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EU-China-Safe: Delivering an Effective, Resilient and Sustainable EU-China Food Safety Partnership
Similar articles Cited by MeSH terms Substances Related information LinkOut-more resources. Abstract Lung cancer is a common cancer with high mortality worldwide, and non-small cell
1. Recruitment of Chinese students to study online at European universities using social media chatbots in China. 2. Creating a personal online contact of a Chinese student with a European educational institution through an automatic AI translator. 3. Translation of all materials of the educational course into Chinese through AI linguistic resources (audio to text and text to audio). 4. The use of AI direct communication between the student and the teacher with participation through the AI automatic voice translator. 5. Assigning of a personal mentor to the student - a native speaker of Chinese, who helps in learning and working with AI. 6. Automatic testing programs based on learning outcomes based on AI. 7. AI assistance in obtaining international grants for education. 8. Assistance in obtaining invitations for internships at the UN and other international organizations.
The copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) click reaction has drawn increasing attention in the field of analytical science. However, the poor stability of Cu(I) usually hinders not only the simplicity of the click reaction but also its applications in precise analyses. Therefore, the development of a nanocatalyst containing stable Cu(I) is of great significance for broadening the application of CuAAC-based assays. Herein, inspired by the active center structure of natural multicopper oxidases (MCOs), we successfully prepared a novel nanocatalyst containing abundant stable Cu(I) as an artificial "clickase" (namely, CCN) by using glutathione to stabilize Cu(I). The stability and enzyme-like catalytic activity in the CuAAC reaction of the prepared CCN clickase were studied, and the catalytic mechanism of the CCN clickase-mediated CuAAC reaction between 3-azide-7-hydroxycoumarin (Azide 1) and propargyl alcohol (Alkyne 2) was also revealed. Compared with the existing solid CuO nanocatalysts used in CuAAC-based assays, CCN clickases exhibited plenty of superior properties (including high stability, excellent catalytic activity, no requirements of dissolution and reducing agents/radical initiator during the detection, well-defined porosities benefiting the substrate diffusion, and good biocompatibility), which can greatly increase the reaction efficiency and shorten the detection time. Encouraged by these remarkable performances, CCN clickases were used as labels to establish a new catalytic click fluorescence immunoassay for foodborne pathogens. Notably, the proposed CCN clickase-based immunoassay exhibited high analytical performances for the quantification of Salmonella enteritidis in the linear range of 102-106 CFU/mL with a limit of detection as low as 11 CFU/mL. The developed method has also been used in the determination of S. enteritidis in food samples, showing its great potential in the detection of foodborne pathogens.
Correction for ‘Emerging per- and polyfluoroalkyl substances (PFAS) in human milk from Sweden and China’ by Raed Awad et al. , Environ. Sci.: Processes Impacts , 2020, 22 , 2023–2030, DOI: 10.1039/D0EM00077A.
Persistent organic pollutants (POPs) remain a major point of concern worldwide, and surveillance monitoring of these contaminants presents a significant challenge. Here, we conducted an assessment of combined exposure to multiple POPs components [10 perfluoroalkyl acids (PFAAs), seven polybrominated diphenyl ethers (PBDEs), six polychlorinated biphenyls (PCBs) and 29 dioxin-like compounds (DLCs)] in relation to gestational diabetes mellitus (GDM) risk, and determined the identification and prioritization of potent components in these POPs mixtures. The results indicated a significant mixture effect and the combined exposure index estimated from multiple POPs components was associated with GDM and glucose homeostasis (P < 0.001). Based on the mixture effects on GDM, the procedure of prioritization identified DLCs as the components of the greatest concern, although at the lowest body burden in the population compared with PBDEs, PFAAs, and PCBs. For glucose homeostasis, BDE-153 was the chemical of top-ranked priority of concern. The final effect-based prioritized list of POPs was DLCs > PBDEs >PFAAs > PCBs. This prioritization is important for developing a more cost-effective regulation framework focusing on the POPs components of the greatest concern to human health.
Mycotoxins, a toxic secondary metabolite, unpredictably, and unavoidably occur in foods and feeds, leading to adverse health impacts and enormous economic losses in the agriculture industry. Moreover, mycotoxin contamination has been a great threat for the public health and agriculture economy development worldwide. Therefore, the control of the mycotoxin contamination is of great importance and has caused rising concern worldwide. Recently, emerging nanomaterials have been promisingly applied in the control of mycotoxin contamination and have obtained many achievements. In this review, first of all, the type, occurrence, and toxicity of mycotoxins are simply discussed. Then, attentions are focused on the applications of emerging nanomaterials to controlling the mycotoxin contamination, including mycotoxin assay, the inhibition of mycotoxin production, the adsorption of mycotoxins, and mycotoxin elimination. In the end, the future opportunities and challenges on the toxicity, occurrence, and control of mycotoxins are tentatively put forward. Emerging nanomaterials for mycotoxin detection, production inhibition, adsorption, and elimination.
Primary Toxoplasma gondii infection in pregnant women may result in abortion, stillbirth, or lifelong disabilities of the unborn child. One of the main transmission routes to humans is consumption of raw or undercooked meat containing T. gondii tissue cysts. We aim to determine and compare the regional distribution of T. gondii seroprevalence in pregnant women and meat-producing livestock in China through a systematic literature review. A total of 272 eligible publications were identified from Medline, Scopus, Embase and China National Knowledge Infrastructure. Apparent and true seroprevalence were analysed by region using a novel Bayesian hierarchical model that allowed incorporating sensitivity and specificity of the applied serological assays. The true seroprevalence of T. gondii in pregnant women was 5.0% or less in seven regions of China. The median of the regional true seroprevalences in pigs (24%) was significantly higher than in cattle (9.5%), but it was not significantly higher than in chickens (20%) and small ruminants (20%). This study represents the first use of a Bayesian hierarchical model to obtain regional true seroprevalence. These results, in combination with meat consumption data, can be used to better understand the contribution of meat-producing animals to human T. gondii infection in China.
