Synthesis, crystal structure and electrochemical properties of [Co(phen)3] · (H3btec) · (H2btec)0.5 · DMF · 6H2O

A new complex [Co(phen)₃] · (H₃btec) · (H₂btec)_0.5 · DMF · 6H₂O (1) (H₄btec = 1,2,4,5-Benzenetetracarboxylic acid, phen = 1,10-phenanthroline, DMF = dimethylformamide) was synthesized by the reaction of pyromellitic dianhydride, phen · H₂O and CoSO₄ · 7H₂O. Complex 1 crystallizes in the triclinic system, space group P-1 with a = 11.8123(14) ?, b = 13.0356(16) ?, c = 17.575(2) ?, ?? = 91.461(2)°, ?? = 101.347(2)°, ?? = 99.830(2)°, FW = 1159.94, Z = 2, V = 2609.5(5) ?³. X-ray crystal structural determination indicates that the Co(II) ion is octahedral coordinated by six nitrogen atoms of three phenanthroline ligands. The [Co(phen)₃]²⁺ cation engages its phen ligands in ??-?? interactions with H₂btec anion. Extensive hydrogen bonding interactions occur between water molecules, DMF, H₃btec and H₂btec anions. The highly-crystalline compounds 1, which are insoluble in water as well as common organic solvents, have been characterized in the solid-state by elemental analysis, thermogravimetric analysis and IR spectra. Moreover, the study of the electrochemistry of complex 1 was carried out by using cyclic voltammetry. It revealed that the Co(II) complex exhibits a quasi-reversible one-electron redox process.     

草酸钴原位催化高氯酸铵热分解的DSC／TG-MS研究

采用差示扫描量热/热分析-质谱(DSC/TG-MS)联用技术研究了草酸钴对高氯酸铵的原位催化. 结果表明,草酸钴原位分解生成的钴氧化物对高氯酸铵有较强的催化作用,添加2%的草酸钴使高氯酸铵的分解温度降低104 ℃, 分解放热量从655 J/g增大到 1 469 J/g. 分解的气相产物主要有H2O, NH3,O2,HCl,Cl2,NO,N2O和NO2. 由于氧在新生态的纳米钴氧化物表面形成过氧化活性离子(O-2), 使氨氧化在钴氧化物的过氧化表面活性中心进行,加速了高氯酸铵的热分解,使其表观放热量大幅度增加.     

茶叶中有机氯和拟除虫菊酯多种农药残留同时分析的样品前处理研究

建立了茶叶中同时分析12种有机氯和拟除虫菊酯类农药残留的样品提取和固相萃取(SPE)前处理方法.试样在超声条件下用正己烷提取后用自制弗罗里圭(florisil)/石墨化碳复合固相萃取小柱净化,然后采用气相色谱-电子捕获检测器(GC-ECD)测定.研究结果表明,当茶叶中农药加标在4.93～201.00 ng/g范围内时,添加回收率为68.9%～112.2%,相对标准偏差为2.43%～15.8%,方法的检出限范围在2.52～10.59 ng/g.     

ICP-MS测定化肥中有害元素Cr、Cd、As、Pb、Hg的新方法

采用电感耦合等离子体质谱法测定化肥中微量Cr、Cd、As、Pb、Hg元素.样品经微波消解和敞开酸溶,滴加5 ～8滴2%高锰酸钾氧化,低温水浴加热蒸至近干,加甲醇2 mL溶剂化,用水定容至100 mL,进行测定.方法标准加入回收率为67% ～115%,RSD小于15%,误差完全符合GB18877-2002的规定要求,方法简便快速.     

Ti基电极上光化学沉积Hg用于吸附溶出伏安法测定磺胺嘧啶

该研究发现采用紫外光照射钛电极表面氧化钛层能够光催化还原Hg2+生成Hg微粒,在Ti基电极上光化学沉积Hg比电化学沉积Hg对磺胺嘧啶具有更强的吸附作用,基于光化学沉积Hg/Ti电极建立了一种吸附溶出伏安法测定磺胺嘧啶的方法.详细考察了溶液pH值、吸附富集时间、溶出起始电位、扫描速率等对测定的影响.结果表明,在pH 2.0 的B-R缓冲溶液中,磺胺嘧啶在0.48 V左右处产生1个灵敏的氧化峰,其峰电流与磺胺嘧啶的浓度在1.2×10-8～1×10-6 mol/L范围内呈良好的线性关系(r=0.997 2),检出限达4.35 nmol/L.     

