Health risks posed to infants in rural China by exposure to short- and medium-chain chlorinated paraffins in breast milk.

Chlorinated paraffins (CPs) are complex mixtures of synthetic chemicals found widely in environmental matrices. Short-chain CPs (SCCPs) are candidate persistent organic pollutants under the Stockholm Convention. There should be great concern about human exposure to SCCPs. Data on CP concentrations in human breast milk is scarce. This is the first study in which background SCCP and medium-chain CP (MCCP) body burdens in the general rural population of China have been estimated and health risks posed to nursing infants by CPs in breast milk assessed. The concentrations of 48 SCCP and MCCP formula congeners were determined in 24 pooled human milk samples produced from 1412 individual samples from eight provinces in 2007 and 16 provinces in 2011. The samples were analyzed by comprehensive two-dimensional gas chromatography electron capture negative ionization high-resolution time-of-flight mass spectrometry. The median SCCP and MCCP concentrations were 303 and 35.7ngg-1 lipid weight, respectively, for the 2007 samples and 360 and 45.4ngg-1 lipid weight, respectively, for the 2011 samples. The C10 and C14 homologs were the dominant CP carbon-chain-length groups, contributing 51% and 82% of the total SCCP and MCCP concentrations, respectively. There are probably multiple CP sources to the general Chinese population and numerous exposure pathways. The median estimated daily SCCP and MCCP intakes for nursing infants were 1310 and 152ngkg-1d-1, respectively, in 2007 and 1520 and 212ngkg-1d-1, respectively, in 2011. SCCPs do not currently pose significant risks to infants in China. However, it is necessary to continuously monitor CP concentrations and health risks because CP concentrations in Chinese human breast milk are increasing.

The Benefit Risk Assessment of Consumption of Marine Species Based on Benefit-Risk Analysis for Foods (BRAFO)-tiered Approach.

OBJECTIVE: To assess the net health effect caused by the consumption of specific marine species based on Benefit-Risk Analysis for Foods (BRAFO)-tiered approach. METHODS: Twenty species were collected from the Zhoushan Archipelago, China. Concentrations of n-3 long-chain polyunsaturated fatty acids, methyl mercury (MeHg), and dioxin-like compounds (DLCs) in the samples were analyzed for benefit risk assessment based on BRAFO-tiered approach. RESULTS: Based on the BRAFO-tiered approach, reference scenario (no intake) and alternative scenario (intake of specific species of 200 g/week) were determined. The exposure to MeHg/DLCs via alternative scenario of all studied species did not exceed provisional tolerable weekly/monthly intake. However, the adult population with high DLCs exposure in China would significantly exceed the upper limit of DLCs via an additional alternative scenario of some species such as Auxis thazard. The results of deterministic computation showed that alternative scenario of all studied species generated clear net beneficial effects on death prevention and child IQ gain. CONCLUSION: The alternative scenario of all studied species could be recommended to population with average DLCs exposure, and the reference scenario of species with relatively high DLCs concentration could be recommended to population exposed to high DLCs.

Levels of PCDDs, PCDFs and dl-PCBs in the blood of childbearing-aged women living in the vicinity of a chemical plant in Tianjin: a primary study.

Several studies have suggested that maternal exposure to Polychlorinated dibenzo-p-dioxins (PCDDs), poly-chlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (PCBs) may affect foetal growth and infant development. The aim of our study was to determine whether the childbearing-aged residents living near a chemical plant have a greater exposure risk. Concentrations of 17 PCDD/Fs congeners and 12 non-ortho and mono-ortho dioxin-like PCBs were measured using HRGC-HRMS in the blood of 30 non-occupational childbearing-aged women living near a chemical plant (Dagu) that had been producing chlorinated pesticides from 1958 to 2004. The factors that influenced the body burden were investigated based on responses to a questionnaire. Levels of PCDD/Fs+PCBs were in the range of 16.43-155.29pg WHO 2005-TEQg(-1) lipid. PCDDs and PCDFs contributed 56.72% and 34.44%, respectively, to the total TEQ value. Total WHO-TEQ was approximately tenfold higher in the participants living in the vicinity of the plant (distance: 1.52±0.148km) than in the groups living farther away (distance: 4.93±1.124km). A negative correlation between total WHO-TEQ and distance to Dagu was observed by multiple linear regression models. The data provide basic information for monitoring dioxin-like chemicals in the district and for the future study of the relationship between POPs and pregnancy outcomes.