Perfluorinated compounds (PFCs) are ubiquitous in the environment and are becoming a public health concern. It is desirable to develop sensitive and accurate methods to measure PFCs in non-invasive matrices such as hair and nail for biomonitoring of body burden. Different extraction methods coupled with solid phase extraction were investigated for extraction efficiency. The extracts were separated, identified and quantified by liquid chromatography-tandem mass spectrometry. Extraction with acetonitrile proved to be the most efficient extraction method for human hair sample, while extraction by methanol with alkaline digestion performed best for human nail sample. The matrix recoveries of the optimized methods ranged from 78% to 116% for hair and from 87% to 126% for nail sample. The ranges of the limit of detection (LOD) were 0.026-0.069 ng/g and 0.023-0.094 ng/g for hair and nail, respectively. These methods were validated by evaluating LOD, accuracy and precision and were proven to be useful for measuring paired human hair and nail samples collected from the general population.
Perfluoroalkyl substances (PFASs) have been distributed in environment and human body worldwide. Due to their bioaccumulative and multiple organ toxic, these compounds have raised more and more attention in recent years. The precursors of PFASs can be metabolized to PFASs both in environment and human body, which makes an important contribution to human body burdens. Apart from transformation into PFASs, some of these precursors themselves or their metabolic intermediates also have toxicity effects, such as estrogen-like properties, protein binding, cytotoxicity and so on, and there might be a potential harmful impact on human health. In this paper, the toxicity and biotransformation of PFASs and their precursors were introduced briefly.
In this study, a highly sensitive and fast method of QuEChERS (acronym of quick, easy, cheap, effective, rugged, safe) combined with isotope dilution–ultra performance liquid chromatography coupled to tandem mass spectrometry was developed for the simultaneous determination of 19 plant growth regulators in plant-originated foods. The samples were initially extracted with acetonitrile containing 1% acetic acid and then the QuEChERS method was applied after the pH value was adjusted to 5.5 – 6.0, using 3-indolepropionic-d2 acid and forchlorfenuron-d5 as internal standard. The targeted 19 plant growth regulators were separated on an HSS T3 column using acetonitrile: 5 mmol/L ammonium acetate as the mobile phase. Quantitative results were based on multiple reaction monitoring mode after ionization in positive and negative electrospray ionization mode. Good linearity was achieved within a wide range and all the correlation coefficients were greater than 0.997. The limit of quantification was 0.060 – 6.0 μg/kg. Rate of recovery and relative standard deviation were 72.3 – 115.8 and 1.78 – 5.32%, respectively. The method was successfully applied to measure 19 plant growth regulator residues in 280 plant-originated commercial foods collected from local supermarkets in China. Twelve plant growth regulators were found in some of the analyzed samples.
Seven congeners of polybrominated diphenyl ethers (PBDEs) (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153,BDE-154 and BDE-183) and six indicator polychlorinated biphenyls (PCBs) (PCB-28, PCB-52, PCB-101, PCB-138, PCB-153 and PCB-180) were measured in 32 regional pooled human milk samples originating from 1760 volunteering primiparous mothers to evaluate the current human body burden of general population and the temporal trend in China. Individual human milk samples were collected following a WHO-designed procedure. This work is one of parts of the evaluation of effectiveness of Stockholm Convention performance. The concentration of ∑7PBDEs ranged from 0.3 ng g(-1) lipid to 4.0 ng g(-1) lipid with a mean of 1.5 ng g(-1) lipid. The concentration of ∑6PCBs ranged from 2.3 ng g(-1) lipid to 19.0 ng g(-1) lipid with a mean of 6.6 ng g(-1) lipid. By comparing with background determination in 2007, there was no significance for ∑7PBDEs. However, BDE-47, BDE-99, and BDE-100 significantly decreased with an average of 45%, 48%, and 46%, respectively, from 2007 to 2011, and an increase of BDE-183 was founded in most regions. For ∑6PCBs, there was a significant decline with an average reduction of 41% from 2007 to 2011. These results indicate the effectiveness of reduction and elimination of POPs in China. Future national human milk biomonitoring is worthy to be done to further evaluate the time trend and effectiveness of the Convention performance.
Impact Factor: 3.11 dx.doi.org/10.1021/jf2039058 A sensitive method has been developed for the simultaneous determination of residues of 25 β2-agonists and 23 β-blockers in animal foods by high-performance liquid chromatography coupled with linear ion trap mass spectrometry (HPLC- LIT-MS). This method is based on a new procedure of hydrolysis and extraction by 5% trichloracetic acid, and then cleaned up by mixed strong cation exchange (MCX) cartridges coupled with a novelty cleanup step by methanol. Methanol and 0.1% formic acid were used as mobile phases for gradient elution, while a Supelco Ascentis Express Rp-Amide column was used for LC separation. ESI positive ion scan mode was used with consecutive reaction monitoring (CRM, MS3). Nine β2-agonists labeled by the deuterium isotope were used as internal standards for quantification. The linear ranges of 48 analytes were from 5 to 200 μg/L; the coefficient of correlation was not less than 0.995. Blank pork muscle, blank liver, and blank kidney were selected as representative matrix for spiked standard recovery test. The recoveries of each compound were in the range of 46.6−118.9%, and the relative standard deviations were in the range of 1.9−28.2%. Decision limits (CCα, α = 0.01) of 48 analytes in muscles, liver, and kidney samples ranged from 0.05 to 0.49 μg/kg, and the detection capability (CCβ, β = 0.05) ranged from 0.13 to 1.64 μg/kg. This method was successfully applied to 110 real animal origin food samples including meat, liver, and kidney of pig and chicken samples.
