[Determination of tetrodotoxin in urine by liquid chromatography-tandem mass spectrometry with internal standard calibration].

OBJECTIVE: An analytical method was developed for tetrodotoxin(TTX) in urine by liquid chromatography-tandem mass spectrometry(LC-MS/MS) with internal standard calibration. METHODS: TTX in the sample was extracted with the mixture of acetic acid/methanol/acetonitrile(0.005 mL/0.8 mL/1.8 mL), cleaned by solid phase extraction(SPE) with cation exchange cartridge, eluted with 50% acetonitrile/water containing 0.3% hydrochloric acid, and neutralized with ammonia. The extract was separated by a Waters XBridge~(TM) BEH Amide column(150 mm×3.0mm, 1.7 µm) and measured by MS/MS. By optimizing sample extraction and SPE cleanup conditions, the problems of low recovery and strong suppression effects of MS signal for TTX in urine were resolved when cleaned with cation exchange cartridge. RESULTS: Quantitatively calibrated by the internal standard of Kasugamycin, good linear relationship was found for TTX in urine at the range of 0.2-200 µg/L with the correlation coefficient(r~2) of 0.997. The limits of detection and quantitation for TTX in sample matrix were 0.1 and 0.2µg/L, respectively. The average recoveries at three spiking levels(0.2, 10.0 and 200 µg/L) were 89.3%-95.3% with relative standard deviation(n=6) less than 5.1%. The concentrations of TTX in urine from 11 poisoning patients were 0.4-138 µg/L. The detection rate was 100% in urine collected within 3 days after poisoning. CONCLUSION: The established method was simple, accurate and sensitive. It can provide reliable technical support for the rapid treatment of TTX poisoning events and the study of toxin metabolism in vivo.

Anatomical Analysis of the Cervical Sympathetic Ganglion and Spinal Ganglion and its Physiological Significance in the Pathogenesis of Cervical Vertigo.

Objective: Investigating the anatomical connections between cervical sympathetic ganglia and spinal ganglia in rabbits and assessing the role of Neuropeptide Y in the pathogenesis of cervical vertigo. Method: Part 1: 32 adult healthy male New Zealand white rabbits (whose skin is very sensitive, so rabbits are generally used for stimulation experiments) were randomly divided into the upper cervical sympathetic ganglia (SCSG) stimulation group and the lower cervical sympathetic ganglia (ICSG) stimulation group, with 16 rabbits in each group. The two groups were divided into an experimental group and a control group, with 8 rabbits in each group. The cervical ganglia of each group of white rabbits were injected with 4% FluoroGold solution and observed under a section microscope. Part 2: Sixty New Zealand white rabbits were randomly divided into a blank control (n = 12), SCSG stimulation group (n = 12), SCSG sham surgery control (n = 12), ICSG stimulation group (n = 12), and ICSG sham surgery control group (n = 12). The SCSG group and ICSG group were subjected to electrical stimulation (i.e. 30.0Hz, 10.0V, 5-minute pulse width of 0.5 ms square wave pulse), and specimens were made. The expression of NPY was detected using immunohistochemical methods. Result: Neuropeptide Y was weakly expressed in all cervical ganglia (C1-C8). Compared with the sham surgery group, the superior cervical sympathetic ganglion stimulation group showed an increase in Neuropeptide Y positive cells in C2, C3, C4, and C5, with C2 and C3 showing the most significant increase. The number of C6, C7, and C8 Neuropeptide Y positive cells in the 3 C、3D and 4B, lower cervical sympathetic ganglion stimulated groups was higher than in the sham sham-operated group, and C6 and C7 significantly increased. Neuropeptide Y is like immunoreactive neurons in the cervical spinal ganglia, and the immunoreactive products are small brown particles distributed in the cytoplasm after electrical stimulation of the cervical sympathetic ganglia. The Neuropeptide Y content in the corresponding segment of the cervical spinal ganglia is significantly increased compared to the control group (P < .05). Conclusion: In New Zealand white rabbits, nerve fibers are interconnected between the cervical sympathetic ganglion and the cervical spinal ganglion, and this neural fiber connection has a certain segmental nature, providing experimental basis for the existence of the cervical spinal cord external nerve reflex arc and elucidating the pathogenesis of cervical vertigo in terms of neural anatomy. By using neuroelectrophysiological methods, it has been confirmed that electrical stimulation in the cervical spinal ganglia can reach the corresponding cervical sympathetic ganglia on the same side through a certain conduction pathway, providing experimental basis in neuroelectrophysiology for the existence of the cervical extraspinal nerve reflex arc and elucidating the pathogenesis of cervical vertigo. NPY may be involved in the pathogenesis of cervical vertigo, providing a theoretical basis for the clinical diagnosis of cervical vertigo.

