The contents of tea polyphenolic compounds, ascorbic acid, flavones and tea catechins in 17 kinds of Chinese tea were reported.In multivariable analysis, both factor analysis and regression technique were used to assess the realationship between blocking rate (transferred into In odd, dependent variable) and tea active constituents (independent variable) . It has been shown that the correlation coefficient between each pair of independent variables is comparatively high. One main factor could explain 80% of variation among independent variables, of which the factor loadings were 0.951 (tea catechins), 0.88 (tea polyphenolic compounds), 0.842 (ascorbic acid). It has been found that tea polyphenolic compounds had a higher contribution to the blocking rate. The blocking rates on NPRO formation were 88% for 2 ml green tea extract, 74% for tea polyphenolic compounds extracted from 2 ml green tea, and 75% for 20 mg of tea catechins, the same amount as contained in 2ml of tea extract. The blocking rate -was 28% for the same amount of ascorbic acid contained in 2 ml of tea extract, and therefore ascorbic acid in tea didn't play an important role in the blocking of NPRO formation. Tea polyphenolic compounds and tea catechin affected NPRO formation in the same manner as tea extract, i.e. inhibtion in higher level and promotion in lower level. Thus, it might be concluded that blocking effect on NPRO formation was mainly due to tea polyphenolic compounds especially tea catechin in tea.

A method was established for the simultaneous determination of the total fatty acid esters of chloropropanols in edible oils by gas chromatography-mass spectrometry combined with isotope dilution technology. The samples were hydrolyzed with sodium methylate-methanol, and then purified by diatomite cartridge. After being derivatized with heptafluorobutyrylimidazole ( HFBI ), the target analytes were determined by GC-MS with the deuteriumchloropropanols esters as the internal standards. An excellent linear correlation in the range of 0. 050-2. 000 mg / L was acquired for 3-monochloropropane-1,2-diol (3-MCPD) esters, 2-MCPD esters, dichloropropan-2-ol (1,3-DCP) esters and 2,3-dichloropropan-1-ol (2,3-DCP) esters, with all the correlation coefficients (r) higher than 0. 9995. The limits of detection (LODs) for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters were 0. 015, 0. 015, 0. 030, and 0. 030 mg / kg, respectively, and the limits of quantitation (LOQ) were 0. 050, 0. 050, 0. 100, and 0. 100 mg / kg, respectively. The average spike recoveries of the four kinds of chloropropanols esters in blank extra virgin olive oil matrix were typically in a range of 87. 0% -110. 5% with the relative standard deviations (RSDs) less than 10. 1% . The detection rates of 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters in 74 edible oil samples were 94. 6% , 63. 5% , 5. 4% , and 0% , respectively. The contamination levels of 3-MCPD esters, 2-MCPD esters and 1,3-DCP esters were in the range of not detected (ND) to 10. 646 mg / kg, ND to 3. 617 mg / kg and ND to 0. 089 mg / kg, respectively. This method is accurate and rugged for the simultaneous determination of total fatty acid esters of chloropropanols in edible vegetable oils.

OBJECTIVETo assess the exposure level of total N-nitroso compounds (TNOCs) in the residents of high- and low-risk areas for esophageal cancer in southern China.

METHODSSamples of duplicate plate diets and 12 hr overnight urine were collected from 120 male adults in each of the 2 areas, a high-risk area (Nanao county) and a low-risk area (Lufeng county) for esophageal cancer. The 240 male healthy subjects (35 - 64 years old) were selected by a 3-stage random cluster sampling procedure. Levels of TNOC, N-nitrosamino acids (NAAs) and volatile N-nitroso compounds (VNOC) in the samples were measured by Thermo Energy Analyzer.

RESULTSThe detectable rate (95%) of diet TNOC, daily dietary TNOC intake (4.25 +/- 0.84) micromol/day, 12-hr urinary TNOC excretion levels (1.76 +/- 0.23 ng/12 h) and daily dietary intake of VNOC (266 +/- 31.2 microg/day) in the high-risk area were all significantly higher than those of the low-risk area. Oesophageal cancer mortality rates were positively and significantly associated with daily dietary TNOC intake and 12-hr urinary TNOC excretion. Urinary NAAs excretion levels were not different in the two areas.

