexate during chlorination.

Methotrexate (MTX) is a cytotoxic drug widely used in the treatment of tumors, autoimmune diseases and severe asthma. jen00883This drug has been frequently detected in the aquatic environment with concentrations up to µg/L levels. The MTX present in environmental water might be transformed and removed during chlorination disinfection treatment. In this work, the fate of MTX during aqueous chlorination was investigated in laboratory batch experiments, and the transformation products of MTX were identified. Aqueous solutions of MTX (1mg/L) were chlorinated by sodium hypochlorite solution at room temperature under neutral pH conditions. Chlorinated products were pre-concentrated with solid-phase extraction (SPE) cartridges and determined by liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The reaction of MTX chlorination exhibited pseudo-first-order kinetics and the half-life time of MTX degradation was calculated to be 1.65min, when the initial chlorine concentration was 2mg/L. Two chlorinated MTX congeners, 4-amino-3-chlorinated-N10-methylpteroylglutamic (monochloro-MTX) and 4-amino-3,5-dichloro-N10-methylpteroylglutamic (dichloro-MTX) were found in the chlorinated solution. Monochloro-MTX was successfully fractionated by high performance liquid chromatography (HPLC) and its structure was further identified using 1H nuclear magnetic resonance (NMR) analysis. The presence of the two products in real hospital wastewater was then examined and both compounds were detected. Finally, the effects of MTX and monochloro-MTX on the cell cycle progression in vitro were evaluated using zebrafish liver cell line. It was found that both compounds could inhibit the proliferation of zebrafish liver cells through S phase arrest and their effects on the cell cycle profile had no significant difference.

[Determination of 8 bisphenols in human breast milk by dansyl chloride derivatization-ultra performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a rapid and sensitive method for the analysis of eight bisphenols in breast milk using small amount of samples. METHODS: Breast milk samples were extracted by acetonitrile and the lipid substances were removed by freezing under-20 ℃ condition. Then the samples were derivatized with dansyl chloride and analyzed by ultra-performance liquid chromatography-tandem mass spectrometry( UPLCMS/MS). The seperation was performed on an ACQUITY UPLC BEH Phenyl column( 2. 1 mm × 100 mm, 1. 7 µm) with methanol and 0. 1% formic acid in water as mobile phase. The electrospray source was in the positive ion mode and monitored in the multiple reactions monitoring mode. Isotope internal standard dilution technique was used for the quantification analysis. At last, the methodology was studied. RESULTS: The linear range of 8 bisphenols was 0. 010-10. 00 µg/L. The recoveries of the three spiked levels were84. 6%-108. 1%, with the relative standard deviations no more than 12%( n = 6). 30 samples of breast milk were analyzed, in which BPA was detected in 11 breast milk samples, and the concentrations ranged from 0. 13 µg/L to 2. 25 µg/L. BPAF was detected in 1 breast milk sample, and the concentration was 0. 02 µg/L. CONCLUSION: The established method using a small amount of breast milk is highly sensitive, simple and fast, and can be used for the simultaneous determination of 8 bisphenols in breast milk.

[Total dietary exposure assessment of emerging brominated flame retardants in Beijing].

OBJECTIVE: To estimate the exposure characteristic of six emerging brominated flame retardant for Beijing residents by dietary intake. METHODS: 2,3,5,6-tetrabromo-p-xylene (pTBX), pentabromotoluene (PBT), 1, 2, 3, 4, 5-pentabromo-6- ethylbenzene (PBEB), hexahromobenzene (HBB), hexachlorocyclopentadienyl- dibromocyclooctane (DBHCTD) and 1,2-bis(2 ,4 ,6-tribromo phenoxy) ethane (BTBPE) were detected by atmospheric pressure gas chromatography tandem mass spectrometry (APGC-MS/MS) in total dietary samples from Beijing. Dietary intake assessments of human exposure were carried out according to results of determination. RESULTS: PBT, PBEB, HBB and BTBPE were occurred with concentration between 1.2-29.4 pg/g wet weight. The detection rates of HBB and BTBPE in animal--origin samples were higher than those in plant-origin samples, and there were significant differences (P < 0.05). The exposure level of Beijing residents to six emerging brominated flame retardants were 296.8 pg/(kg-d). CONCLUSION: The exposure level of emerging brominated flame retardants by dietary intake in Beijing is relatively low, and meat is the main source of BTBPE dietary intake.