Estimating the burden of acute gastrointestinal illness in the community in Gansu Province, northwest China, 2012-2013.

BACKGROUND: Acute gastrointestinal illness (AGI) imposes considerable social and economic burden on low and middle-income countries. This study aimed to estimate the occurrence, distribution, and burden of self-reported AGI in Gansu Province of northwest China, where economic growth rates have lagged far behind those of other regions in China and systematic studies to investigate the burden of AGI are still lacking. METHODS: Twelve-month, retrospective face-to-face surveys were conducted in three sentinel sites between June 2012 and May 2013. Respondents were asked if they had experienced diarrhoea or vomiting in the 28 days prior to the interview. RESULTS: In total, 2094 interviews were completed. The adjusted monthly prevalence was 8.5% with an incidence rate of 1.16 episodes of AGI per person-year. Healthcare was sought by 73.8% of those reporting illness. Of the cases who visited a doctor, 50.5% submitted a stool sample. The use of antibiotics was reported by 65.6% of the cases and 53.3% took antidiarrhoeals. In the multivariable model, age, household income and sentinel site were significant risk factors of being a case of AGI. CONCLUSIONS: The burden of AGI was considerable in Gansu Province of northwest China. Ongoing research to identify the main causes of AGI is needed for more accurate estimate of the burden of AGI in this region.

Exposure assessment to ochratoxin A in Chinese wine.

A rapid, sensitive, reproducible, and inexpensive method of high-performance liquid chromatography with fluorescence detection after an anion-exchange solid-phase extraction cleanup 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 interday and intraday precision were 6.7 and 12.6%, respectively. The limits of detection and quantitation were determined to be 0.01 and 0.03 µg/L, respectively. A total of 223 samples from the major wine-producing areas of China were analyzed for OTA. OTA was detected at levels of 0.01-0.98 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 consumption. 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 and 1.08 ng/kg bw per week, which was lower than all the reference standards. However, the DI value (4.38-5.54 ng/kg bw per week) in the high percentile (97.5) was slightly above 5% PTWI (100 ng kg(-1) week(-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.

Application of gas chromatography-mass spectrometry in analyzing pharmacokinetics and distribution of deltamethrin in miniature pig tissues.

OBJECTIVE: To characterize the pharmacokinetics and distribution profiles of deltamethrin in miniature pig tissues by gas chromatography-mass spectrometry (GC-MS). METHODS: Pharmacokinetics and distribution of deltamethrin in blood and tissues of 30 miniature pigs were studied by GC-MS after oral administration of deltamethrin (5 mg/kg bw). Data were processed by 3P97 software. RESULTS: The serum deltamethrin level was significantly lower in tissues than in blood of miniature pigs. The AUC0-72 h, Cmax, of deltamethrin were 555.330 ± 316.987 ng h/mL and 17.861 ± 11.129 ng/mL, respectively. The Tmax, of deltamethrin was 6.004 ± 3.131 h. CONCLUSION: The metabolism of deltamethrin in miniature pigs is fit for a one-compartment model with a weighting function of 1/C2. Deltamethrin is rapidly hydrolyzed and accumulated in miniature pig tissues.

[The human body burden of polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls in residents' human breast milk from Beijing in 2007].

OBJECTIVE: To investigate contamination levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in human breast milk from Beijing residents, and evaluate the human body burden of PCDD/Fs and dl-PCBs of general population. METHODS: A total of 110 human milk samples were collected from 11 regions in Beijing in 2007. After 11 pooled samples were made, concentrations of PCDD/Fs and dl-PCBs in breast milk pooled samples were measured by a high resolution gas chromatography - high resolution mass spectrometry (HRCG-HRMS) with isotope dilution. RESULTS: For congeners of PCDD/Fs and dl-PCBs in human breast milk from Beijing, the highest content of congeners was octachlorodibenzo-p-dioxin (OCDD), polychlorinated biphenyl (PCB)-118, and PCB-105 with the median of 20.6 pg/g fat, 4.07 ng/g fat and 1.63 ng/g fat, respectively. The concentration median of total dioxins in 11 pooled human milk samples from Beijing was 7.4 pg TEQ/g fat. The highest was 13.5 pg TEQ/g fat from Tongzhou, and the lowest was 4.3 pg TEQ/g fat from Pinggu. CONCLUSION: The contamination level of PCDD/Fs and dl-PCBs in human milk from Beijing is relatively low. However, with the rapid industrialization in China, the human body burden of PCDD/Fs and dl-PCBs will be likely to rise. Thus, further studies should be conducted to continuously monitor the trend of contamination level.

