多批次肝衰竭患者呼出气体的电喷雾萃取电离质谱检测及代谢组学数据分析

采用高分辨电喷雾萃取电离质谱(EESI-MS)技术对肝衰竭患者和健康志愿者呼出气体样本进行快速检测, 结合多块偏最小二乘分析(MB-PLS)方法, 对多批次获取的呼出气体代谢数据进行统计建模分析, 并与传统的PLS方法进行比较. 结果表明, MB-PLS方法能有效消除批次差异对统计建模的影响. 此外, 利用MB-PLS模型变量VIP值对变量进行筛选, 可降低数据的冗余, 消除无关变量对模型的影响, 从而有效提高了模型的性能.     

Corrosion inhibition and performance evaluation on 2,5‐diaryl‐1,3,4‐thiadiazole and its derivatives

Using electrochemical impedance spectroscopy (EIS) and scanning electronic microscopy (SEM), this paper evaluated the inhibition effect of four 2,5‐diaryl‐1,3,4‐thiadiazole and its derivatives named 2,5‐diphenly‐1,3,4‐thiadiazole (DPTD), 2,5‐di(2‐hydroxyphenly)‐1,3,4‐thiadiazole (2‐DHPTD), 2,5‐di(3‐hydroxyphenly)‐1,3,4‐thiadiazole (3‐DHPTD), and 2,5‐di(4‐hydroxyphenly)‐1,3,4‐thiadiazole (4‐DHPTD) on silver strip corrosion in 50 mg/l sulfur–ethanol solution under room temperature. The experiments indicated that the inhibition efficiency increased with increasing inhibitor concentrations, and the increasing order was (4‐DHPDT) > (3‐DHPDT) > (2‐DHPDT) > (DPDT). Quantum chemical calculation was applied to correlate inhibition performances with their electronic structural parameters of thiadiazole derivatives. Molecular dynamics simulations (DFT) were used to optimize the equilibrium configurations of the inhibitor molecules on the silver surface and to investigate the molecular structure effect on the corrosion inhibition efficiency. The efficiency order of the investigated inhibitors, which was obtained by experimental results, was verified by theoretical calculations. Contact angle (CA) analysis was also carried out, and finally confirmed the existence of the adsorbed film which prevailed in addition of thiadiazole derivatives. CA analysis indicated that the film of n‐DHPTD (n = 2,3,4) was hydrophilic, owing to two hydroxyl groups in their molecular. The adsorption of these compounds onto silver strip from 50 mg/l S‐ethanol system obeys Langmuir adsorption isotherm, and it belongs to mixed‐type adsorption mainly dominated by chemisorption. Copyright © 2016 John Wiley & Sons, Ltd.     

双-(二烷硫基四硫富瓦烯二硫)金属配合物的合成及性质研究

合成了三种未见文献报道的双-(二烷硫基四硫富瓦烯二硫)金属配合物和三种新的四硫富瓦烯(TTF)桥联的双金属配合物,测定了它们的导电率,讨论了含Ni配合物的电导率优于含Cu,Hg配合物的原因。     

液相色谱-四极杆飞行时间质谱法快速测定草莓中6种植物生长调节剂的残留量

建立了高效液相色谱-四极杆飞行时间串联质谱(HPLC-Q TOF MS)快速检测草莓中2,4-滴、对氯苯氧乙酸、3-吲哚丁酸、氯吡脲、脱落酸、玉米素6种植物生长调节剂的分析方法。样品采用QuEChERS方法(Quick, Easy, Cheap, Effective, Rugged and Safe method)进行前处理(乙腈提取,C18吸附剂净化),采用Eclipse XDB-C8色谱柱(150 mm×4.6 mm, 5 μm),以乙腈-5 mmol/L乙酸铵-0.1%(v/v)甲酸水溶液为流动相,梯度洗脱,Q TOF MS电喷雾负离子模式分析检测。在全扫描采集模式下,以准分子离子峰的峰面积定量,以化合物的精确质量数定性。在Target MS/MS采集模式下,通过碎片离子的精确质量数进一步确证化合物。各化合物在0.005～1.0 mg/L范围内均呈现良好的线性关系,相关系数均大于0.99。6种化合物的检出限为1～5 μg/kg,添加回收率为87%～107%,相对标准偏差(RSD)均小于10%(n=6)。本方法简便快捷,选择性好,灵敏度高,可满足国内外现行法规的限量要求。     

油溶性缓蚀剂ω,ω’-双(1-辛基苯并咪唑-2-基)烷烃的合成及缓蚀性能研究

合成了系列ω,ω’-双(1-辛基苯并咪唑-2-基)烷烃油溶性缓蚀剂,并通过红外、质谱等进行结构表征。通过恒电位极化曲线,考察了此类缓蚀剂在2×10-4mol/L H2S-乙醇溶液中对铜电极极化曲线的影响。结果表明,此系列油溶性缓蚀剂对铜电极具有明显的缓蚀作用,且对金属铜的缓蚀效率高,作为润滑油添加剂具有很好的应用前景。     