[Simultaneous determination of 16 polycyclic aromatic hydrocarbons in source water and tap water by performance liquid chromatography with ultraviolet detector tandem fluorescence detector combined with solid phase extraction].

OBJECTIVE: To establish a rapid method for simultaneous determination of 16 polycyclic aromatic hydrocarbons(PAHs) in source water and tap water by performance liquid chromatography(HPLC) with ultraviolet detector(UV) tandem fluorescence detector(FLR). METHODS: Source water was filtered by GF/C glass fiber filters and tap water were added ascorbic acid of 60 mg per liter to remove the residual chlorine when sampling. 500 mL water sample were sampled and adjusted pH 2 with phosphoric acid, then 10 mL methanol were added. Then samples were concentrated by styrene stilbene polymer solid phase extraction column, after loading samples, 50 percent methanol aqueous solution adjust pH 2 were used for washing bottle and the washed solution were continuum loaded. Then 80 percent methanol aqueous solution was used for removing impurity interference and elution with dichloromethane. The eluent was nitrogen blow to near dry after adding 100 µL 10 percent tween-20 methanol solutions(m/V). Acetonitrile was used for reconstitution, and then separated by PAH chromatography column using acetonitrile and pure water at gradient elution, and detected by UV tandem FLR detector. RESULTS: The linear ranges of 16 PAHs were 0. 5 to 500 ng/mL and the correlation coefficients were greater than 0. 999. The method detection limit and limits of quantification were 0. 3 to 5. 0 ng/L and 1. 2 to 20. 0 ng/L, respectively. The recoveries were in the range of 67. 2%-114. 1% with the relative standard deviations ranging from 1. 5%-14. 0%(n=6). Then the established method was used for the determination of 17 water samples, 8 kinds, 6 kinds and 7 kinds of PAHs were detected in source water, tap water and pipe net tap water, respectively. CONCLUSION: The method is rapid, sensitive and selective, and has been successfully applied for determination of 16 PAHs in source water and tap water.

Simultaneous detection of multiple hydroxylated polychlorinated biphenyls from biological samples using ultra-high-performance liquid chromatography with isotope dilution tandem mass spectrometry.

We established a method for the separation and detection of nine hydroxylated polychlorinated biphenyls in whole blood and urine samples using ultra high performance liquid chromatography coupled with electrospray negative ionization tandem mass spectrometry. Clean-up procedures involved a filtration step, and optimization involved a pretreatment step consisting of a simple liquid-liquid extraction using hydrated silica-gel chromatography (5%). Nine hydroxylated polychlorinated biphenyls were separated on an ultra high performance liquid chromatography HSS T3 column using a gradient elution program of 2 mmol ammonium formate aqueous solution (A) and methanol (B). Recovery ranged from 84.0 to 105.4% for the nine different hydroxylated polychlorinated biphenyls in urine with three spiked levels of 0.1, 1, and 2 ng and from 73.5 to 98.6% for the blood with spiked levels of 0.2, 1, and 2 ng. The relative standard deviations were <8.7% (n = 6), and the limits of detection in urine and whole blood for the nine hydroxylated polychlorinated biphenyls were in the range of 1.5-4 and 20-100 pg/g, respectively. This analytical method may enable the simultaneous detection of various hydroxylated polychlorinated biphenyls from complex tissue matrices.

The correlation between SNPs within the gene of adrenergic receptor and neuropeptide Y and risk of cervical vertigo.