Evaluating the blank contamination and recovery of sample pretreatment procedures for analyzing organophosphorus flame retardants in waters.

Organophosphate esters (OPEs), used as flame retardants and plasticizers, are widely present in environmental waters. Development of accurate determination methods for trace OPEs in water is urgent for understanding the fate and risk of this class of emerging pollutants. However, the wide use of OPEs in experimental materials results in blank interference, which influences the accuracy of analytical results. In the present work, blank contamination and recovery of pretreatment procedures for analysis of OPEs in water samples were systematically examined for the first time. Blank contaminations were observed in filtration membranes, glass bottles, solid phase extraction cartridges, and nitrogen blowing instruments. These contaminations could be as high as 6.4-64ng/L per treatment. Different kinds of membranes were compared in terms of contamination levels left after common glassware cleaning, and a special wash procedure was proposed to eliminate the contamination from membranes. Meanwhile, adsorption of highly hydrophobic OPEs on the inside wall of glass bottles was found to be 42.4%-86.1%, which was the primary cause of low recoveries and was significantly reduced by an additional washing step with acetonitrile. This work is expected to provide guidelines for the establishment of analysis methods for OPEs in aqueous samples.

Aluminum dialkyl phosphinate flame retardants and their hydrolysates: analytical method and occurrence in soil and sediment samples from a manufacturing site.

Aluminum dialkyl phosphinates (ADPs) are emerging phosphorus flame retardants due to their superior characteristics, but their analytical method, and occurrence and fate in environments have never been reported. For the first time, we developed a method for the analysis of trace ADPs and their hydrolysates (dialkyl phosphinic acids, DPAs), and studied their occurrences and fates in soils and sediments. We found that ADPs are hardly dissolved in water and organic solvents, but are dissolved and hydrolyzed to DPAs in 30 mM NH3·H2O, thus both ADPs and DPAs can be determined by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) in the form of DPAs. ADPs and DPAs in soil and sediment samples were determined by (i) extracting both ADPs and DPAs with 75 mM NH3 · H2O, and selectively extract DPAs only with formic acid-water-methanol (5:5:90, v/v/v); (ii) quantifying the total content of ADPs and DPAs, and DPAs by LC-MS/MS analysis of the DPA contents in the former and the latter extract, respectively; and (iii) calculating ADPs from the content difference between the former and the latter extracts. The limit of quantifications (LOQs) of the proposed method were 0.9-1.0 µg/kg, and the mean recoveries ranged from 69.0% to 112.4% with relative standard deviations ≤ 21% (n = 6). In soil and sediment samples around a manufacturing plant, ADPs and DPAs were detected in surface soils in the ranges of 3.9-1279.3 and 1.0-448.6 µg/kg, respectively. While ADPs were found in all the samples of the soil and sediment cores from the drain outlet and the waste residue treatment site at levels ranging from 30.8 to 4628.0 µg/kg, DPAs were found in more than 90% of these samples with concentrations in the range of 1.1-374.6 µg/kg. The occurrences of ADPs and DPAs are not in correlation with the total organic carbon, whereas the occurrences of DPAs are highly correlated with the sample pH. Our study also suggests that the DPAs in the samples sourced from the hydrolysis of ADPs. The high hydrolysis degrees of ADPs (up to 49.6%) suggest that once released into the environment, ADPs are likely to coexist with their hydrolysates. Thus, to evaluate the environmental safety of ADPs, the environmental behavior and toxicity of both ADPs and DPAs should be considered.

Exploring the formation pathway and antioxidant properties of the sugar-smoking pigment 5-GGMF.