The authors describe a colorimetric method for the determination of ultra-trace levels of uranyl ion (UO2²⁺) in beverage and milk. It employs (a) DNAzyme-functionalized magnetic beads (MBs) for UO2²⁺ recognition, (b) horseradish peroxidase (HRP)-assisted catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) for signal generation, and (c) rolling circle amplification (RCA) for sensitivity improvement. The employment of DNAzyme-functionalized MBs facilitates the separation and collection of analyte from sample matrix. This results in more convenient operation, better selectivity and more strong resistibility to sample matrix. The RCA strategy realizes one UO2²⁺-to-massive HRP effect, which strongly improves the sensitivity. The method has outstanding advantages including high sensitivity, convenient operation, strong resistibility to complex matrix, and good selectivity. It can be used to detect as low as 20.0 pg·mL⁻¹ (74 pmol·L⁻¹) of UO2²⁺ in milk and beverage by bare eye observation. Even lower concentrations (1.0 pg·mL⁻¹ or 3.7 pmol·L⁻¹) of UO2²⁺ can be detected with the method via UV-visible spectrometry at 650 nm. The method was applied to analyze spiked samples and gave recoveries of 98 to 105% and RSDs of ±7% (n = 6). The visual detection limit is much lower than the maximum allowable level of UO2²⁺ in drinking water as defined by the Environmental Protection Agency of USA. This indicated that the method meets the requirement of simple, rapid and on-site detection of ultra-trace UO2²⁺ in milk and beverage. Graphical abstractA colorimetric assay was developed for the rapid and visual detection of trace UO2²⁺ in beverage and milk by employing (a) DNAzyme-functionalized magnetic beads (MBs) for UO2²⁺ recognition, (b) horseradish peroxidase-assisted catalytic oxidation of 3,3′,5,5′-tetramethylbenzidine sulfate (TMB) for signal generation, and (c) DNA rolling circle amplification (RCA) reaction for signal amplification.
A comprehensive analytical method based on gas chromatography-mass spectrometry (GC-MS) has been developed for the simultaneous determination of 8 polybrominated biphenyl congeners (PBBs: BB-15, 18, 52, 101, 153, 180, 194 and 206) in human serum. After the protein was removed, the sample was cleaned-up by an Oasis HLB solid-phase extraction (SPE) cartridge, then purified further by a two-layer cartridge containing activated silica gel and a mixture of silica gel and sulfuric acid, in which elution solvent was optimized. The eluent was evaporated to about 100 microL by a gentle nitrogen stream for GC-MS analysis. The separation was performed on a DB-5ms column (15 m x 0.25 mm x 0.1 microm) and the qualitative and quantitative analyses were carried out in electron impact (EI) selected ion monitoring (SIM) mode, in which isotope was used as internal standard. The limits of detection (LODs, 3.14 times of standard deviation) and the limits of quantification (LOQs, 10 times of standard deviation) were 0.002-0.029 ng/mL and 0.008-0.092 ng/mL respectively for the 8 PBBs. The average recoveries for all PBBs at three spiked levels were 74.24%-119.49% with the relative standard deviations in the range of 1.23%-12.02%. The method was verified by accurate analysis of BB-153 in organic contaminant standard reference materials (SRM) 1957 and 1958. This method is simple, rapid, accurate, precise and fit for the determination of PBBs in human serum.
A method was developed for determination of 8 species of unauthorized drugs in bovine milk by liquid chromatography-tandem mass spectrometry (LC-MS/MS). All target drugs covered 5 nitro- imidazoles, 7 β-agonists, 9 androgens, 7 glucocorticoids, 3 estrogens, 2 sedatives, 1 chloramphenicol and 6 resorcylic acid lactones. After homogenization, the sample was mixed with β-glucuronidase/ arylsulfatase for enzymatic reaction in ammonia acetate bufer and folowed by extraction with basic and then acidic acetonitrile solutions.Cleanup ofthe extracts was proces sed by a modified dispersive solid phase extration(QuEChERS). The analystes were then separated by a C18 column (150 mm× 2 .1 m m i.d .,3 .0 m m ) utilising gradient elution with methanol/water (containing 0 .1 % formic acid ) and acetontrile/water, and finally detected by tandem mass spectrometry in positive/negative ESI mode . Identification and quantification were achieved by LC- MS/MS with multi-reaction monitoring . Isotope internal standards for 7 compounds and matrix-matched calibrations were respectively used to quantify the residue contents. Good linearity in response was obtained in the concentration range of 0.02-0.40 mg/kg for chloramphenicol and 0.20-10.0 mg/kg for the other 39 analytes, with correlation coefficients larger than 0.99. The limits of quantification (S/N =10) was around 0.07-0.93 mg/kg. Method validation was caried out at half minimum required performance limits (MRPL), MRPL and double MRPL level of each substance, and the recoveries were in the range of 60.3%-119.3% with relative standard deviations (RSD ) smaller than 18 .9 % .
Background: Inappropriate use of antibiotics in swine feed could cause accelerated emergence of antibiotic resistance genes, and agricultural application of swine waste could spread antibiotic resistance genes to the surrounding environment. Objectives: We investigated the distribution of plasmid-mediated quinolone resistance (PMQR) genes from swine feedlots and their surrounding environment. Methods: We used a culture-independent method to identify PMQR genes and estimate their levels in wastewater from seven swine feedlot operations and corresponding wastewater-irrigated farm fields. Concentrations of (fluoro)quinolones in wastewater and soil samples were determined by ultra-performance liquid chromatography–electrospray tandem mass spectrometry. Results: The predominant PMQR genes in both the wastewater and soil samples were qnrD, qepA, and oqxB, whereas qnrS and oqxA were present only in wastewater samples. Absolute concentrations of all PMQR genes combined ranged from 1.66 × 107 to 4.06 × 108 copies/mL in wastewater and 4.06 × 106 to 9.52 × 107 copies/g in soil. Concentrations of (fluoro)quinolones ranged from 4.57 to 321 ng/mL in wastewater and below detection limit to 23.4 ng/g in soil. Significant correlations were found between the relative abundance of PMQR genes and (fluoro)quinolone concentrations (r = 0.71, p = 0.005) and the relative abundance of PMQR genes in paired wastewater and agricultural soil samples (r = 0.91, p = 0.005). Conclusions: Swine feedlot wastewater may be a source of PMQR genes that could facilitate the spread of antibiotic resistance. To our knowledge, this is the first study to examine the occurrence of PMQR genes in animal husbandry environments using a culture-independent method.