BACKGROUND: The current investigation was aimed to explore the potential associations of SNPs within ADRB2, ADRB1, NPY, and ADRA1A with risk and prognosis of cervical vertigo. METHODS: Altogether 216 patients with cervical vertigo and 204 healthy controls were gathered, and their DNAs were extracted utilizing the whole-blood DNA extraction kit. Besides, the PCR reactions were conducted using the TaqManR single nucleotide polymorphism (SNP) genotyping assays, and the SNPs were detected on the 7900HT real-time fluorogenic quantitative polymerase chain reaction (PCR) instrument. Finally, the severity of cervical vertigo was classified according to the JOA scoring, and the recovery rate (RR) of cervical vertigo was calculated in light of the formula as: [Formula: see text] RESULTS: The SNPs within ADRA1A [rs1048101 (T>C) and rs3802241 (C>T)], NPY [rs16476 (A>C), rs16148 (T>C), and rs5574 (C>T)], ADRB1 [rs28365031 (A>G)] and ADRB2 [rs2053044 (A>G)] were all significantly associated with regulated risk of cervical vertigo (all P < .05). Haplotypes of ADRA1A [CT and TC] and NPY [CCT and ATT] were also suggested as the susceptible factors of cervical vertigo in comparison with other haplotypes. Furthermore, the SNPs within ADRA1A [rs1048101 (T>C)], NPY [rs16476 (A>C), rs16148 (T>C)], as well as ADRB1 [rs28365031 (A>G)] all appeared to predict the prognosis of cervical vertigo in a relatively accurate way (all P < .05). Ultimately, the haplotypes of ADRA1A (CC) and NPY (CCT) tended to decrease the RR. CONCLUSIONS: The SNPs within ADRB2, ADRB1, NPY, and ADRA1A might act as the diagnostic biomarkers and treatment targets for cervical vertigo.

Distribution and Probabilistic Risk Assessment of Antibiotics, Illegal Drugs, and Toxic Elements in Gastropods from Southeast China.

We investigated fourteen antibiotics, three illegal drugs, and two toxic elements in commercially available gastropods from southeast China. The data revealed high detection frequencies (DFs) for florfenicol (61.32%), florfenicol amine (47.33%), and thiamphenicol (39.88%), with maximum concentrations of 1110, 2222, and 136 µg/kg wet weight (ww), respectively. The DFs of illegal drugs were 3.54% for leucomalachite green and 0.3% for chloramphenicol. The average levels of Cd and As were 1.17 and 6.12 mg/kg ww, respectively. All chemicals presented diverse DFs in different sampling months. The highest DFs of florfenicol, florfenicol amine, and thiamphenicol were in July. The health risk assessment showed that targeted hazard quotients (THQs) of antibiotics, Cd, and As for children, teens, and adults were all less than one. Notably, the toxic elements (Cd and As) were identified as the primary health risk in gastropods, contributing to over 90% of the total THQs.

Antibiotic residues in commercial freshwater fish from southeast China: distribution and human health risk assessment.

We investigated 14 antibiotic residues in 8 marketed freshwater fish species from southeast China and estimated the associated health risks to local consumers. The antibiotic residues were determined by UPLC-MS/MS. Our findings revealed widespread distribution of quinolones (QNs), tetracyclines (TCs), and chloramphenicols (CAPs) in the freshwater fish. Notably, the average concentrations of enrofloxacin and ciprofloxacin reached levels as high as 62.5 µg/kg wet weight (ww) and 11.7 µg/kg ww, respectively, and detection frequencies were 68.7% for enrofloxacin and 31.6% for ciprofloxacin. Additionally, we detected chloramphenicol, a prohibited antibiotic, in samples with a detection frequency of 0.76%. Among the fish species, the mean concentration of total antibiotic residues was highest in bluntnose black bream (263.3 µg/kg), followed by English perch (52.4 µg/kg), crucian carp (46.3 µg/kg), black carp (28.6 µg/kg), yellowcheek carp (21.0 µg/kg), grass carp (15.3 µg/kg), bighead carp (3.78 µg/kg), and mandarin fish (3.69 µg/kg). We estimated the daily intake values of these antibiotic residues which were lower than the acceptable daily intake values and hazard indexes were much less than 1. It indicates that there is very low direct health risk to consumers. Despite that, investigation on the chronic impact, such as antibiotic-resistant bacteria, gut microbiota disruption, and allergic reactions, is urgently needed.