The present study aimed to elucidate the pathway of pigment formation and identify the source of antioxidant activity during sugar smoking. Building upon previous research, this investigation replicated the sucrose cleavage process involved in sugar-smoking through model reactions to obtain distinct model reaction products. The products were analyzed using various techniques such as ultraviolet-visible spectrometry, Fourier-transform infrared spectroscopy, high-performance liquid chromatography, and high-performance liquid chromatography-tandem mass spectrometry. The findings revealed that the pyrolysis of sucrose at 330 °C yielded glucose and fructose, with fructose pyrolysis producing significantly more 5-HMF than glucose. Moreover, the antioxidant capacity of 5-HMF was found to make a substantial contribution. The primary source of 5-HMF was identified as fructose resulting from the cleavage of sucrose at 330 °C, while the primary pathway for the formation of the sugar-smoking pigment 5-GGMF was attributed to the intermolecular dehydration of 5-HMF and glucose at 150 °C.

A SILAC-based accurate quantification of shrimp allergen tropomyosin in complex food matrices using UPLC-MS/MS.

The carryover of trace allergens in complex food matrices poses challenges for detection techniques. Here, we demonstrate an accurate UPLC-MS/MS quantification assay for the shrimp allergen tropomyosin with a full-length isotope-labelled recombinant tropomyosin (TM-I) internal standard in complex food matrices. The TM-I, expressed based on the SILAC technique, exhibited a high isotope labelling ratio (>99%), purity, and alignment with the natural sequence. This method determined the tropomyosin ranging from 0.2 to 100 ng/mL. Mean recoveries ranged from 89 to 116%, with intra- and inter-day RSDs below 12%, for three signature peptides across three types of commercially processed food matrices. The limits of quantitation were 1 µg/g in pop food and sauce, and 10 µg/g in surimi product, respectively. This study supports the use of recombinant full-length isotope-labelled proteins rather than stable-isotope labelling peptides as internal standards to achieve more accurate quantitation of food allergens as the digestion error is corrected.

[An on-line solid phase extraction column switching liquid chromatography tandem mass spectrometry system to analyze bisphenol A and nonylphenol in drinking water].

OBJECTIVE: To develop a method for bisphenol A (BPA) and nonylphenol (NP) analysis in drinking water by on-line solid phase extraction (SPE) column switching liquid chromatography tandem mass spectrometry. METHOD: Target compounds were concentrated and purified by a Waters Direct Connect HP XBridge C18 column, with average particle size 10 microm. The mobile phase of SPE extraction column was methanol/water at a flow-rate of 2.0 ml/min. The analytical column was Waters BEH C18 column (2.1 mm x 50 mm, 1.7 microm) and the mobile phase was methanol/0.1% ammonia water at a flow-rate of 0.4 ml/min. BPA and NP were analyzed by liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) in the negative ion mode with multiple reactions monitoring (MRM). RESULTS: The whole run time of an individual sample was about 10 min. The linear calibration curves covered the range of 5 - 1000 ng/L and 10 - 5000 ng/L for BPA and NP, respectively, while the correlation coefficients (r2) were above 0.999. The quantification limits of the method were 5 and 10 ng/L for BPA and NP, respectively. Recovery test was performed at three fortification levels, mean recoveries ranged from 86.6% to 105% with acceptable coefficients of variation (3.11% - 18.2%, n = 6). The inter-day precisions were less than 13.2%. CONCLUSION: The established On-line SPE LC-MS/MS method needs no complicated sample pretreatment step, which is significantly time-saving. The analytical procedure is rapid, simple, and high-sensitive. It can be applied to analysis BPA and NP in drinking water.

[Determination of 26 bisphenols in dust by ultra performance liquid chromatography-tandem mass spectrometry].