CONCLUSIONThe results suggest that TNOCs may be implicated in the etiology of esophageal cancer in southern China.

Adult ; China ; Esophageal Neoplasms ; etiology ; mortality ; Humans ; Male ; Middle Aged ; Nitroso Compounds ; administration & dosage ; adverse effects ; urine

The intestinal microecosystem is composed of natural microflora, intestinal epithelial cells, and intestinal mucosal immune system. Nonalcoholic fatty liver disease (NAFLD) is a metabolic stress-induced liver injury associated with insulin resistance and genetic susceptibility. In recent years, there has been increasing evidence showing the involvement of imbalanced intestinal microflora in the pathogenesis of NAFLD. Overgrowth of intestinal microflora, increased permeability of intestinal mucosa, intestinal endotoxemia, and production of inflammatory cytokines play important roles in the development of NAFLD. Further studies on the relationship between intestinal microflora imbalance and the pathogenesis of NAFLD may shed light on the treatment and prevention of NAFLD.

Objective To investigate auditory sensory gating potential in the siblings of schizophrenic, to discover the neuroimaging features of sensory gating associated with schizophrenia as intermediate phenotypes. Methods Twelve siblings of schizophrenia patients in the first episodic, and 12 healthy controls matched in gender, age, education under?went MRI scan when performing a auditory sensory gating fMRI task (repeated clicks and single click auditory stimuli). The measure of sensory gating was the contrast of repeated clicks minus single click. The analysis of result was imple?mented in SPM2. Results Compared with healthy controls, schizophrenia patients showed significant overactivation in the right inter cingulate gyrus (x=4,y=8,z=32) and left anterior cingulate gyrus (x=-8,y=4,z=28) during the fMRI senso?ry gating task. Conclusion Sensory gating is overactivated in the cingulate gyrus in siblings of schizophrenic. This pat?tern may be a potential endophenotype of schizophrenia.

Objective:To evaluate the application of PG-SGA,NRS 2002 and BIA in nutritional assessment and screening of patients with gynecologic cancers.Methods:118 patients were randomly selected.Nutritional status were evaluated by PG-SGA,NRS 2002 and BIA,and consistency between each tools were compared.Results:The prevalence of malnutrition or nutritional risk of patients were 64.4％ (PG-SGA),57.6％ (NRS 2002),and 33.9％ (BIA) respectively.In all patients,the consistency of PG-SGA and NRS 2002 was high (P ＜ 0.001),while there were not significantly consistent between BIA and PG-SGA,or between BIA and NRS 2002 (P ＜ 0.001).Conclusion:According to the evaluation of PG-SGA or NRS 2002 in gynecologic patients,the prevalence of malnutrition or nutritional risk is high,and these two scales are suitable for nutritional assessment and screening of gynecologic cancer patients,especially in ovarian cancer patients.In addition,BIA may be a promising tool to evaluate cervical cancer patients' nutritional status.

OBJECTIVETo establish a comprehensive analytical method based on SPE-UPLC-MS for the simultaneous determination of bisphenol A (BPA), nonylphenol (NP), and octylphenol (OP) in urine samples.

METHODSSixty urine samples collected from healthy subjects were analyzed for BPA, NP, and OP concentrations. The samples were de-conjugated by adding β-glucuronidase and sulfatase. After the enzymatic treatment, the samples were subjected to the OASIS HLB column solid phase extraction cartridges so as to be cleaned and concentrated. The UPLC separation was performed on a Acquity UPLCTM BEH C18 column (2.1×100 mm, 1.7 μm) with a gradient elution system of methanol-water as the mobile phase. Triple-quadrupole mass spectrometry analyzer was used for the qualitative and quantitative analysis of UPLC-MS/MS system.

RESULTSThe limit of detection of BPA, NP, and OP was 0.10, 0.10, and 0.15 ng/mL, respectively. The recoveries of BPA, NP and OP were 80.1%-108%, 81.3%-109%, and 81.5%-98.7%, respectively. Among the 60 urine samples, BPA was detected in 8 samples at the level of 0.297-32.7ng/mL, NP was detected in 29 samples at the level of 1.69-27.8 ng/mL, and OP was detected in 17 samples at the level of 0.407-11.1 ng/mL.