Burden of self-reported acute gastrointestinal illness in China: a population-based survey.

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.

[Polybrominated diphenyl ethers load in human serum of Taiyuan city in 2010].

OBJECTIVE: This study was conducted to characterize polybrominated diphenyl ethers (PBDEs) load in human serum of Taiyuan city in 2010. METHODS: A total of 42 blood samples were collected in Taiyuan city, 2010. Solid-phase extraction (SPE)-gas chromatography-negative chemical ionization-mass spectrometry method was used to measure the concentration of brominated diphenyl ethers (BDE)-17, BDE-28, BDE-47, BDE-66, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183 and BDE-209 and ΣPBDEs was calculated. RESULTS: Of the tested serum samples, ΣPBDEs ranged from 2.09 to 66.74 ng/g of lipid weight (lw), the median and mean was 6.32 ng/g lw and 9.84 ng/g lw, respectively. BDE-209 was the main source of ΣPBDEs and its concentration ranged from no detection to 64.99 ng/g lw, the median was 4.11 ng/g lw, accounting for 67.6% of ΣPBDEs. Second source was BDE-153 and its concentration ranged from 0.29 to 4.92 ng/g lw, the median was 0.62 ng/g lw accounting for 10.1% of ΣPBDEs. CONCLUSION: The overall load of PBDEs in the serum of local residents was low in 2010.

Polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) in marine fish from four areas of China.

The levels of polybrominated diphenyl ethers (PBDEs) and indicator polychlorinated biphenyls (PCBs) were determined in marine fish from four areas of China (South China Sea, Bohai Sea, East China Sea, and Yellow Sea) using GC/NCI-MS and GC/ITMS, respectively. Total concentrations of eight PBDEs (BDE-28, 47, 99, 100, 153, 154, 183 and 209) in all samples ranged from 0.3ngg(-1)ww (wet weight) to 700 ng g(-1)ww, with median and mean values of 85 ng g(-1)ww and 200 ng g(-1)ww, respectively. BDE-209 and BDE-47 were the major congeners in all samples, contributing 54% and 19% to the total concentration, respectively. The sum of seven indicator PCB levels (CB-28, 52, 101, 118, 138, 153, and 180) ranged from 0.3 ng g(-1)ww to 3.1 µg g(-1)ww, with median and mean values of 6.4 ng g(-1)ww and 398 ng g(-1)ww, respectively. High contributions of CB-138 (32%) and CB-153 (25%) were found in all samples. In general, pollutants measured in this study were at high levels when compared with previous studies from other regions in the world. The relative abundance of BDE-209 may suggest that deca-BDE sources existed in studied area. And principal component analysis (PCA) showed that there were other PBDE sources in Yellow Sea. The pattern and PCA showed that PCB pollutions came from similar sources in the studied areas. In addition, concentrations of ∑(7)PBDEs (u/209) were strongly correlated with those of ∑(7)PCBs in all fish (r=0.907, n=44).

Fast analysis of polybrominated diphenyl ethers in eggs using selective pressurized liquid extraction coupled with online GPC-GC/MS.