A room temperature ionic liquids (RTILs) matrix-assisted desorption corona beam ionization (DCBI) technique was proposed. The quantification of the DCBI method for low-polar small molecules was improved greatly in terms of accuracy and precision. The thermal desorption processes of analytes in different liquid matrices under DCBI interrogation was investigated with thermal imaging and mass spectrometry simultaneously. When in a volatile liquid matrix, the analyte was not only desorbed thermally from the solid residue phase, but also desorbed along with evaporation of the matrix. The varying matrix evaporation speed and unstable sample introduction path clearly influence the quantitative result. With non-volatile RTILs utilized as the matrix in the sample introduction, a micro slow release system (MSRS) is formed to relieve the fluctuation of analyte evaporation. With the RTILs matrix-assisted DCBI-MS technique, dramatic improvement of the quantification precision (RSD from about 20% to less than 3%) for model analytes was achieved. Seventeen small pharmaceutical and four pesticide molecules were detected successfully. With a shared mechanism, other thermal desorption and/or APCI-related ambient ionization techniques may also benefit from the RTILs matrix.
To establish a method of combining gas chromatography-mass spectrometry (GC-MS) with head-space solid phase micro-extraction (HS-SPME) for the detection of 2,4,6-trichloroanisole (2,4,6-TCA) in wine. 2,4,6-TCA in wine were extracted by polydimethylsiloxane (PDMS,100 microm) fiber for 15 min under 35 degrees C in a water bath. The fiber was then transferred into the injection port of the GC-MS and separated by a CP-SIL 8CB-MS capillary column (30m x 0.25mm x 0.25 microm), and detected by mass spectrometry using d5-2,4,6-TCA as an internal standard. The linear range for 2,4,6-TCA was 5 (60ng/L, the detection limit was 0.06ng/L. The recovery of standard addition (5, 10, 20ng/L) was in the range of 79.8% (101.6% with relative standard deviations (RSD, n=5) < or = 7%. Organic solvents were avoided and the selection was sensitive for the method, which is suitable for the determination of 2,4,6-TCA in wine.
Desorption corona beam ionisation (DCBI), the relatively novel ambient mass spectrometry (MS) technique, was utilised to screen for illicit additives in weight-loss food. The five usually abused chemicals - fenfluramine, N-di-desmethyl sibutramine, N-mono-desmethyl sibutramine, sibutramine and phenolphthalein - were detected with the proposed DCBI-MS method. Fast single-sample and high-throughput analysis was demonstrated. Semi-quantification was accomplished based on peak areas in the ion chromatograms. Four illicit additives were identified and semi-quantified in commercial samples. As there was no tedious sample pre-treatment compared with conventional HPLC methods, high-throughput analysis was achieved with DCBI. The results proved that DCBI-MS is a powerful tool for the rapid screening of illicit additives in weight-loss dietary supplements.
To determine 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) residues released from protein bound AMOZ in animal tissues. Polyclonal and monoclonal antibodies were produced in this study. A rapid, sensitive, and specific competitive direct enzyme-linked immunosorbent assay (cdELISA) was developed. Rabbit polyclonal antibodies were used in the optimized cdELISA method, and exhibited negligible cross-reactivity with other compounds structurally related to AMOZ. The IC(50) of the polyclonal antibody was 0.16 ng/mL. The method limit of detection in four different types of animal and fish tissues was less than 0.06 μg/kg. Recoveries ranged from 80% to 120% for fortified samples with the coefficient of variation values less than 15%. The results of the cdELISA method were in good agreement with the results from an established liquid chromatography-tandem mass spectrometry confirmatory method used for AMOZ residues. The cdELISA method developed in the present study is a convenient practical tool for screening large numbers of animal and fish tissue samples for the the detection of released protein bound AMOZ residues.
The investigations and optimizations of removing pigments from tea extract were accomplished by using iron oxide nano. particles (MNPs) for the pesticide residues analysis. A novel type of hybrid solid phase extraction cartridge, which contains MNPs, anhydrous magnesium sulfate and GCB, was developed. The analytical results demonstrated that the novel solid phase extraction (SPE) cartridge was better than commercial QuEChERS on the purification efficiency. Because the cost of MNPs was much lower than that of N-propyl ethylene diamine (PSA), the experiment cost savings of the newly developed hybrid solid phase extraction column were also effective. The samples were analyzed by GC. MS after hybrid solid phase extraction cartridge purify, the validation result revealed that the recoveries of 16 kinds of pesticides were between 80% -114%, the limits of detection were bellow 0.030 mg/kg, and the RSDs were between 1.4% and 11.5%. The recovery proved that the hybrid solid phase extraction method was as good as commercial QuEChERS method. In addition, the SPE method showed better pigments removing ablility than QuEChERS and cost-saving.
Because of the disadvantages of invasive sampling, it is desirable to explore non-invasive matrices for human biomonitoring of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). The aim of this study was to evaluate the application of nail, hair and urine for human biomonitoring of PFOS and PFOA. The concentrations of PFOS and PFOA in matched nail, hair, urine and serum samples collected from 64 donors were measured. The chemicals of interest were detected with high detection frequency in these matrices (90%-100%) except for PFOA in urine samples (56%). Generally, the gender influences on the levels of PFOS and PFOA in these non-invasive matrices were in agreement with that in serum. For PFOS, the coefficients of Spearman correlation between serum samples and nail, hair and urine samples were 0.786 (p<0.001), 0.545 (p<0.001) and 0.302 (p<0.05), respectively. For PFOA, the correlation was only observed between nail samples and serum samples with a correlation coefficient of 0.299 (p<0.05). The results suggested that nail has more potential than hair and urine to be applied in human biomonitoring for PFOS and PFOA in general populations.