CONCLUSIONThe method is simple with high sensitivity and selectivity, and is suitable for the determination of BPA, NP, and OP in urine. As shown by our analysis, BPA, NP, and OP appear to be prevalent in human urine. This is particularly true for NP. The results from our study is therefore valuable for future studies to assess the exposure to BPA, NP, and OP in the general population.

Benzhydryl Compounds ; Chromatography, Liquid ; methods ; Humans ; Mass Spectrometry ; methods ; Phenols ; urine ; Reference Values ; Solid Phase Extraction ; methods

OBJECTIVEWe established a method of UPLC-MS/MS that was to detect fifteen precursors of perfluoroalkyl sulfonates (PFSA) and perfluoroalkyl carboxylates (PFCA) in serum.

METHODSBriefly, TBAS solution was added to sera, then the mixed solution was extracted with aliquots of MTBE. The MTBE aliquots were combined, evaporated to dryness under nitrogen, and reconsituted in 0.25 ml of methanol and water (1:1). Then the reconstituted solution through 0.2 µm nylon syringe filter was collected. Chromatographic separation was performed using a Waters ACQUITY (TM) BEH ¹⁸C column (50 mm × 2.1 mm × 1.7 mm). Analyte quantitation was performed in the negative electrospray ionization mode and multiple reaction monitoring (MRM).

RESULTSThree target substances, 6: 6PFPi, 6: 8PFPi, 8: 8PFPi, were externally confirmed by standard addition. Rates of recovery for these three chemicals were from 41.01% to 112.13% in two standard levels. And the relative standard deviations (RSD) were lower than 11.63% and higher than 1.80%. The other twelve substances were quantified with internal standard. Moreover in two standard levels, rate of recovery for these chemicals ranged from 70.25% to 127.51%. And RSD were more than 1.23% and less than 15.45%. And the corresponding limit of detection (LOD) and limit of quantitation (LOQ) for all target substances were 0.1-5.0 pg/ml and 0.2-10.0 pg/ml. Then we detected these target substances in ten different human serum samples. The levels of few substances were higher than LOD. And the ranges of FOSA-M, N-EtFOSA-M, N-MeFOSAA, N-EtFOSAA were respectively < LOD-0.94 pg/ml, < LOD-10.08 pg/ml, < LOD-6.74 pg/ml, < LOD-1.04 pg/ml.

CONCLUSIONThe method, with high sensitivity and accuracy, could meet the actual testing requirements.

Caprylates ; Fluorocarbons ; Humans ; Limit of Detection ; Tandem Mass Spectrometry

OBJECTIVETo establish a method for determination of fatty acid esters of chloropropanols (chloropropanols esters) in milk powder by isotope dilution-gas chromatography-mass spectrometry (GC-MS), and to acquire the pollution level of chloropropanols esters in infant formula and evaluate the dietary exposure risk of chloropropanols esters in infant formula for infants.

METHODSA total of 111 infant formula samples were collected from supermarkets in Beijing, and the infant formula with no chloropropanols esters detected was served as the blank sample. The samples were ultrasonically extracted with hexane, followed by ester-bond cleavage reaction with sodium methylate-methanol and purification by matrix solid-supported liquid-liquid extraction, then being derivatived with heptafluoro butyrylimidazol. After extracted by sodium chloride solution, the derivatives were determined by GC-MS. The concentration of chloropropanols esters were quantified using the deuterium chloropropanols esters as the internal standards. The accuracy of the method was assessed by the recoveries of the blank spiked samples, and the relative standard deviations (RSD) of the recoveries represent the precision of the method. The contamination level of chloropropanols esters and the intake amount of the infant formula of the 6-month infant were used to estimate the dietary exposure assessment, and x (95% CI) and P97.5 of the contamination level of chloropropanols esters were used to represent the average dietary exposure and the high-end dietary exposure.