Effect of Otago exercise on fear of falling in older adults: a systematic review and meta-analysis.

BACKGROUND: Approximately 40-70% of older adults who have experienced falls develop fear of falling (FOF), with the incidence rate in nursing home residents reaching as high as 79.4%. An increasing number of studies have focused on the effect of the Otago Exercise Programme (OEP) on reducing FOF among older adults, yet comprehensive analysis is lacking due to regional and demographic variations. Therefore, this study integrates the relevant literature to provide evidence supporting interventions aimed at alleviating FOF among older adults. OBJECTIVE: To evaluate the impact of OEP on FOF in older adults through meta-analysis. METHODS: We searched ten databases using computer systems, covering all records up to May 1, 2024. Two researchers independently conducted the literature screening, bias risk assessment, and data extraction. We performed data analysis using RevMan 5.3 and Stata 15.0 software, assessed result stability through sensitivity analysis, and examined publication bias with funnel plots and Egger's test. RESULTS: Sixteen RCTs were included. Meta-analysis revealed that the OEP significantly reduced FOF among older adults [SMD = 0.96, 95%CI (0.68, 1.23), P < 0.00001]. Subgroup analysis revealed that interventions lasting more than 16 weeks [SMD = 1.12, 95%CI (0.75, 1.49), P < 0.00001], with a frequency of more than twice a week [SMD = 0.99, 95%CI (0.64, 1.35), P < 0.00001], and for older adults in community and nursing institutions [SMD = 1.03, 95%CI (0.50, 1.57), P = 0.0002] were more effective. A comparison of the 16-week and 24-week interventions revealed that the latter had better outcomes [SMD = 0.87, 95%CI (0.66, 1.08), P = 0.0004]. CONCLUSION: Current evidence indicates that OEP effectively reduces FOF among older adults. It is recommended that interventions last for more than 24 weeks, occur more than twice a week, and suitable for application among older adults in community settings or elder care institutions.

Heavy metals accumulation in bivalve mollusks collected from coastal areas of southeast China.

The distribution of six heavy metal and metalloids (As, Cd, Cr, Hg, Ni and Pb) was analyzed in 597 bivalve mollusks (8 species) collected from coastal areas of southeast China. Target hazard quotient, total hazard index, and target cancer risk were calculated to evaluate potential human health risks from bivalve consumption. The mean concentrations of As, Cd, Cr, Hg, Ni and Pb were 1.83, 0.581, 0.111, 0.0117, 0.268 and 0.137 mg kg-1 wet weight in bivalves. The average estimated daily intakes for As, Cd, Cr, Hg, Ni and Pb were 1.156, 0.367, 0.07, 0.007, 0.167 and 0.087 µg kg-1 body weight/day. Health risk assessment showed that there was no non-carcinogenic health risk to general residents to these metals from consumption of bivalves. Cd intake through mollusks posed a potential cancer risk. Accordingly, regular monitoring for heavy metals, especially Cd is recommended with respect to potential contaminant on marine ecosystems.

Distribution of Cadmium in Fresh Vegetables Marketed in Southeast China and Its Dietary Exposure Assessment.

This study investigated concentrations of cadmium (Cd) in 2465 vegetable samples (52 species) from 2018 to 2022 and estimated the associated health risk for local consumers. The average concentration of Cd was 0.035 mg kg-1, and the percentage of samples exceeding the Chinese maximum allowed concentration was 3.89% (96/2465). The top five species with highest Cd levels were Lilium brownii F (0.182 mg kg-1), Allium chinense G (0.117 mg kg-1), Allium macrostemon Bunge (0.105 mg kg-1), Colocasia esculenta (0.064 mg kg-1), and Amaranthus tricolor L (0.054 mg kg-1). Bulb vegetables had a higher relative accumulation of Cd compared to other vegetables. The levels of Cd in vegetables varied significantly across sampling areas and years. The mean estimated daily intake (EDI) of cadmium through consumption of vegetables was 0.519 µg kg-1 bw per day for adults and 0.217 µg kg-1 bw per day for children. The target hazard quotients (THQs) were all less than the threshold of 1 for both adults and children. This indicates that there is low health risk for Cd through vegetable consumption. However, routine monitoring of Cd levels in food is still crucial to ensure food safety and protect public health.