This article reports the applicability of online gel permeation chromatography (GPC)-GC/MS for the determination of seven predominant polybrominated diphenyl ethers (PBDEs) in eggs to effectively eliminate matrix interference. Selective pressurized liquid extraction using acidic alumina as a fat retainer was used for cleanup of the PBDEs in eggs. It was selected because of its advantages: simpler operation, minimum time spent on sample handing to get fat-free extracts, and low volume of solvent consumption. After concentration, the extract was directly injected for online GC/MS operated in the negative ion chemical ionization mode with a 15 m capillary column. Recoveries of spiked samples were between 75.1 and 102.0%, with RSDs (n=3) ranging from 3.69-11.47% when spiked at levels of 2 and 20 ng/g, dry mass. The LOD varied from 0.25-34 ng/g, dry mass. The proposed method was proven to be rapid, efficient, and reliable for the trace determination of PBDEs in eggs.

[Smoking status or age impact on urinary 8-hydroxy-2'-deoxyguanosine in electrical and electronic equipment waste dismantling workers].

OBJECTIVE: To investigate the smoking or age impact on occupational workers in electrical and electronic equipment waste (e-waste) dismantling procedure, using 8-Hydroxy-2'-deoxyguanosine (8-OHdG) in the urine as a biomarker for oxidative damage to DNA. METHODS: The pre-workshift and post-workshift urinary samples of 64 male workers in e-waste dismantling procedure were detected by solid-phase extraction-high performance liquid chromatography-electrochemical detector (SPE-HPLC-ECD). The data were statistically analyzed by two factors, age or smoking status. RESULTS: The 8-OHdG levels in non-smokers' urines (n = 42) were higher than those in smokers' urines (n = 22). The levels in pre-workshift urines were detected at (8.25 +/- 4.23) micromol/mol creatinine in non-smokers, while the values were (5.44 +/- 1.18) micromol/mol in smokers. And, the levels in post-workshift were detected at (43.12 +/- 16.19) micromol/mol creatinine in non-smokers, while the values were (14.82 +/- 2.51) micromol/mol in smokers. The 8-OHdG levels in pre-workshift urines were not different between non-smokers and smokers (t = -0.81, P = 0.42), however after 1 day exposure, urinary 8-OHdG levels were significantly increased in non-smokers than those in smokers (t = - 2.33, P < 0.05). On the other hand, the subjects were divided into five groups according to their age. The 8-OHdG levels in pre-workshift urines were (1.86 +/- 0.66), (3.57 +/- 0.54), (8.12 +/- 4.10), (11.39 +/- 3.70) micromol/mol creatinine in < 20 years group (n = 6), 20 -years group (n = 22), 30 - years group ( n = 23), 40 - 49 years group (n = 11) respectively. No effect of age was found on the pre-workshift urinary 8-OHdG levels (F = 0.98, t = 0.41). However, it was found that the post-workshift urinary 8-OHdG levels increased along with the e-waste workers' age (F = 4.81, P = 0.03), and they were (4.19 +/- 2.85), (19.89 +/- 5.26), (28.89 +/- 14.61), (34.94 +/- 12.50) micromol/mol creatinine in < 20 years group, 20 - years group, 30 - years group, 40 - 49 years group respectively. CONCLUSION: The urinary 8-OHdG levels in the e-waste dismantling workers might be inhibited by smoking status. The post-workshift urinary 8-OHdG levels increased along with the e-waste workers' age.

Simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry.

OBJECTIVE: To develop an analytical method for simultaneously qualitative and quantitative determination of melamine and triazine-related by-products including ammelide, ammeline, and cyanuric acid in milk and milk products by gas chromatography-tandem mass spectrometry (GC-MS/MS). METHODS: Melamine and triazine-related by-products namely ammelide, ammeline and cyanuric acid in the samples were extracted in a solvent mixture of diethylamine, water, and acetonitrile (10:40:50, V/V/V). After centrifugation, an aliquot of the supernatant was evaporated to dryness under a gentle stream of nitrogen gas, and then melamine and triazine-related by-products were derivatized using BSTFA with 1% TMCS. The derivatives of melamine and its analogues were determined by gas chromatography/tandem mass spectrometry using multiple reactional monitoring (MRM) with 2, 6-Diamino-4-chloropyrimidine (DACP) being used as an internal standard. RESULTS: The linear detectable ranges were from 0.004 mg/kg to 1.6 mg/kg for melamine, ammelide, ammeline, and cyanuric acid with a correlation coefficient no less than 0.999. The recovery rates of the four compounds in spiked blank milk powder at concentrations 0.5, 1, 2 mg/kg were between 61.4%-117.2%, and the relative standard deviation was no more than 11.5% (n=6). The detection limits of melamine, ammelide, ammeline and cyanuric acid in milk powder were 0.002 mg/kg with a ratio of signal to noise of 3. CONCLUSION: This GC-MS/MS method for simultaneous determination of melamine, ammelide, ammeline, and cyanuric acid in milk and milk products is sensitive and specific.