A new method for the determination of fatty acid mono- and diesters of monochloropropanediol (MCPD) was developed. The isotopically labelled standard solution was added to the sample solution and adsorbed on the aminopropyl column. Then MCPD diesters were eluted by 6. 0 mL n-hexane and MCPD monoesters were eluted by a 6. 0 ml mixture of n-hexane/ethylacetate (7:3, V/V). The concentratrated elution were hydrolyzed with methoxide and derivatizated with phenylboronic acid (PBA) before GC/MS analysis. The method was precise and sensitive, the limits of detection for MCPD monoesters and MCPD diesters were 83. 0 mu g/kg and 142 mu g/kg, respectively. There was an excellent linear correlation (R-2 > 0. 9990) in the range of 25-500 mu g/L of MCPD monoesters & diesters (calculated by MCPD). The recovery rate of MCPD fatty acid esters spiked into edible oil and infant formula samples was in the range of 86. 5% - 104. 0%. The relative standard deviation (RSD) was from 2. 4% to 13. 2%. The method was successfully applied to the analysis of commercial edible oils and infant formula samples.
The intake of N-nitrosamines (NAs) from foodstuffs is considered to be an important influence factor for several cancers. But the rapid and sensitive screening of NAs remains a challenge in the field of food safety. Inspired by that, a sensitive and rapid method was demonstrated for determination of five NAs (Nitrosopyrrolidine, Nitrosodimethylamine, Nitrosodiethylamine, Nitrosodipropylamine and Nitrosodibutylamine) using dispersive liquid–liquid microextraction (DLLME) followed by high-performance liquid chromatography with fluorescence detection (HPLC–FLD). The NAs were firstly denitrosated and labeled by 2-(11H-benzo[a]carbazol-11-yl) ethyl carbonochloridate (BCEC-Cl) and finally enriched by DLLME. Furthermore, the main DLLME conditions were optimized systematically. Under the optimal conditions, satisfactory limits of detection (LODs) were obtained with a range of 0.01-0.07 ng g⁻¹, which were significantly lower than the reported methods. The developed method showed many merits including rapidity, simplicity, high sensitivity and excellent selectivity, which shows a broad prospect in food safety analysis.
A national survey of three currently used brominated flame retardants (BFRs), tetrabromobisphenol A (TBBPA), hexabromocyclododecane (HBCD) and decabrominated diphenyl ether (BDE-209) in human milk was conducted in 2011. Human milk from 16 provinces of China were collected, pooled and measured. The estimated daily intake (EDI) via human milk ingestion for nursing infant and the related health risks were evaluated. The median levels of TBBPA, HBCD and BDE-209 were 1.21, 6.83 and 0.556 ng/g lipid weight (lw), respectively. Levels of BDE-209 were lower than those of TBBPA, indicating that the production and application of deca-BDE in China has been below that of TBBPA after the restriction of PBDEs. Moreover, contamination levels of TBBPA and HBCD in this survey were higher than those observed in last national survey conducted in 2007, indicating an increase of TBBPA and HBCD in the environment from 2007 to 2011. The mean estimated daily intakes (EDIs) of TBBPA, HBCD and BDE-209 via human milk for 1–6 months old infant were 39.2, 51.7 and 3.65 ng/kg bw/day, respectively. For risk assessment, margin of exposure (MOE) was calculated by comparing the BMDL10 (benchmark dose lower confidence limit for a benchmark response of 10%) to the EDI of each BFR. Large MOEs indicates that the estimated dietary exposure to these three BFRs for nursing infant is unlikely to raise significant health concerns. Compared with some currently used novel BFRs which also measured in this survey, higher contamination levels were found in some non-PBDE BFRs, indicating that the consumption pattern of BFRs has shifted from PBDEs to non-PBDE BFRs in China.
Enzyme-linked immunosorbent assays (ELISAs) usually focus on the detection of a single analyte or a single group of analytes, e.g., fluoroquinolones or sulfonamides. However, it is often necessary to simultaneously monitor two classes of antimicrobial residues in different food matrices. In this paper, we describe a dual-colorimetric ELISA for the simultaneous detection of 13 fluoroquinolone and 22 sulfonamide residues. The limit of detection for fluoroquinolones and sulfonamides was 2.4 ng/mL and 5.8 ng/mL, respectively. The developed immunoassay is suitable for high-throughput screening of these low-molecular weight contaminants. This is the first report where two different enzymes (alkaline phosphatase and horseradish peroxidase) were used in one immunoassay and together in a single well for simultaneous detection of multiple low-molecular weight chemical residues.
Metallo-β-lactamase gene blaVIM was identified on the chromosome of four Pseudomonas spp. isolates from a chicken farm, including one P. aeruginosa from swallow ( Yanornis martini ), one P. putida from fly, and two P. putida from chickens. The four isolates shared two variants of blaVIM -carrying genomic contexts, which resemble the corresponding regions of clinical MBL-producing Pseudomonas species. Our study suggests the surveillance of carbapenemase-producing bacteria in livestock and their surrounding environment is urgently needed.
When dealing with food fraud, most consumers are concerned with economically motivated adulteration (EMA), which is one of the important factors that affect and undermine food safety, and food security, and may cause disturbance of society stability. Food fraud is the top issue for Chinese food safety legal and regulatory activities. This chapter gives some examples of typical food fraud incidents in China. Food fraud management and response is a systematic project involving multiple levels of legal, institutional, and technological coordination. For the detection of fraud in functional foods that involves prohibited substances, liquid chromatography, and liquid chromatography-mass spectrometry are the main methods used. Rapid detection devices have become effective means of speedy customs clearance of food and on-site food safety enforcement. Such detection devices based on antibody libraries and immunological techniques will be increasingly indispensable to internal inspections at food producers and regulatory inspections.