Toxic Elements in Beans from Zhejiang, Southeast China: Distribution and Probabilistic Health Risk Assessment.

This study described the distribution of As, Cd, Cr, Hg, and Pb in 692 bean samples from Zhejiang province, southeast China, and estimated the health risk using Monte Carlo simulation. The average levels of As, Cd, Cr, Hg, and Pb were 0.0349, 0.0379, 0.246, 0.0019, and 0.0246 mg kg-1. Correlation analyses showed very strong positive correlations for Cd-Pb in kidney beans and mung beans, Cd-As in black beans, and Pb-As in red beans. The target hazard quotients (THQs) were adopted for non-carcinogenic risk assessment, and THQs at the 50th percentile were all less than 1, indicating that there are no deleterious effects from rice exposure to these elements. When evaluating THQ for multiple elements, the certainty with a hazard index (HI) greater than 1 for children was 12.64%, for teens 11.54%, and for adults 1.01%. The sensitivity analysis reveals that the concentration of Cd in beans and ED (exposure duration) are the main principal factors that contributed to the total risk. The mean carcinogenic risks for children, teens, and adults were all less than 1 × 10-4, indicating no potential carcinogenic risk. Despite that, the routine monitoring of these elements, especially for Cd should be continued.

Quantification of 37 glucocorticoids in chicken muscle by UHPLC-Q-Orbitrap-MS with parallel reaction monitoring.

The quantification capability of high-resolution mass spectrometry (HRMS) has received increasing interest from analysts. In this study, we present a method for analyzing 37 glucocorticoids in chicken muscle using UHPLC-Q-Orbitrap MS with parallel reaction monitoring (PRM). The analytes were extracted using acetonitrile (ACN) containing 0.1% formic acid and subjected to commercial PRiME HLB solid-phase extraction (SPE) cartridge clean-up. Under optimized conditions, the analytes were separated on an analytical column and subsequently detected using a high-resolution hybrid quadrupole/Orbitrap mass spectrometer coupled with PRM scan mode. The Q-Orbitrap with PRM exhibited remarkable sensitivity, with limits of quantification (LOQs) ranging from 0.08 µg kg-1 to 7.59 µg kg-1. To validate the method, we conducted intra- and inter-day tests using a blank matrix sample at different spiking levels. The achieved results demonstrated satisfactory recovery values (74.1-97.5%) and precise results (RSDs < 15%) for all the studied analytes. In application, we found dexamethasone with 6.5 µg kg-1 and fluorometholone with 3.9 µg kg-1 in two chicken samples. These findings suggest that the UHPLC-Q-Orbitrap system, in conjunction with the SPE sample preparation method, has great potential as a routine quantification approach for multiple glucocorticoid residues in chicken samples.

Analytical Method Optimization of Tetrodotoxin and Its Contamination in Gastropods.

Tetrodotoxin (TTX) is an extremely potent marine biotoxin. An analytical method was developed for both trace contamination and extremely high levels of TTX in gastropods by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with clean-up of cation exchange solid phase extraction (SPE) in this study. The limit of detection (LOD) in the sample matrix was 0.5 µg/kg. With the calibration of a screened internal standard (validamycin, IS), the linear range was 0.1-100 ng/mL (1.5-1500 µg/kg in sample matrix) with a correlation coefficient of r2 > 0.999. The average recoveries at three spiking levels (1.5 µg/kg, 44 µg/kg, and 1500 µg/kg) were 82.6-94.4% with relative standard deviations (RSDs) less than 8.4%. TTX levels in seven gastropods (741 samples) were studied. The contamination and analogues in Neverita didyma (N. didyma, 565 samples collected in Zhejiang province, China, from 2016 to 2022) were first reported. The detection rate of TTX in N. didyma was 34.2%. The average concentration was 23.1 µg/kg, and the maximum value was 2327 µg/kg. The time distribution study indicated that high contaminations of TTX occurred from May to August for N. didyma.

Determination of steroid hormone residues in farmed fish using high-resolution orbital ion trap mass spectrometry.

