ABSTRACT
Nonaqueous capillary electrophoresis-chemiluminescence (NACE) method was developed for the determination of five phenolic environmental estrogens including bisphenol A (BPA),4-nonylphenol(4-NP) ,4-tert-octylphenol(4-tOP),4-tert-butylphenol(4-tBP) and tetrabromobisphenol A(TBBPA) in food packaging material. Target compounds in soaking solution of food packaging material samples were separated by NACE-CL after derivatization with 4-(4,5-diphenyl-lH-imidazol-2-yl) benzoyl chloride ( DIB-Cl) ,reacted with per-oxyoxalate chemiluminescence system,and then detected through magnifying light signal with photomultiplier. With 17β-E_2 as internal standard,qualitative and quantitative analysis of the target compounds were performed by relative migration time and the ratio of relative chemiluminescence intensity,respectively. Several influence factors on separation with NACE,such as the composition and proportion of organic solvent,the concentration of electrolyte,temperature surrounding of the capillary,the concentration of acetic acid and work voltage,were investigated. And the peroxyoxalate chemiluminescence system was optimized. Under these conditions,4-tBP,BPA,4-OP,4-NP and TBBPA were all separated and showed good linearities in the ranges of 0.0095-3.0 mg/L,0.0087-3.0 mg/L,0.0085 -3.0 mg/L,0.011 -3.0 mg/L,0.009-3.0 mg/L,respectively,with correlation coefficients over 0. 9947. The RSDs of relative migration time and relative chemiluminescence intensity ratio were 0.9% -3.0% and 6.5% - 8.6%. Recoveries for the spiked samples ranged from 86.7% to 98. 8%. Five common food packaging material samples were analyzed. The proposed method is simple and sensitive for the quantitative determination of phenolic environmental estrogens in food packaging material samples.
ABSTRACT
Objective To develop a gas chromatography-mass spectrometric method(GC/MS) for simultaneous determination of environmental estrogens including 4-nonylphenol,bishphenol A,diethylstilbestrol and 17?-ethinylestradiol and endogenic estrogens including 17?-estradiol,17?-estradiol,estriol and estrone in mutton. Methods Mutton samples were extracted using a mixture of acetonitrile-ethyl acetate(3∶2,V/V) and cleaned up by florisil cartridge. Derived with pentafluoropropionic anhydride(PFPA) ,the derivatives were determined by GC-MS. Results The linear range of determination was 0.2-5.0 ?g/kg. The intraday relative standard deviations of the peak area were 1.25%—5.85% and the detection limits ranged from 0.024 to 1.40 ?g/kg,and the rates of recovery ranged from 71.5%—111.0% except for 17?-ethinylestradiol( 55.4%) . Conclusion This method is simple,rapid,accurate and applicable to the determination of trace environmental estrogens in mutton
ABSTRACT
Surfactants are employed widely in household and industryial products wordwide.Everyday millions pounds surfactants and their products are dispersed into soil, water, food and human body that posing a threat to human health. The paper expatiated on the topic that the threats of surfactants on food safety with arguments as: acute toxicity, genetic toxicity, estrogenic effects, bioconcentrate and so on. At last, the article emphasized it is essential to have comprehensive study on the surfactants toxicity and influence on food safety.
ABSTRACT
The reproductive toxicity of environmental estrogens(EEs)has become an extensively studied subject in environmental science and reproductive medicine nowadays.Many epidemiology data and experimental evidences indicated that EEs may significantly cause the disorders of male sex differentiation such as microphallus,hypospadia,cryptorchidism and masculinization behavior disorder and so on.The mechanism includes estrogenic activity,anti-androgenic activity as well as other feedback regulation and signal transmission which influence hormones metabolism.
ABSTRACT
The conception,sources and research focus on environmental estrogens of effluent from sewage treatment plants were briefly introduced and the advances on environmental estrogens of effluent from sewage treatment plants were reviewed in the present paper.The study and applications of biomarker-vitellogenin (Vtg) was also discussed.The future research direction of environmental estrogens was proposed.
ABSTRACT
Objective To explore the effects of maternal exposure to dibutyl phthalate ( DBP) ,an environmental estrogen on the proliferation and differentiation of neural stem cells ( NSCs) in the neural tube of neonatal rats. Methods A total of 40 male and 40 female SD rates at age of 4 to 5 months,were matched,and the morning when vaginal plugs were found was designated as E0. Then the 40 pregnant rats were randomly divided into 4 groups,3 DBP exposure groups ( 25,75,and 225 mg/kg) and control group. DBP at corresponding doses were dissolved in corn oil,and administrated by intragastrically injection once per day from E0 till delivery,while those of control group were given corn oil. Brain tissue of newborn rats was collected for primary culture of NSCs. Then the cell colony formation was counted to detect the NSCs proliferation. Then 10% fetal bovine serum ( FBS) was added into the culture medium to induce the NSCS to differentiate. Neu-N and GFAP immunofluorescence stainings were used to detect neurons and astrocytes,and their morphological changes were observed. Results The proliferation of NSCs was decreased significantly after DBP administration. Compared with the control group ( 40. 53 ? 4. 65) % ,the colony formation rate of middle-and high-dose DBP exposure groups was significantly reduced and in a dose-dependent manner ( 30. 96 ? 3. 80) % ,( 15. 35 ?5. 29) %,( 6. 58 ?1. 43) %,P
ABSTRACT
Objective To establish the recombinant yeast estrogen system(RYES),a reporter vector controlled by estro-gen response elements(ERE)in yeast was constructed.Methods pLacZi-1RER was obtained first by inserting an ERE which was synthesized artificially into the yeast reporter vector pLacZi which had already been lined by SalI and the terminal dephos-phorized by CIAP.Then,pLacZi-zERE.was obtained by inserting another ERE into the XhoI site nearby the ERE in pLacZi-1ERE.Results Sequence analysis indicated that the yeast reporter vector controlled by two tandem copies of ERE was con-structed successfully.Conclusion The yeast reporter vector controlled by ERE,pLacZi-2ERE,was constructed successfully,which was the very important groundwork for further establishment of the recombinant yeast estrogen system(RYES).
ABSTRACT
Objictive The estrogen_like activities of environmental estrogens mediated by estrogen receptor (ER) may be assayed through measuring the expressed product of the reporter gene in the recombinant yeast. Methods The recombinant yeast YM_ADER_ERE was obtained by transformation of pGAD_hER and pLacZi_2ERE, the yeast expression vector of full_length human ER cDNA and reporter vector controlled by estrogen response element (ERE) which were constructed successfully in the lab, by means of the lithium acetate method. Results The activity of ?_galactosidase, the expressed product of the reporter gene lacZ in the yeast YM_ADER_ERE, increased significantly when added in the natural estrogen 17?_estradiol (E2) compared to DMSO. In the experiment with E2 at the final concentration of 10-15 to 10-7 mol/L, the maximum effect (EAmax) and the median effect concentration (EC50) of E2 in the yeast were 94.31 U and 0.34 nmol/L respectively. Conclusion The expression of the reporter gene in the recombinant yeast was dependent on the estrogen ligand, which met with the design idea and requirement of the assay system for environmental estrogens and indicated preliminarily that the recombinant yeast estrogen system (RYES) was established successfully.