分散液相微萃取-气相色谱联用测定葡萄中百菌清、克菌丹和灭菌丹残留

采用分散液相微萃取与气相色谱-电子捕获检测联用技术建立了测定葡萄样品中百菌清、克菌丹和灭菌丹农药残留的新方法.对影响萃取和富集效率的因素进行了优化.萃取条件选定为在10 mL带塞离心试管中加入 5.0 mL葡萄样品溶液,并加入1.0 mL丙酮(分散剂),振荡摇匀后以5000 r/min离心5 min,然后将上层清液转移至另一离心试管中,加10.0 μL氯苯(萃取剂),分散混匀后再以5000 r/min离心5 min,萃取剂氯苯相沉积到试管底部,吸取1.0 μL萃取相直接进样分析.在优化的实验条件下,3种杀菌剂的富集倍数可达788～876倍;检出限在6.0～8.0 μg/kg(S/N=3∶ 1)范围内.以α-六六六为内标,测定3种杀菌剂的线性范围为10～150 μg/kg,线性相关系数在0.9990～0.9995范围内.本方法已成功应用于葡萄样品中百菌清、克菌丹和灭菌丹残留的测定,平均加标回收率在92.3%～106.1%范围内;相对标准偏差在4.5%～7.2%之间,结果令人满意.     

加速溶剂萃取-固相萃取-硅胶吸附色谱-电喷雾质谱法测定纺织品中的烷基酚聚氧乙烯醚

建立了测定纺织品中壬基酚聚氧乙烯醚和辛基酚聚氧乙烯醚的硅胶吸附色谱-电喷雾质谱分析方法.不同类型的纺织品样品采用加速溶剂萃取法,以无水乙醇为提取溶剂,在10.3 MPa和100 ℃下静态循环提取2次,提取液经Sep-Pak Carbon/NH2石墨化碳黑/氨基复合型固相萃取柱净化,以Waters Spherisorb S3W(150 mm×2.0 mm, 3 μm)色谱柱为分离柱,乙腈-水体系为流动相梯度洗脱,在电喷雾质谱正离子模式下进行定性及定量分析.壬基酚聚氧乙烯醚的方法检出限为10～40 μg/kg,在1～20 mg/kg的3个添加水平范围内的平均回收率为81.4%～95.9%,相对标准偏差均小于12.5%.辛基酚聚氧乙烯醚的方法检出限为10～30 μg/kg,在1～20 mg/kg的3个添加水平范围内的平均回收率为80.2%～96.8%, 相对标准偏差均小于13.0%.本方法准确、简便、快速,可用于纺织品的实际检验工作.     

高效液相色谱-电喷雾串联质谱法快速测定纺织品中苯氧羧酸类除草剂残留量

建立了纺织品中7种苯氧羧酸类除草剂的高效液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)快速检测方法.样品经甲酸酸化的丙酮溶液超声提取两次,无需其它净化过程.液相色谱使用C18反相色谱柱,流动相为醋酸铵水溶液和甲醇,在梯度条件下分析.在选择反应检测(SRM)负离子模式下进行质谱信号采集,采用两对同位素离子对进行定性和定量分析.选取3种有代表性的纺织品进行方法检出限(LOD)、定量限(LOQ)、线性、回收率和精密度的验证.方法的LOQ为 0.9～2.4 μg/kg; 回收率为85%～106%; 相对标准偏差为2%～11%.本方法简便、有效、可靠、灵敏,能够满足国际生态纺织品标准(Oeko-Tex Standard 100)的限量要求,适用于纺织品中苯氧羧酸类除草剂的日常检测及确证.     

DBAH-Tf靶向药物及其对乳腺癌细胞的杀伤作用分析

以转铁蛋白(Tf)为靶向载体,与双氢青蒿素(DHA)化学偶联制备一种新的双氢青蒿素衍生物-转铁蛋白靶向药物.以DHA为原料先合成了12β-对甲酰肼苯基双氢青蒿素(DBAH),并采用紫外、红外、核磁共振及电化学等手段对目标产物的结构进行了表征.利用高碘酸钠氧化Tf的C端的N-糖链上的邻位羟基,其氧化产物和DBAH通过希夫碱偶联合成了DBAH-Tf靶向药物,采用紫外吸收光谱法和电化学方法进行表征.四甲基氮唑蓝法(MTT)分析了DBAH-Tf及DHA对人乳腺癌细胞(MCF-7)和正常乳腺细胞的体外杀伤作用, 结果表明,DBAH-Tf对MCF-7的杀伤作用是正常乳腺癌细胞的286倍,体现出良好的靶向性.     

Preparation of PVDF porous membranes by using PVDF-g-PVP powder as an additive and their antifouling property

The hydrophilic PVDF-g-PVP powder was used as additive to prepare a series of PVDF/PVDF-g-PVP blend porous membranes via an immersion precipitation phase inversion process. FTIR-ATR measurements confirmed that the hydrophilic PVP preferentially segregated to the interface between membrane and coagulant. SEM images showed that there was no big change in the membrane cross-section with the amount of PVDF-g-PVP increased. However, the membrane surface roughness increased with the amount of PVDF-g-PVP increased according to AFM data. The mean pore size of membranes reached max when the amount of PVDF-g-PVP was 10 wt%. The water contact angle and filtration experiments revealed that the surface enrichment of PVP endowed the membranes with significantly enhanced surface hydrophilicity and protein-adsorption resistance. The flux recovery of the porous membranes was increased from 37.50% to 77.23% with the amount of PVDF-g-PVP increased from 0 to 50 wt%, also indicating that the antifouling property of the porous membranes was improved.