A method for the determination of 15 steroid hormones in farmed fish by liquid chromatography-orbital ion trap mass spectrometry has been developed and validated. The method involved sample preparation with acetonitrile extraction and clean-up, and separation in the LC using a C18 column. The orbital ion trap MS was operated at a resolution of 35 000 FWHM in selected ion monitoring mode. An ion source with heated electrospray ionization was used in positive ionization mode. The samples were prepared by solid-phase extraction. The limit of quantification of steroid hormones in fish samples was 2 µg kg-1. Good linearity was observed since correlation coefficients were more than 0.99 for all compounds. Recoveries of spiked fish samples (2 µg kg-1 and 20 µg kg-1) ranged from 80.8% to 112.6% with relative deviations less than 15%. The method was successfully applied to detect steroid hormones in real farmed fish samples at the µg kg-1 level.

Use of different endpoints to determine the bioavailability of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in Sprague-Dawley rats.

Liver, fat (adipose tissue), blood, and feces are common endpoints used to determine the bioavailability of persistent organic pollutants (POPs). However, it is not known whether the bioavailability of each endpoints is comparable or whether there is a comprehensive endpoint that can be used for all congeners for the measurement of bioavailability. In this study, we observed the accumulation and distribution of 10 polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and 18 polychlorinated biphenyls (PCBs) in different organs of Sprague-Dawley (SD) rats and calculated the bioavailability based on feces, liver, and fat endpoints. Our results indicated that PCB 126, PCB 169, and 50% of PCDD/F congeners were mainly accumulated in the liver, with a bioavailability ranging from 28.9 to 50.6%. On the other hand, higher chlorinated (> 5 Cl) PCB congeners were mainly accumulated in adipose tissues, with a bioavailability ranging from 20.1 to 82.2%, while lower chlorinated (< 5 Cl) pollutants, such as 2,3,7,8-TeCDF, 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDF, and PCB 28, 52, 77, 81, were likely metabolized over 36% in rats during the 8-week experimental period. If we considered metabolization (degradation) as a type of bioavailable process, then the fecal endpoint was a feasible option. However, if we considered the selective accumulation behavior of some congeners in different organs/tissues, then there was no single comprehensive endpoint suitable for all congeners. Lastly, female rats showed significantly higher PCDD bioavailability than male rats at low dose level (0.2 ng/100 g b.w./d); however, the difference in PCB bioavailability between female and male rats was not significant.

Multi-residue analysis of pesticides in tea by online SEC-GC/MS.

A multi-residue method for the analysis of pesticides in tea was developed by online size exclusion chromatography (SEC)-GC/MS with full scan mode. The sample was fortified with chlorpyrifos-d(10) isotope internal standard and extracted by acetonitrile. After purification by primary secondary amine sorbent and solvent exchange by SEC mobile phase, the sample was detected by online SEC-GC/MS. The purification result of the online system was evaluated by comparing the correlation between Chinese cabbage and tea matrix. The factors for method optimization included sample preparation, matrix effects and the instrument parameters of each online component. Scatter plot was introduced in this study to directly illustrate the results of the condition optimization and matrix effects in the online system. For most of the pesticides, the average recoveries ranged from 70 to 130% and the RSD were below 15%. The feasibility of the application of full scan mode in multi-residue determination of trace amounts of pesticides (LODs below 0.01 mg/kg) in a complex matrix was discussed.

Correlations of PCBs, DIOXIN, and PBDE with TSH in children's blood in areas of computer E-waste recycling.

OBJECTIVE: To study correlations of polychlorinated biphenyls (PCBs), DIOXIN, and polybrominated diphenyl ethers (PBDE) with thyroid stimulating hormone(TSH) in children, and assess the impact on children's health. METHODS: Three hundred and sixty nine children aged from 6 to 8, including 195 from Luqiao, the computer E-waste recycling area, and 174 from Longyou, the control area, were selected for this investigation to elucidate the correlation of PCBs, DIOXIN, and PBDE with TSH in children's blood samples. The children had a physical examination and their blood levels of PCBs, DIOXIN, PBDE, and TSH were detected after sample collection. RESULTS: In the E-waste recycling area, the contents of PCBs, PBDE, DIOXIN, and TSH in the blood samples of children were 484.00 ± 84.86 ng·g(-1) lipid weight, 664.28 ± 262.38 ng·g(-1) lipid weight, 26.00 ± 19.58 ng·g(-1) lipid weight and 1.88 ± 0.42 µIU/mL (serum) respectively, while in the control area, the PCBs, PBDE, DIOXIN, and TSH contents were 255.38 ± 95 ng·g(-1) lipid weight, 375.81 ± 262.43 ng·g(-1) lipid weight, 39.64 ± 31.86 ng·g(-1) lipid weight, and 3.31±1.04 µIU/mL respectively. CONCLUSION: The health status of children in the control area are better than that in the contaminated area. Among children who are exposed to persistent organic pollutants, the pollutant content increases significantly in their serum, and the distribution of TSH levels in their bodies are also affected.