To study the application of international intercalibration study in quality assurance and control (QA/QC) by the analysis of our laboratory' s results from interlaboratory comparison on dioxins in foods from 2005-2012. Z-scores were used to appraise the results from the interlaboratory comparison on dioxins in foods organized by Norwegian Institute of Public Health, and analyze the determination of PCDD/Fs and dl-PCBs in various foods. The absolute values of z-score of concentrations of PCDD/Fs and dl-PCBs in almost all foods determined by our laboratory are were all less than 1, indicating excellent results. The international intercalibration study is a greatly effectively approach of QA/QC. Thus, qualified laboratories should be encouraged more involved in international comparison to improve the detection ability and the reliability of the results.
Background Haff disease is unexplained rhabdomyolysis caused by consumption of fishery products in the previous 24 h. It was first identified in Europe in 1924 but the condition is extremely rare in China. Here we describe a past outbreak of acute food borne muscle poisoning that occurred in Guangdong Province (South China) in 2009. Methods The first full outbreak of Haff disease reported in Jiangsu Province (East China) in 2010, indicated that the incidence of the disease may be increasing in China. We, therefore first retrospectively reviewed epidemiologic, trace-back, environmental studies, and laboratory analyses, including oral toxicity testing to ascertain risk and chemical analysis to identify toxin(s), from the 2009 Guangdong outbreak. Then we compared data from the 2009 outbreak with data from all other Haff disease outbreaks that were available. Results Clinical symptoms and laboratory findings indicated that the 2009 Guangdong outbreak disease was consistent with rhabdomyolysis. Epidemiologic, trace-back, environmental studies and laboratory analyses implied that the disease was caused by freshwater Pomfrets consumed prior to the onset of symptoms. We also identified common factors between the 2009 Guangdong outbreak and previous Haff disease outbreaks reported around the world, while as with other similar outbreaks, the exact etiological factor(s) of the disease remains unknown. Conclusions The 2009 Guangdong outbreak of ‘muscle poisoning’ was retrospectively identified as an outbreak of Haff disease. This comprised the highest number of cases reported in China thus far. Food borne diseases emerging in this unusual form and the irregular pattern of outbreaks present an ongoing public health risk, highlighting the need for improved surveillance and diagnostic methodology.
Background Acute gastrointestinal illness (AGI) is an important public-health problem worldwide. Previous national studies of the incidence of AGI in China were performed decades ago, and detailed information was not available. This study therefore sought to determine the magnitude, distribution, and burden of self-reported AGI in China. Methods Twelve-month, retrospective face-to-face surveys were conducted in 20 sentinel sites from six provinces between July 2010 and July 2011. Results In total, 39686 interviews were completed. The overall adjusted monthly prevalence of AGI was 4.2% (95% confidence interval, 4.0–4.4), corresponding to 0.56 episodes of AGI per person-year. Rates of AGI were highest in children aged < 5 years. Healthcare was sought by 56.1% of those reporting illness. Of the cases who visited a doctor, 32.7% submitted a stool sample. The use of antibiotics was reported by 49.7% of the cases who sought medical care and 54.0% took antidiarrhoeals. In the multivariable model, gender, age, education, household type, residence, season, province and travel were significant risk factors of being a case of AGI. Conclusions This first population-based study in China indicated that AGI represents a substantial burden of health. Further research into the specific pathogens is needed to better estimate the burden of AGI and foodborne disease in China.
Immunoassays contribute greatly to food safety. But there are no reported immunoassays that simultaneously detects MQCA and QCA, the marker residues for olaquindox and carbadox, respectively. Here a broad-specificity MAb was successfully produced, and the MAb showed good cross-reactivity with both MQCA and QCA, having IC50 values in buffer of 4.8 and 9.6 ng/mL, respectively. The calibration curves ranged from 0.3 to 81 μg/kg. The average recoveries ranged from 76 to 108% at different spiked levels (2, 4, and 8 µg/kg for MQCA; and 4, 10, and 20 µg/kg for QCA), and the intra/inter-day coefficient of variations were 4.2-13.3%. The limits of detection of MQCA and QCA in chicken, fish, pork, and shrimp were 1.76, 1.32, 1.90, and 1.18 µg/kg, respectively. This method was verified by LC-MS/MS, with a correlation coefficient above 0.98. The immunoassay was rapid and reliable for simultaneous screening analysis of MQCA and QCA residues.
A high performance liquid chromatography-fluorescence detection (HPLC-FLD) method was established for rapid determination of ethyl carbamate (EC) in Chinese spirits. Through the analysis and comparison of the EC peak areas in different alcoholic strengths determined by HPLC-FLD, the effect of alcoholic strength on the determination of the content of EC was found. The alcoholic strength and the peak area of EC showed good linearity in the range of 5% to 65% (v/v) alcohol content, and the correlation coefficients (R2) were higher than 0.98. Furthermore, the conversion between the peak area of EC with different alcoholic strengths was established by the relative correction coefficient. The method showed a good linearity in the range of 10 to 500 microg/L for EC with the average recoveries of 98.9%-108.2% and RSDs of 0.6%-4.9%. The reliability of the established HPLC-FLD method was evaluated by comparison with GC-MS method. The results showed that the results of two methods were not significantly different. The developed method is simple, sensitive, accurate, and suitable for the rapid determination of EC in Chinese spirits.
