高效液相色谱法测定印染废水中微量三氯生

建立了一种快速、高效、准确的测定印染废水中三氯生的分散固相萃取-高效液相色谱分析方法。样品经聚酰胺粉末吸附和富集后,用5%氨水甲醇洗脱,考察了聚酰胺粉末吸附和富集的时间、吸附剂用量等因素对三氯生回收率的影响。结果显示,三氯生在0.05~5.0 mg/L的质量浓度范围内呈良好的线性关系,最低检出限LOD为0.01 mg/L,定量检出限LOQ为0.05 mg/L,方法回收率在93.0%~101.5%之间,RSD为5.4%~8.3%,能满足印染废水中三氯生的测定要求。     

基于固相萃取-高效液相色谱法的纺织品中三氯生的测定

建立了纺织品中三氯生的固相萃取-高效液相色谱检测方法。样品经超声提取后,用固相萃取进行净化,Kromasil C18 柱（250 mm × 4.6 mm i.d., 5 μm）分离,采用水/乙腈 (15/85, V/V)为流动相,紫外检测波长为280 nm,外标法定量。实验结果显示：样品中的三氯生在0.1~20.0 mg/kg的浓度范围内呈良好的线性关系,最低检出限LOD为0.01mg/kg,定量检出限LOQ为0.05 mg/kg 。方法回收率在94.0%~100.4%之间,RSD 为2.0%~4.4% 。本方法简便、快速、专属性强、干扰少,能满足纺织品中三氯生的测定要求。     

基于液相色谱-串联质谱法纺织品中三氯生的普查分析

建立了液相色谱-串联质谱法（LC-MS/MS）测定五大类纺织品中三氯生的检测方法,并对市场上随机抽取的15种样品进行了普查分析。样品采用三氯甲烷超声提取,提取后的溶液经过滤、浓缩后,采用LC-MS/MS检测,选择离子模式（SIM）扫描,外标法定量。该方法的在0.01～0.5?g/mL范围内有很好的线性关系,线性方程为：y=3.5e4x-994,线性相关系数为0.9998,方法的测定低限为0.025 mg/L,平均回收率为85.6～107.2 %,相对标准偏差小于7.0%。在所有样品中仅有2个样品检出,表明在纺织品中仍会添加三氯生。     

Preservation of sliced ham through triclosan active film

Active packaging is an alternative to preserve perishable food. In this work, polyethylene antimicrobial active films containing different levels of triclosan (0, 2000 and 4000 mg kg^?1) were developed by extrusion. The films' efficacies were evaluated against Escherichia coli, Staphylococcus aureus, Listeria innocua, Salmonella choleraesuis and Pseudomonas aeruginosa growth using agar diffusion test and by monitoring the inhibition of E. coli and S. aureus inoculated on sliced cooked ham. The mechanical characteristics of the films were also evaluated with Universal Test Machine (Instron). The incorporation of triclosan did not affect the mechanical properties of antimicrobial films compared to the control film. The average film thickness was 82.0 µm and the tensile strength and elongation to break were 30.3 N and 46.2%, respectively. Films containing triclosan showed an antimicrobial effect in vitro against E. coli and S. aureus, with formation of an inhibition halo for both. However, this result was not observed for L. innocua, S. choleraesuis and P. aeruginosa, although, a decrease in colony density occurred around the film for both incubation temperatures (7 ± 2°C and 35 ± 2°C). Sliced ham packed with the antimicrobial films showed a reduction of 1.5 logarithmic cycles in comparison to ham in contact with a control film after 12 days of storage at 7 ± 2°C, for E. coli and S. aureus. Antimicrobial films present potential for application as active packaging materials, as they showed effective against some pathogenic microorganisms that can be transmitted by foods. Copyright © 2009 John Wiley & Sons, Ltd.     

聚丙烯腈抗菌复合纳米纤维膜的制备及其抗菌性能

为研究分析不同抗菌剂对聚丙烯腈(PAN)抗菌纳米纤维的影响,进一步开发功能性纳米纤维纺织品,通过静电纺丝方法制备PAN/三氯生(TCS)、PAN/TiO₂抗菌复合纳米纤维膜,借助扫描电子显微镜、傅里叶红外光谱仪等对纳米纤维膜的微观结构和性能进行表征。结果表明:相对于纯 PAN纳米纤维膜,PAN/TCS 和PAN/TiO₂抗菌纳米纤维膜的纤维直径减少了39% ~ 71%,拉伸强度增加了12% ~ 88%; PAN/TCS 复合纳米纤维膜对金黄色葡萄球菌和大肠杆菌的抑菌圈都大于1 mm;由于TiO₂为非溶出型菌剂,PAN/TiO₂复合纳米纤维未发现抑菌圈;PAN/TCS 和PAN/TiO₂纳米纤维对金黄色葡萄球菌和大肠杆菌的抑菌率都达到了91.98%以上,且抑菌率随着TCS和TiO₂质量分数的增加而增加。     