RESULTSThe satisfied linear correlations in the range of 0.010-0.800 mg/L was acquired for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters with coefficient correlations of 0.999 9, 0.999 8, 0.999 5 and 0.999 6, respectively. The limits of detection (LOD) and the limits of quantitation (LOQ) for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters were 0.005, 0.005, 0.015, 0.015 mg/kg, and 0.015, 0.015, 0.045, 0.045 mg/kg. The average recoveries of the four chloropropanols esters spiked at 0.025, 0.050 and 0.100 mg/kg in blank matrix were in a range from 80.3% to 111.9%, with relative standard deviations (RSD) less than 11.4%. Of the 111 infant formula samples, the detection rates and the contamination levels of 3-MCPD esters and 2-MCPD esters were 77.5% (86/111), 11.7% (13/111) with the contamination levels in the range of ND-0.230 mg/kg and ND-0.039 mg/kg, respectively, and χ (95% CI) and P97.5 of 3-MCPD esters and 2-MCPD esters were 0.020 (0.003-0.113) and 0.006 (0.005-0.025) mg/kg, 0.113 and 0.025 mg/kg, respectively. 1,3-DCP esters and 2,3-DCP esters were not detected in the 111 samples. x (95% CI) and P75 of the six-month old infants to 3-MCPD esters were 0.304 (0.038-1.735) and 1.735 µg · kg⁻¹ · d⁻¹, respectively, which accounted for 15.2% and 86.7% of the PMTDI (2 µg · kg⁻¹ · d⁻¹) of 3-MCPD.

CONCLUSIONThis GC-MS method was accurate and rugged for the determination of chloropropanols esters in milk powder. Based on the exposure assessment results, the health risk of chloropropanols esters for infants caused by the intake of infant formula was acceptable.

Chlorohydrins ; Esters ; Fatty Acids ; Food Contamination ; Gas Chromatography-Mass Spectrometry ; Humans ; Infant ; Infant Formula ; alpha-Chlorohydrin

OBJECTIVEParticulate samples from the atmosphere in an electronic waste dismantling area were collected to investigate the levels and sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs).

METHODSParticulate samples including total suspended particulates (TSP) and particulate matter <2.5 μm diameter (PM(2.5)) were collected on selected non-rainy days in summer (Jul 10-12, 2006) and winter (Jan 11-13, 2007) from Fengjiang (FJ), an electronic waste (e-waste) dismantling area in eastern China, and an adjacent area Luqiao (LQ). The samples were analyzed by isotope dilution - high resolution gas chromatography / high resolution mass spectrometry (HRGC/HRMS).

RESULTSIn FJ, the mean PCDD/F concentrations (mean TEQ values) were 280.6 pg Nm(-3) (3.432 pg WHO-TEQ Nm(-3)) for the TSP samples and 223.3 pg Nm(-3) (3.180 pg WHO-TEQ Nm(-3)) for the PM(2.5) samples. The total PCDD/F concentrations and TEQs in the PM(2.5) samples were about 66.8%-108.0% of the TSP samples, indicating that the fine particles contained higher levels of PCDD/Fs than coarse particles. The PCDD/F levels in FJ were much higher than those detected in common urban areas around the world, suggesting that the study area was heavily polluted by PCDD/Fs. Furthermore, the total average daily PCDD/F intake in FJ was estimated at 62.11 pg WHO-TEQ kg(-1)·day(-1) for adults and 110.11 pg WHO-TEQ kg(-1)·day(-1) for children, which greatly exceeds the WHO (1998) tolerable daily intake of 1-4 pg of WHO-TEQ kg(-1)·day(-1).

CONCLUSIONThe PCDD/F homologues and congener profiles confirmed that the PCDD/Fs in FJ originated from crude e-waste recycling activities. The severe dioxin pollution present in FJ has also substantially influenced the adjacent area of LQ through atmospheric transport. Open burning of medical waste was another source of PCDD/Fs identified in LQ.

Air Pollutants ; chemistry ; Atmosphere ; Benzofurans ; chemistry ; China ; Dibenzofurans, Polychlorinated ; Electronic Waste ; Environmental Exposure ; Humans ; Inhalation Exposure ; Occupational Exposure ; Particulate Matter ; chemistry ; Polychlorinated Dibenzodioxins ; analogs & derivatives ; chemistry ; Refuse Disposal ; methods ; Seasons