高效液相色谱荧光法测定贵阳市市售腊肉中苯并[a]芘含量

建立高效液相色谱法测定腊肉中苯并[α]芘(简称BaP)的测定方法。通过先超声提取,后皂化的处理,采用迪马C18色谱柱(250mm×4.6mm,5μm);乙腈-水为流动相;荧光检测器,激发波长为385 nm;检测波长为405nm;苯并[a]芘在(0.005-1.0μg/mL)范围呈线性,其线性回归方程为:Y=1.8×107x+11012;相关系数R=0.9992;苯并[a]芘在0.0035、0.0070、0.0105μg 3个添加浓度水平上的回收率为(83.08%、88.67%、84.54%)。本法色谱条件易于掌握,测得数据重复性好,线性关系好,精密度和准确度均能满足分析要求。同时本文对贵阳市主要市售腊肉中苯并[α]芘(BaP)含量进行了测定,结果含量在1.04~4.16μg?kg之间,表明传统的油炸食品安全性使人的健康受到不同程度的影响。     

苯并(a)芘对体外培养人淋巴细胞免疫活性和HSP70的影响

不同浓度苯并(a)芘[B(a)P](0.125、0.250、0.500、1.000、2.000、4.000、8.000、16.000 μmol/L)处理体外培养的人淋巴细胞系721.221,研究B(a)P对体外培养的人淋巴细胞免疫活性和热休克蛋白70的影响.染毒16 h,分别应用MTT比色法、Elisa法和Western blot法研究B(a)P对体外培养的淋巴细胞细胞活力、细胞因子IFN-α、interleukin-1α和interleukin-6分泌和热休克蛋白70表达情况的影响.与对照组比较,0.125～1.000μmol/L低剂量B(a)P染毒组促进细胞的生长(P＜0.05),1.000 μmol/L B(a)P染毒组细胞的增殖活性达到峰值,与溶剂对照组相比,增加了55％.2.000～ 16.000 μmol/L B(a)P染毒细胞,16 h后对细胞活力存在显著抑制作用(P＜0.05).IFN-α随着B(a)P染毒浓度的升高,IFN α分泌呈先上升后下降的趋势,1 μmol/L B(a)P染毒组分泌达到峰值,随后降低.IL-1α和IL-6分泌随着染毒浓度的增加而降低,与对照组相比有统计学意义(P＜0.05),呈现剂量-效应关系.HSP70随着染毒浓度的增加,呈现先增加后降低的趋势.本研究证实B(a)P对721.221细胞活力、免疫活性和应急因子的影响存在显著的剂量依赖性,为今后评估人群接触B(a)P对免疫系统和自身应急系统的毒性提供实验依据.     

混合菌固定化及其对土壤中芘和苯并芘的降解

从石油污染土壤中筛选出1株细菌(Bacillus sp.)和1株真菌(Mucor sp.),以12种不同材料为载体对混合菌进行固定化,研究了固定化混合菌的降解特性.结果表明,采用吸附法能有效实现混合菌在改性后蛭石上的固定化.制得的固定化混合菌,传质性能好,对芘(Pyr)和苯并芘(BaP)的降解率42 d分别可达94.96%和74.96%,明显高于游离菌对Pyr和BaP的降解率60.49%和50.09%.采用扫描电子显微镜(SEM)观察了固定化混合菌微观结构,同时探讨了固定化混合菌的传质过程     

固相萃取—高效液相色谱法测定植物油中苯并(a)芘

本实验建立了基于固相萃取的高效液相色谱法测定植物油中苯并(a)芘含量。样品用正己烷溶解,经Cleanert BAP-3固相萃取小柱净化,采用C18色谱柱分离,以乙腈/水=80/20(V/V)为流动相,经荧光检测器检测。结果表明苯并(a)芘在0.50μg/L~50μg/L浓度范围内线性良好,相关系数为0.9999,方法检出限为0.1μg/kg,样品加标回收率为89.00%~94.46%,RSD为1.0%~2.2%。该方法具有快速、准确、灵敏、简单等特点,可用于植物油中苯并芘的检测。     

Effects of 2,3,7,8-TCDD and benzo[a]pyrene on modulating vitellogenin expression in primary culture of crucian carp （Carassius auratus） hepatocytes

Vitellogenin (Vtg) is the precursor of yolk protein. Its expression and secretion are estrogen-regulated and are crucial for oocyte maturation. An in ritro xenoestrogen screening model was established by measuring Vtg induction in cultured primary hepatocytes from crucian carp. Vtg production was detected by biotin-avidin sandwich ELISA method while Vtg and cytochrome P4501A1 (CYP1A1) mRNA induction were measured by semi- quantitative PCR-primer dropping technique. Vtg and Vtg mRNA were dose-dependently induced by diethylstilbestrol (DES, 0.2-200 ng/mL) in hepatocytes of crucian carp. Co-treatment of the DES-induced hepatocytes with either 2,3,7,8-TCDD (TCDD, 0.1-4 pg/mL) or benzo[a]pyrene (B[a]P, 5-1000 ng/mL) resulted in a reduction of Vtg production and an increment of CYP1A1 mRNA expression both in a dose dependent manner, indicating the anti-estrogenic effects of the compounds. However, at lower tested concentrations, TCDD (0.1, 0.2 pg/mL), B[a]P (5 ng/mL)seemed to have a potentiating effect on Vtg expression and secretion, although by their own these compounds had no observable estrogenic effect on Vtg induction. Tamoxifen (a selective estrogen receptor modulators, 1 nmol/L-1μmol/L),and β-naphtho-flavone (β-NF, an aryl hydrocarbon receptor inducing compounds, 2.5-1000 ng/mL) also were employed to study the possible interactions in DES-induced Vtg expression. In co-treatment of the DES-induced hepatocytes with β-NF or tamoxifen, the decrease in Vtg production did parallel induction of CYP1A1 for β-NF, but tamoxifen inhibited Vtg induction did not parallel induced CYP1A1 expression in all test concentrations. On the contrary, it was found that in co-treatment of the TCDD-induced hepatocytes with DES, TCDD induced CYP1A1 mRNA production was inhibited by DES also. These results implicated a possible cross talk between estrogen receptor- and aryl hydrocarbon receptor-mediated pathways in the hepatocytes.     

Simple Synchronous Fluorimetric Method for Determination of Benzo[a] pyrene in Airborne Particulates without a Pre-Separation Procedure

A sensitive analytical method, constant-energy synchronous fluorimetry, has been used to determine benzo[a]pyrene （BaP） selectively in airborne particulates （AP）. A constant-energy difference of 1 400 cm^-1 was selected for obtaining single spectral peak. The method could easily identify BaP in an 18-component polycylic aromatic hydrocarbons（PAHs） mixtures. Calibration plots in methanol solution and in sodium dodecylsulfate （SDS） micellar media show a good linearity （R〉0.999） in the BaP concentration range generally fotund in the environment. The method gives a detection limit of 0.40 nmol/L in SDS micellar medium and 1.34 nmol/L in methanol solution.