Bisphenol A (BPA) is one of the most widely produced compounds in the world and was listed as a substance of very high concern by the European Chemicals Agency in 2016. Because of its toxicity, many countries and regions, including China, have banned BPA addition in feeding-bottles. And the European Union (EU) has banned BPA use in other food contact materials and thermal paper. Restrictions on BPA have contributed to the widespread use of alternatives. As the toxicity of BPA alternatives continues to be revealed, the alternatives of BPA alternatives are being developing. As the most extensive alternative for BPA, bisphenol S (BPS) was proven to have estrogen-disrupting effects and developmental toxicity of the neuroendocrine system. Therefore, BPS alternatives are used in thermal paper. In this study, alternatives to both BPA and BPS are collectively referred to as bisphenols (BPs). As a pooling matrix of many indoor chemicals, dust is an important pathway for human exposure to BPs. BPA and its alternatives are routinely detected in dust. As BPS alternatives have been detected in recycled paper and sludge, it is also very important to detected in dust. However, common analytical methods for BPs have low sensitivity and contain few BPS alternatives. Therefore, a high-throughput, high-accuracy, and high-sensitivity method must be established for the determination of BPs in dust; this will lay the foundation for subsequent studies on the environmental behavior and exposure risk of BPs. In this study, an ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of 26 variations of BPs in dust. UPLC-MS/MS parameters of the variations were optimized to compare the separation effect and response intensity in different columns and mobile phases. The influence of the extraction solvent and solid phase extraction (SPE) on the extraction efficiency and purification effect of target compounds were optimized by using the isotopic internal standard method, and the 26 variations of BPs in dust was quantitatively analyzed. Finally, the dust samples were extracted by using 3 mL of acetonitrile and 3 mL of a 50% methanol aqueous solution in an ultrasound bath. The combined extract was further purified by using an Oasis HLB cartridge (60 mg/3 mL). The cartridge was then washed with a 40% methanol aqueous solution (0.5 mL) and eluted with methanol (2 mL). The target compounds were separated on a CORTECS® UPLC® C18 column (100 mm×2.1 mm, 1.6 µm), with methanol and 1 mmol/L ammonium fluoride solution as mobile phases and a flow rate of 0.3 mL/min. Electrospray ionization (ESI) was applied in the positive, negative, and multiple reaction monitoring (MRM) modes for the mass scan. Under optimized conditions, the linear ranges of the 26 targets behaved well linearly in their respective ranges with correlation coefficients (r2)>0.999. The limits of detection (LODs) and limits of quantification (LOQs) were assessed using signal-to-noise (S/N) ratios of 3 and 10, respectively. The LODs and LOQs of the method were 0.01-0.75 µg/kg and 0.02-2.50 µg/kg, respectively. The accuracy of the method was evaluated by conducting a recovery test at three spiked levels: LOQ, two times the LOQ, and 10 times the LOQ, with the average recoveries ranging from 83.7% to 114.9%. The precision of the method was evaluated by using the relative standard deviation (RSD). The intra-day RSDs and inter-day RSDs were 0.86%-9.79% (n=6) and 5.16%-19.5% (n=6), respectively. The established method was used to determine 11 dust samples. Fifteen BPs were detected at a detection rate of 9.1%-100.0%. The detection rate for BPA, BPS, bisphenol F (BPF), 4-hydroxy-4'-isopropoxydiphenylsulfone (BPSIP), and diphenyl sulfone (DPS) was 100.0%. BPSIP, 4-allyloxy-4'-hydroxydiphenyl sulfone (BPS-MAE), and bis-(3-allyl-4-hydroxyphenyl) sulfone (TGSA) were first detected in Chinese dust, whereas 4-benzyloxy-4'-hydroxydiphenyl sulfone (BPS-MPE), 4-hydroxybenzoic acid benzyl (PHBB), and DPS were first detected in dust samples worldwide. This method is simple, rapid, and sensitive, and is suitable for the qualitative screening and quantitative analysis of the 26 BPs in dust samples.

Fluorinated liquid-crystal monomers in paired breast milk and indoor dust: A pilot prospective study.

Fluorinated liquid-crystal monomers (FLCMs), one class of emerging persistent, bioaccumulative and toxic (PBT) compounds, are widely used in liquid-crystal displays (LCDs). As a result, they have been found in the environment and serum from occupational workers. However, little is known about their occurrence in non-occupational exposing populations. Herein, we provided an evaluation of the health risks of FLCMs for infants based on breastfeeding exposure and dust ingestion. The detection frequencies (DF) of FLCMs in indoor dust and breast milk was 100 %, with median concentrations of 12.00 ng/g dry weight (dw) and 133.40 ng/g lipid weight (lw), respectively. 1-butoxy-2,3-difluoro-4-(trans-4-propylcyclohexyl)benzene (BDPrB) was the predominant pollutant in indoor dust and human breast milk. Significant positive correlations were observed between the dust concentrations of seven FLCMs including BDPrB, and their breast milk concentrations (r = 0.275-0.660, P < 0.05). Further, associations were also found in some demographic and behavioral factors and concentrations of some FLCMs (P < 0.05). The highest EDI of ∑FLCMs was observed for infants who were < 1 month of age, with a median breast milk intake of 700.35 ng/kg bw/day, in which 1-ethoxy-2,3-difluoro-4-(trans-4-propylcyclohexyl)benzene (EDPrB), BDPrB, and 4'-[(trans, trans)-4'-butyl[1,1'-bicyclohexyl]-4-yl]-3,4-difluoro-1,1'-biphenyl (BBDB) collectively contributed 94.4 % of the total EDIs. Notably, the lactational intake of FLCMs was higher than that of some environmental pollutants (EPs). Overall, our results suggest higher exposure risks for infants and breastfeeding is the predominant exposure route for daily intake of FLCMs for infants.