Health risk assessment of heavy metals in marine fish to the population in Zhejiang, China.

Environmental pollution with toxic metals can lead to the possible contamination of the marine fish. We investigated the levels of As, Cd, Cr, Hg and Pb in 652 marine fish samples (15 species) collected from coastal areas of Zhejiang, China and estimated their health risk. Mean concentrations of As, Cd, Cr, Hg and Pb were 0.783, 0.009, 0.114, 0.031, 0.043 mg/kg wet weight. The average estimated daily intakes (EDIs) for As, Cd, Cr, Hg and Pb were 1.214, 0.014, 0.177, 0.048 and 0.067 µg/kg bw/day. The risk assessment at mean exposure level showed that there was no health risk associated with these elements through consumption of marine fish. However, potential health risk may exist for high exposure consumers considering the possible contamination of As and Hg. Given that the different levels of certain elements in marine fish in China, this study provides a scientific basis for food safety assessment and suggestions for risk management.

Effects of curcumin on the bioavailability of dioxin-like pollutants in rats.

The effects of curcumin on the bioavailability of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) were investigated in Sprague-Dawley rats. Tetra- and penta-chlorinated PCDFs had the lowest bioavailability and hexa-chlorinated PCDD/Fs had the highest, while there was no obvious change in that of DL-PCBs. Curcumin markedly reduced the toxic equivalent (TEQ) of PCDD/Fs in rats, illustrating the potential to competitively inhibit absorption of PCDD/Fs by the epithelial cells of the small intestine due to the similar chemical structure (diphenyl) between curcumin and PCDD/Fs. Moreover, curcumin lowered the TEQ of DL-PCBs in the liver of male rats, but not female rats. The significant decrease in the bioavailability of PCDD/Fs and DL-PCBs demonstrates the potential detoxification mechanisms of curcumin.

Analytical method development for α-amanitin and ß-amanitin in plasma at ultra-trace level by online solid phase extraction-high performance liquid chromatography-triple quadrupole mass spectrometry and its application in poisoning events.

α-Amanitin and ß-amanitin are the main fatal mushroom toxins. The toxins metabolize rapidly in blood and are reported hard to be detected 24 h after poisoning. The main challenge is that of developing a highly sensitive method at sub-pg mL-1 level in blood to diagnose intoxication cause and to study the poisoning mechanism and blood toxicity kinetics. An analytical method for α-amanitin and ß-amanitin at ultra-trace level was developed in this study by online solid phase extraction-high performance liquid chromatography-triple quadrupole mass spectrometry (online SPE-LC-MS/MS). Simple protein precipitation and liquid-liquid extraction were introduced to resolve the sample preparation problem of the online SPE-LC-MS/MS system with large-volume injection. A quick valve-switching technique with a quantitative loop as interface was used in the online system. This design can ensure the independence of flow path and pressure between the SPE and LC-MS/MS modules and can obtain the precise cleanup of the toxins. The limits of detection for α-amanitin and ß-amanitin in plasma were both 0.02 ng mL-1. The linear ranges were 0.05-20 ng mL-1 with a correlation coefficient r >0.99. The average recoveries at three spiking levels were 82.9 %-92.2 % with the relative standard deviations (RSD) of 5.4 %-8.0 % for α-amanitin and 84.5 %-93.9 % with RSDs of 4.5 %-7.8 % for ß-amanitin. The composition and concentration of the toxins in plasma from 18 patients in 5 mushroom poisoning events caused by aminitins were studied. The developed method has high positive confirmation ability and can identify toxins in plasma 40 h after poisoning.