A liquid chromatography-linear ion-trap spectrometry (LC-MS(3)) method using β-receptor molecular-imprinted polymer (MIP) solid-phase extraction (SPE) as clean-up was developed to determine simultaneously and confirmatively residues of 25 β2-agonists and 21 β-blockers in urine samples. Urine samples were subjected to enzymatic hydrolysis by β-glucoronidase/arylsulphatase, and then extracted with perchloric acid. Sample clean-up was performed using β-receptor MIP SPE. A Supelco Ascentis(®) express Rp-Amide column was used to separate the analytes, and MS(3) detection used an electrospray ionisation source in positive-ion mode. Recovery studies were carried out using blank urine samples fortified with the 46 analytes at the levels of 0.5, 1.0 and 2.0 μg l(-1). Recoveries were obtained ranging from 60.1% to 109.9% with relative standard deviations (RSDs, n = 7) from 0.5% to 19.4%. The limits of detection (LODs) and limits of quantitation (LOQs) of the 46 analytes in urine were 0.02-0.18 and 0.05-0.60 μg l(-1), respectively. As a result of the selective clean-up by MIP SPE and MS(3) detection of the target drugs, the sensitivity and accuracy of the present method was high enough for monitoring β2-agonist and β-blocker residues in urine samples. Satisfactory results were obtained in the process of the determination of positive urine samples.
Total mercury (THg) levels in 440 pairs of milled rice samples and brown rice samples from 15 major rice grain-producing provinces of China were measured and the associated health risk via rice consumption for different age categories of Chinese population was also assessed. THg contents were measured by a direct mercury analyser and the limit of detection (LOD) was 1.5 μg kg(-1). The THg levels for milled rice samples and brown rice samples varied from non-detected to 17.8 μg kg(-1) and 1.5 to 25.4 μg kg(-1), respectively, with a mean level of 3.4 μg kg(-1) and 4.9 μg kg(-1), respectively. The THg levels in all milled and brown rice samples were generally low, except three brown rice samples having concentrations above the legally set value for cereals (20 μg kg(-1) Hg). THg intakes for different age categories were estimated according to THg content and corresponding rice consumption and the associated health risk was evaluated by the corresponding provisional tolerable weekly intake (PTWI) for THg (5.0 μg kg(-1) bw week(-1)), which was established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The 50th percentile of the THg intakes via milled rice and brown rice consumption for different age categories was in the range 0.09-0.19 μg kg(-1) bw week(-1) and 0.14-0.27 μg kg(-1) bw week(-1), respectively, well below the PTWI, suggesting that the associated health risk is relatively low. However, the 99.9th percentile of the THg intakes for 2-4-year-old children amounted up to 20.6% of the PTWI (milled rice) and 29.5% of the PTWI (brown rice), which deserves attention.
A rapid, simple and selective method based on molecularly imprinted, spin column extraction coupled with fluorescence detection was successfully established for the determination of 2,4-dinitrophenol in serum samples. The 2,4-dinitrophenol imprinted polymers exhibited highly selective recognition for the template molecule and the maximum adsorption capacity was 138.9 mg/g. The results indicated that when water is used as the loading solution, only 2,4-dinitrophenol could be adsorbed on the spin column without the remaining structural analogs (2-nitrophenol, 4-nitrophenol and phenol). After eluting with acetonitrile/acetic acid (9/1, v/v), 2,4-dinitrophenol in serum samples could be determined by using the fluorescence spectrometer, based on the fluorescence enhancement of fluorescein by the template molecule. Under the optimal conditions, the spiked recovery ranged from 95.8% to 103.4% and the detection limit was 1 nmol/L. The results confirmed the reliability and practicality of the protocol and revealed a good perspective of this method for biological sample analysis.
A rapid, sensitive, reproducible and inexpensive method of high-performance liquid chromatography with fluorescence detection after anion-exchange solid-phase extraction clean-up step for the analysis of ochratoxin A (OTA) in Chinese wine was developed. The average recovery rate and the average RSD of recovery were 97.47% and about 4%.The relative standard deviations of both the inter-day and intra-day precision were 6.7% and 12.6%, respectively. The limits of detection and quantitation were determined to be 0.01 μg/L and 0.03 μg/L. A total of 223 samples from the major wine-producing areas of China were analyzed for OTA. OTA was detected at levels of 0.01 to 0.98 μg/L. The mean was 0.15 μg/L. Then, participants as representative inhabitants were invited to answer the designed questionnaire about the quantity and frequency of wine. All data were simulated by the point evaluation for the risk assessment of OTA contamination from wine. Those results indicated that daily intake (DI) of OTA for the average adult consumer varies between 0.86 to 1.08 ng/kg b.w. per week, which was lower than all the reference standards. However, DI value (4.38 to 5.54 ng/kg b.w. per week) in the high percentile (97.5th) was slightly above 5% PTWI (100 ngkg-1w-1) of the JECFA. In conclusion, OTA exposure from Chinese wine has no risk of harm. This research will provide the scientific basis for determining the maximum limit of OTA content in Chinese wine.
Background: By synthesizing results from primary studies, systematic review can provide empirical information of concerned problems. This study aimed to review the available surveillance data from studies reporting the contamination surveillance of food lead in China. Methods: Relevant studies were identified by systematically searching Chinese Biological Medicine Database and China National Knowledge Infrastructure using the key term of "lead" for surveillance data published in Chinese between 2006 and 2012. To avoid potential selection bias, all articles were evaluated by two independent reviewers, and the disagreements were resolved by discussion or the third author was asked to arbitrate. Results: Among 269 identified publications on surveillance data of lead in food, 43 articles met the defined inclusion criteria. The food samples were divided into 11 groups (cereal grains and pulses, fish, eggs, vegetables, meat, edible fungi, milk and dairy products, fruits, offal, tea and preserved egg). Surveillance data of publications were reviewed to calculate the weighted mean and rate exceeding maximum levels. Our results indicated that the highest lead concentration was 1.937 mg/kg in tea. The total percentage of samples exceeding the maximum levels was 5.57%. Dietary exposure to lead was assessed by combining the weighted mean concentration of surveillance data with national consumption data in 2002. In this review, dietary intake of lead was 1.232 µg/kg b.w./day. Conclusion: Further control measures should be taken to reduce exposure to lead, from both dietary and non-dietary sources.