Metabolic profiling of the fluorinated liquid-crystal monomer 1-ethoxy-2,3-difluoro-4-(trans-4-propylcyclohexyl)benzene.

1-Ethoxy-2,3-difluoro-4-(trans-4-propylcyclohexyl)benzene (EDPrB) is a typical fluorinated liquid-crystal monomer (LCM). LCMs contaminants are becoming increasingly concerning due to their potential persistence, bioaccumulation, toxicity, and broad prevalence in environmental and human samples. However, LCM metabolism is poorly understood. Herein, by introducing selected EDPrB into the appropriate liver microsomes in vitro, we examined the metabolic pathways of LCM in humans, rats, pigs, Cyprinus carpio, crucian carp, and Channa argus. A total of 20 species-dependent metabolites were identified and structurally elucidated by gas and liquid chromatography-high resolution mass spectrometry for the first time. Dealkylation, H-abstraction, and hydroxylation reactions are the primary metabolic pathways. Half of these in vitro metabolites were found in the urine, serum, and fecal samples of Sprague-Dawley rats exposed to EDPrB. Toxicity predictions indicate that 17 metabolites can be classified as toxic. According to the Ecological Structure Activity Relationships (ECOSAR), a number of metabolites exhibit equivalent or greater aquatic toxicity to that of EDPrB. Toxicity Estimation Software Tool (T.E.S.T.) predicts that some metabolites exhibit developmental toxicity and mutagenicity in rats. These findings suggest that biotransformation should be particularly emphasized, and more toxicological and monitoring studies should be performed to assess the ecological and human safety of LCMs.

Multi-immunoaffinity column for the simultaneous analysis of bisphenol A and its analogues in Chinese foods by liquid chromatography tandem mass spectrometry.

Bisphenol A (BPA) and its four analogues have been receiving considerable attention owing to their potential endocrine disrupting effects. The European Food Safety Authority has proposed 0.04 ng/kg·body weight/day of thetemporary tolerable daily intake for BPA. Therefore, a more sensitive analytical method was urgently needed for the necessity of the risk reassessment of bisphenols (BPs). The matrix effect of Chinese foods is a challenge for the analysis of ultra-trace analytes due to the presence of various spices. A multi-immunoaffinity column (mIAC) was prepared for the purification of BPA, BPB, BPF, BPS, and BPAF in Chinese foods following ultra-high-performance liquid chromatography tandem mass spectrometry detection (UHLPC-MS/MS). The recoveries of each of BPs were ranged from 84.6% to 116.7%, and the intra-day precision and inter-day precision were ranged from 1.6% to 12.4%, and from 4.1% to 14.0%, respectively. This is the first report on the mIACs for simultaneous clean-up and analysis of BPs in complex Chinese foods.

[Determination of 14 paralytic shellfish toxins in plasma and urine by ultra-high performance liquid chromatography-tandem mass spectrometry].