Dietary exposure assessment of Chinese adults and nursing infants to tetrabromobisphenol-A and hexabromocyclododecanes: occurrence measurements in foods and human milk.

Tetrabromobisphenol A(TBBPA) and hexabromocyclododecane diastereoisomers (alpha, beta, and gamma-HBCD) were determined in 24 pooled human milk samples and 48 Chinese total diet study (TDS) samples collected in 2007. On the basis of ultra performance liquid chromatography-mass spectrometry (UPLC-MS/MS) analysis, levels of TBBPA ranged from < LOD to 5124 pg/g lipid weight (lw) in human milk and from < LOD to 2044 pg/g lw in TDS samples. The alpha-HBCD diastereoisomer, which ranged from < LOD to 2776 pg/g lw in human milk and from < LOD to 2224 pg/g lw in TDS samples, was generally the most abundant isomer comparing with beta- and gamma-HBCD. The average estimated daily intake (EDI) of TBBPA via human milk for nursing infants with a range 320-37240 pg/kg bodyweight (bw)/day was 5094 pg/kg bw/day, while that of sigmaHBCD was 5837 pg/kg bw/day with a range 670-17320 pg/kg bw/day. The medium bound (< LOD = 1/2LOD) EDI(TBBPA) for a "reference" man via animal origin foods was 256 pg/kg bw/day and EDI(sigmaHBCD) was 432 pg/kg bw/day. Meat and meat products were the main source in the total dietary intake of TBBPA and sigmaHBCD. Our research on the estimated daily intake of TBBPA and sigmaHBCD by the Chinese population indicated large variations in TBBPA and sigmaHBCD levels between provinces. Overall, our data indicate the Chinese EDI was lowerthan the EDI from similar studies in Europe.

Elevated levels of urinary 8-hydroxy-2'-deoxyguanosine in male electrical and electronic equipment dismantling workers exposed to high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans, polybrominated diphenyl ethers, and polychlorinated biphenyls.

To investigate the occupational exposure levels to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated diphenyl ethers (PBDEs), and polychlorinated biphenyls (PCBs), indoor dust (n = 3) in workshops and hair samples from male workers (n = 64) were collected at two electrical and electronic equipmentwaste (E-waste) dismantling factories located in the LQ area in east China in July 11--13, 2006. Pre- and postworkshift urines (64 of each) were also collected from the workers to study oxidative damage to DNA using 8-hydroxy-2'-deoxyguanosine (8-OHdG) as a biomarker. The concentrations of PCDD/Fs, PCDD/F-WHO-TEQs, PBDEs, PCBs and PCB-WHO-TEQs were (50.0 +/- 8.1) x 10(3), 724.1 +/- 249.6, (27.5 +/- 5.8) x 10(6), (1.6 +/- 0.4) x 10(9), (26.2 +/- 3.0) x 10(3) pg/g dry weight (dw) in dust, and (2.6 +/- 0.6) x 10(3),42.4 +/- 9.3, (870.8 +/- 205.4) x 10(3), (1.6 +/- 0.2) x 10(6), 41.5 +/- 5.5 pg/g dw in hair, respectively. The homologue and congener profiles in the samples demonstrated that high concentrations of PCDD/Fs, PBDEs, and PCBs were originated from open burning of E-waste. The 8-OHdG levels were detected at 6.40 +/- 1.64 micromol/mol creatinine in preworkshift urines. However, the levels significantly increased to 24.55 +/- 5.96 micromol/mol creatinine in postworkshift urines (p < 0.05). Then, it is concluded that there is a high cancer risk originated from oxidative stress indicated by the elevated 8-OHdG levels in the E-waste dismantling workers exposed to high concentrations of PCDD/Fs, PBDEs, and PCBs.