This paper introduces the topic of Food Fraud with translations to Russian, Korean, and Chinese. The concepts provide a system-wide focus leading to prevention. The goal is not to detect Food Fraud but to adjust entire food supply chains to reduce fraud opportunities. Food Fraud is a recently defined area of Food Protection between Food Safety (such as Salmonella or pesticide residue), and Food Defense (malicious intent to harm such as terrorism). Food Fraud is intentional with no intent to harm but only for economic gain. As with improving Food Safety and Food Defense, preventing Food Fraud is good for society and the economy. Society benefits through fewer public health threats from unauthorized acts. Society also benefits from increased consumer satisfaction and harmony. Food Security is increased through the production of more, higher-value products for consumers, commerce, and exporting. Food Fraud can reduce economic output because sickened citizens cannot work and it also reduces consumer confidence leading to less commerce. Copyright © 2014 Elsevier Ltd. All rights reserved.
This paper presents a new analytical method for the determination of rhodamine B (RB) residue in chili powder and chili oil based on a novel reversed-dispersive solid phase extraction (r-dSPE) and ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS). Chili powder and chili oil samples were first extracted with acetonitrile/water (1:1, v/v) and acetonitrile, respectively. Then, RB from the extract was adsorbed to the polymer cation exchange (PCX) sorbent with the characteristics of ion exchange and reversed-phase retention. Subsequently, the analyte in PCX sorbent was eluted with ammonium hydroxide/methanol (1:99, v/v) through a simple unit device equipped with 1mL syringe and 0.22μm nylon syringe filter. All of the samples were analyzed by UHPLC-HRMS/MS on a Waters Acquity BEH C18 column with 0.1% formic acid and 4mM ammonium formate in water/acetonitrile as the mobile phase with gradient elution. The matrix effect, recovery, and repeatability, within laboratory reproducibility, and the LODs and LOQs of the r-dSPE cleanup method were investigated. The method showed a good linearity (R(2)>0.999) in the ranges of 0.01-1μg/L and 1-100μg/L for the analyte. The LODs of RB for chili powder and chili oil samples were 0.5μg/kg. The average recoveries of RB from the samples spiked at four different concentrations (2, 20, 500 and 5000μg/kg) were in a range from 76.7 to 104.9%. Results showed that the proposed method was simple, fast, economical and effective for the determination of RB in chili powder and chili oil. Considering the excellent sorptive performance of PCX for RB, further work should be done to evaluate the usefulness of the PCX in r-dSPE for the clean-up and analyses of other trace-level alkaline contaminants. Copyright © 2014. Published by Elsevier B.V.
To circumvent the strictly regulated administration of antibiotics in milk, illegal addition of β-lactamase to lower the antibiotic levels in milk has been reported recently in China. Herein, we describe a fast, sensitive, and robust HPLC-UV method for the determination of β-lactamase activity in milk, based on an indirect quantification strategy. The test milk sample was mixed with a known amount of penicillin G, a specific substrate of β-lactamase. After incubation, an aliquot of the mixture was injected into the HPLC-UV system to quantify the remaining penicillin G in less than 10 min. Comparative analysis of the amount of penicillin G before and after incubation was used to indirectly deduce the activity of β-lactamase in the test sample. This method was successfully applied to milk products with different fat percentages, resulting in a detection limit of 0.6 U/mL. Good recoveries, ranging from 94 to 105%, were obtained from blank milk samples spiked with β-lactamase at levels of 2 to 50 U/mL, with relative standard deviations <6%. A good correlation was demonstrated between the HPLC method and the conventional culture-based assay. Using this method, the activity changes in β-lactamase during milk pasteurization, sterilization, and storage were investigated. The advantages of low-cost, accurate quantification and easily accessible instrumentation make the proposed method an ideal alternative for high-throughput routine analysis in the dairy industry. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites.
A novel dispersive micro solid phase extraction (DMSPE) method based on a polymer cation exchange material (PCX) was applied to the simultaneous determination of the 30 triazine herbicides in drinking water with ultra high performance liquid chromatography - high resolution mass spectrometric detection. Drinking water samples were acidified with formic acid, then triazines were adsorbed by the PCX sorbent. Subsequently, the analytes were eluted with ammonium hydroxide/ acetonitrile. The chromatographic separation was performed on an HSS T3 column using water (4 mM ammonium formate and 0.1% formic acid) and acetonitrile (0.1% formic acid) as the mobile phase. The method achieved the LODs of 0.2-30.0 ng/L for the 30 triazines, with recoveries in the range of 70.5-112.1%, and the precision of the method was better than 12.7%. These results indicated that the proposed method had the advantages of convenience and high efficiency when applied to analyzing the 30 triazines in drinking water.
Since the year 1990, the Chinese total diet study (TDS) has become an important tool for monitoring dietary exposures to chemicals and their associated risks to public health. Over the course of five such studies in China, emerging chemical contaminants of public health concern have been recognized and added to the list of TDS analytes. The procedures and results for dioxin and dioxin-like compounds, chloropropanols, and acrylamide are described. Using established TDS methods, useful information on the exposure of the Chinese populations has been obtained that will contribute to informed risk management measures. © 2013 Springer Science+Business Media New York. All rights are reserved.
Note: The conclusions and recommendations are for consideration by Codex members, international observer organizations and the Committee. The proposed MLs are for comments at Step 3 by Codex members and international observer organizations and for consideration by the Committee. Codex members and observers are kindly invited to consider supporting information in Appendices I, II and III when submitting comments on the recommendations in particular the proposed MLs in paragraph 6.