The detection of paralytic shellfish toxins in human biological matrices is important for the diagnosis and treatment of food poisoning caused by them. An ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was established for the determination of 14 paralytic shellfish toxins in plasma and urine. The effect of solid phase extraction (SPE) cartridges was also investigated and the pretreatment and chromatographic conditions were optimized. Under these optimal conditions, 0.2 mL water, 0.4 mL methanol, and 0.6 mL acetonitrile were successively added to plasma and urine samples for extraction. The supernatants from plasma extraction were subjected to an UHPLC-MS/MS analysis, whereas the supernatants from urine extraction were further purified using polyamide (PA) SPE cartridges and then analyzed by UHPLC-MS/MS. Chromatographic separation was conducted on a Poroshell 120 HILIC-Z column (100 mm×2.1 mm, 2.7 µm) with a flow rate of 0.5 mL/min. The mobile phase was 0.1% (v/v) formic acid aqueous solution containing 5 mmoL/L ammonium formate and acetonitrile containing 0.1% (v/v) formic acid. The analytes were detected in the multiple reaction monitoring (MRM) mode after being ionized by an electrospray ion (ESI) in positive and negative modes. Quantitation of the target compounds was performed using the external standard method. Under the optimal conditions, the method showed good linearity in the range of 0.24-84.06 µg/L, with correlation coefficients greater than 0.995. The limits of quantification (LOQs) for the plasma and urine samples were 1.68-12.04 ng/mL and 4.80-34.4 ng/mL, respectively. The average recoveries for all the compounds were 70.4%-123.4% at spiked levels of 1, 2, and 10 times the LOQs, the intra-day precisions were 2.3%-19.1% and the inter-day precisions were 5.0%-16.0%. The established method was used to determine the target compounds in the plasma and urine from mice intraperitoneally injected with 14 shellfish toxins. All 14 toxins were detected in the 20 urine and 20 plasma samples, with contents of 19.40-55.60 µg/L and 8.75-13.86 µg/L, respectively. The method is simple, sensitive, and only requires a small amount of sample. Therefore, it is highly suitable for the rapid detection of paralytic shellfish toxins in plasma and urine.

Occurrence and migration of organophosphite and organophosphate esters into food simulants from single-use food packaging in China.

Organophosphite antioxidants (OPAs) and organophosphate esters (OPEs) are used as additives in food packaging. Because these chemicals have been found in various foods, they have caused increasing concern about potential health risks through food intake. Little information is available about the migration behaviors of OPAs and OPEs from single-use food packaging into food. In the present study, four OPAs and 23 OPEs were analyzed in paper and plastic single-use food packaging (n = 312), which are widely used for take-out food in China. The total concentrations of OPAs and OPEs in the packaging samples were 1966 and 189 ng/g, respectively. Tris (2,4-di-tert-butylphenyl) phosphite (AO168) was the dominant compound. OPAs and OPEs were present at higher concentrations in the plastic packaging than in the paper packaging. In a migration test, four OPAs and 15 OPEs were found in food simulants (4% acetic acid, 10% ethanol, and hexane). Higher levels of individual and total OPAs were found in hexane than the other food simulants, especially for AO168 migration from plastic packaging. The amounts of OPEs in the food simulants increased from the aqueous simulants (4% acetic acid and 10% ethanol) to the fatty food simulant (hexane). The migration efficiencies of the OPAs were higher than those of the OPEs. Preliminary calculations suggest that dietary exposure to OPAs and OPEs because of migration will be low for the population in China.

Identification of key constituent of sugar-smoking pigment and its photobleaching, antioxidant and antiproliferative properties.

The key constituent(s) of sugar-smoking brown pigments were identified, the chemical and biological properties were subsequently investigated, and the possibility of obtaining it from nature was explored. A pigment was isolated, which was identified as condensation product of 5-hydroxymethyl-2-furfuraldehyde (5-HMF) with glucose: 5-(α-D-glucopyranosyl-(1-6)-α-D-glucopyranosyloxymenthyl)-2-furancarboxaldehyde (5-GGMF). The molecular weight was 450.00. The interaction between pigment with protein on chicken skin was mainly via hydrogen and carbon-hydrogen bonds. It was obtained by caramelization instead of Maillard reaction. Discoloration of sugar-smoking pigments were mainly due to cleavage of chromophores caused by the oxidation reaction followed by photobleaching mechanism. Both radical scavenging and antiproliferative capacity of sugar-smoking pigment were in a dose-dependent manner. However, the IC50 values for HepG2 and PANC-1 cells differed by more than ten times. Since 5-GGMF is also present in plant resources (like Rehmanniae Radix), it can be obtained as natural additive to produce clean label sugar-smoked meat products.