Occurrence of chloropropanols in soy sauce and other foods in China between 2002 and 2004.

A survey of chloropropanols in soy sauce and some selected foods in China is reported. Thirty-seven traditionally brewed soy sauce samples contained 3-MCPD below the EC maximum limit (ML) of 0.02 mg kg(-1). All soy sauce samples (629) from retailers contained levels of 3-MCPD ranging between <0.005 (LOQ) and 189 mg kg(-1), and only 12.2% had levels in excess of the Chinese ML of 1.0 mg kg(-1) for acid hydrolyzed vegetable protein (acid HVP). This indicates that the necessary processing changes have been made to decrease levels of chloropropanols in soy sauce. 2-Monochloropropane-1,3-diol (2-MCPD), 1,3-dichloro-2-propanol (1,3-DCP) and 2,3-dichloro-1-propanol (2,3-DCP) were detected in 48.1 19.1 and 3.78% of the soy sauce samples, respectively; the highest levels being 20.3, 8.26 and 0.50 mg kg(-1), respectively. A good linear correlation was found between the amount of 3-MCPD and 2-MCPD, with the level of 3-MCPD being generally higher than that of other chloropropanols for the same soy sauce. Acid HVP contained 3-MCPD at a level of 0.010-117.7 mg kg(-1) (on a liquid basis) and 80% of samples contained levels exceeding 1.0 mg kg(-1). In some other foods investigated, relatively high levels of 3-MCPD were found in soy sauce powder, oyster sauce, beef products, instant noodle spices and health foods, ranging from 0.029 to 13.64 mg kg(-1). It is concluded that abnormal levels of 3-MCPD in soy sauce or other foods produced in China may result from acid hydrolysis or the addition of the contaminated acid HVP.

Dietary intake of polychlorinated dioxins, furans and dioxin-like polychlorinated biphenyls from foods of animal origin in China.

Four food groups of animal origin from the Chinese Total Diet Study (TDS) in 2000 were analysed for 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (PCBs). The samples were from four regions, covering 12 provinces of China. PCDD/Fs, expressed as WHO toxic equivalents (TEQ), ranged from 0.02 to 0.28 pg TEQ g-1 and dioxin-like PCBs ranged from 0.01 to 0.24 pg TEQ g-1 (wet weight, ND = LOD), in all samples. Using food consumption data from a 3-day household dietary survey, daily dietary intake of dioxin-like compounds from foods of animal origin in China was estimated. Daily intake among regions ranged 0.09-0.59 pg TEQ kg-1 body eight day-1.

Tag/anti-tag liquid-phase primer extension array: a flexible and versatile genotyping platform.

This study demonstrates an array-based platform to genotype simultaneously single nucleotide polymorphisms (SNPs) and some short insertions/deletions (indels) by the integration of the universal tag/anti-tag (TAT) system, liquid-phase primer extension (LIPEX), and a novel two-color detection strategy on an array format (TATLIPEXA). The TAT system permits a universal chip to be used for many applications, and the LIPEX simplifies the sample preparation but improves the sensitivity significantly. More importantly, all SNPs and some short indels can be interrogated in a single reaction with only two fluorescent ddNTPs. The concept of TATLIPEXA is demonstrated for nine SNPs (eight point mutations and one single-base insertion), and genotypes obtained show a remarkable concordance rate of 100% with both DNA sequencing and restriction fragment length polymorphism. Moreover, TATLIPEXA is able to provide quantitative information on allele frequency in pooled DNA samples, which could serve as a rapid screening tool for SNPs associated with diseases.

[Study on determination of polycholorinated biphenyls in fish by isotopedilution GC-LRMS].

OBJECTIVE: To develop a method for determination of 20 indicator polycholorinated biphenyls in fish by GC-LRMS. METHODS: Fish sample was added 13C lablled internal standard and cleaned-up by a multilayer silica column and a alumina column. Sample was analyzed by HRGC-LRMS using SIM mode. RESULTS: Detection limits of 20 indicator polycholorinated biphenyls were 0.009 - 0.044 ng/g. Average recovery were 79.7% - 112.6%, RSD were 1% - 8% (n = 6). CONCLUSION: Results showed that the method was suitable for determination of indicator PCB in fish sample.