Biological Evaluation of Potent Triclosan‐Derived Inhibitors of the Enoyl–Acyl Carrier Protein Reductase InhA in Drug‐Sensitive and Drug‐Resistant Strains of Mycobacterium tuberculosis

New triclosan (TRC) analogues were evaluated for their activity against the enoyl–acyl carrier protein reductase InhA in Mycobacterium tuberculosis (Mtb). TRC is a well‐known inhibitor of InhA, and specific modifications to its positions 5 and 4′ afforded 27 derivatives; of these compounds, seven derivatives showed improved potency over that of TRC. These analogues were active against both drug‐susceptible and drug‐resistant Mtb strains. The most active compound in this series, 4‐(n‐butyl)‐1,2,3‐triazolyl TRC derivative 3 , had an MIC value of 0.6 μg mL^?1 (1.5 μM ) against wild‐type Mtb. At a concentration equal to its MIC, this compound inhibited purified InhA by 98 %, and showed an IC₅₀ value of 90 nM . Compound 3 and the 5‐methylisoxazole‐modified TRC 14 were able to inhibit the biosynthesis of mycolic acids. Furthermore, mc²4914, an Mtb strain overexpressing inhA, was found to be less susceptible to compounds 3 and 14 , supporting the notion that InhA is the likely molecular target of the TRC derivatives presented herein.     

高效液相色谱法测定洗涤用品中的三氯生

建立了洗涤用品中三氯生的高效液相色谱(HPLC)测定方法。以二氯甲烷为提取溶剂,采用超声提取法提取洗涤用品中的三氯生,用配有紫外检测器的高效液相色谱仪进行测定,流动相为V(甲醇)∶V(水)=90∶10,紫外检测波长为282 nm。当三氯生浓度在0.5~100 mg/L时,其HPLC峰面积与其浓度呈良好的线性关系。三氯生的检出限(3S/N)为0.1 mg/L,加标回收率在96.2%~104.3%之间,相对标准偏差为1.2%~4.4%。该方法准确、灵敏、快速、重复性好,能满足洗涤用品中三氯生定量分析的要求。     

Chemical Conversion Pathways and Kinetic Modeling for the OH-Initiated Reaction of Triclosan in Gas-Phase

As a widely used antimicrobial additive in daily consumption, attention has been paid to the degradation and conversion of triclosan for a long time. The quantum chemistry calculation and the canonical variational transition state theory are employed to investigate the mechanism and kinetic property. Besides addition and abstraction, oxidation pathways and further conversion pathways are also considered. The OH radicals could degrade triclosan to phenols, aldehydes, and other easily degradable substances. The conversion mechanisms of triclosan to the polychlorinated dibenzopdioxin and furan (PCDD/Fs) and polychlorinated biphenyls (PCBs) are clearly illustrated and the toxicity would be strengthened in such pathways. Single radical and diradical pathways are compared to study the conversion mechanism of dichlorodibenzo dioxin (DCDD). Furthermore, thermochemistry is discussed in detail. Kinetic property is calculated and the consequent ratio of k_add/k_total and k_abs/k_total at 298.15 K are 0.955 and 0.045, respectively. Thus, the OH radical addition reactions are predominant, the substitute position of OH radical on triclosan is very important to generate PCDD and furan, and biradical is also a vital intermediate to produce dioxin.     

Triclosan Derivatives: Towards Potent Inhibitors of Drug‐Sensitive and Drug‐Resistant Mycobacterium tuberculosis

Overcoming resistance : Isoniazid (INH) is a frontline antitubercular drug that inhibits the enoyl acyl carrier protein reductase InhA. Novel inhibitors of InhA that are not cross‐resistant to INH represent a significant goal in antitubercular chemotherapy. The design, synthesis, and biological activity of a series of triclosan‐based inhibitors is reported, including their promising efficacy against INH‐resistant strains of M. tuberculosis.

     

掺杂石墨烯气体扩散电极电芬顿氧化降解三氯生废水模拟

为了解决水中个人护理品难以处理的问题,以具有优良氧还原催化活性的掺杂石墨烯气体扩散电极（rGO/C-PTFE GDE）为阴极,构建了均相电芬顿氧化体系,探讨了石墨烯掺杂量、电流密度、电解质浓度等因素对rGO/C-PTFE GDE原位生成H2O2的产率和电流效率的影响,确定了电生成H2O2的最优化条件,即石墨烯与片状石墨的质量比为1∶8,电流强度为2.0 mA/cm2,电解液浓度为0.05mol/L。该条件下经180 min电解H2O2积累浓度可达到187.1mg/L。以rGO/C-PTFE GDE为阴极构建了均相电芬顿氧化体系,并应用于含三氯生模拟废水的氧化降解,研究了电解液pH值和外加Fe2＋浓度对三氯生去除效果的影响。结果表明：对于初始浓度为45 mg/L的三氯生,在pH值为3.0,外加Fe2＋浓度0.75 mmol/L的条件下,经过180 min均相电芬顿氧化的处理,73.9%的三氯生可被氧化降解。