气液色谱法研究双—(O,O''''—二正辛基二硫代磷酸酯)合镍(Ⅱ)与五员杂环化合物加合反应的热力学性质

气液色谱法是研究酸碱相互作用热力学性质的有效方法之一,适合于气液表面化学反应的研究,可以得到一些用其他方法难以获得的热力学参数,丰富了表面化学领域的研究,具有重要的理论意义和应用价值。文献[1—4]利用气液色谱法测量了Ni[THDD]_2、Ni[(C_8H_(17)O)_2PS_2]_2与含氮、含氧有机碱加合反应的平衡常数、标准焓变和标准熵变值。作为酸碱加合反应研究的一部份,本文测定了Ni[C_8H_(17)O)_2PS_2]_2与五员杂环化合物呋喃、噻吩和吡咯反应的热力学参数。     

On-line sample-pre-treatment schemes for trace-level determinations of metals by coupling flow injection or sequential injection with ICP-MS

Within the last decade, the first generation of flow injection (FI) has been supplemented by sequential injection (SI), also termed the second generation, and, recently, by the third generation, i.e., SI-Lab-on-Valve (SI-LOV). As apparent from the literature, FI and/or SI have become dominant as substitutes for labor-intensive, manual, sample-pre-treatment and/or solution-handling procedures prior to analyte detection by inductively coupled plasma mass spectrometry (ICP-MS). The present review presents and discusses the progress of the state of the art in implementing miniaturized FI/SI systems for on-line matrix separation and pre-concentration of trace levels of metals with detection by ICP-MS. It highlights some of the frequently applied on-line, sample-pre-treatment schemes, including solid phase extraction (SPE), on-wall molecular sorption and precipitate/(co)-precipitate retention using a polytetrafluoroethylene (PTFE) knotted reactor (KR), solvent extraction-back extraction and hydride/vapor generation. It also addresses a novel, robust approach, whereby the protocol of SI-LOV-bead injection (BI) on-line separation and pre-concentration of ultra-trace levels of metals by a renewable microcolumn is interfaced to ICP-MS, as conducted in the present authors' group. It discusses the future outlook in this field.     

固相萃取高效液相色谱-质谱法测定动物组织中硝基呋喃代谢产物

研究了对动物组织中4种硝基呋喃类代谢产物AOZ、AMOZ、SEM和AHD的自动固相萃取HPLC-MS分析方法，分别以2-氯苯甲醛和2-硝基苯甲醛作为衍生化试剂，分别用AMOZ-d5、AOZ-d4作内标，用ENSPE柱进行提取，以乙腈-0．1％甲酸为流动相，采用梯度洗脱，可在15min内将4种代谢产物完全分离并进行测定。回收率为85％-90％；检出限可达0．5μg／kg。采用两种衍生化方法可获得较多的定性确证信息。采用本方法研究了硝基呋喃在鸡饲养过程中的残留规律。     

液相色谱紫外法测定鸡肉中三种硝基咪唑残留量

建立了测定鸡肉中二甲硝咪唑、罗硝唑、甲硝唑残留量的方法。以二氯甲烷提取,硅胶固相萃取净化,液相色谱紫外法检测。样品添加１０μｇ／ｋｇ,５０μｇ／ｋｇ,平均回收率为７８％～９１％,相对标准偏差为６．４％～１０．１％。     

直接由SiO_2低温合成含硅聚氨酯及其结构表征

有机硅材料是一类应用非常广泛的材料,但这些产品所用基本原料几乎都来源于石英沙(SiO2)的高温碳热还原[1],这个方法已大规模的工业化,但它的高能耗、高腐蚀成为人们越来越关注的问题.1991年美国Laine[2]直接以SiO2为原料成功地制备了五配位、六配位有机硅化合物,并进一步合成了导电材料和高性能陶瓷[3～7].我们实验室自1995年以来,在Laine的基础上,发现如果以沙子为原料,则产率非常低,即使在超声波作用下,反应一周合成的五配位硅化合物其产率不足10%,这可能是由于沙子的晶型非常完美,在200℃下很难打破Si-O键生成配位硅,如果以无定型SiO2为原料(如白碳黑,稻壳灰等),合成的五配位硅其产率几乎为100%,而且反应时间缩短为4h.然后以高活性的五配位硅为原料制备了一系列的含硅有机物,如与环氯丙烷反应[8],不仅消除了五配位硅化合物的水解可逆性反应,中和了它的强碱性,而且把环氧基团接到了配位硅化合物上,生成了一种非常类似于液态环氧树脂的淡黄色的粘稠状液体.我们按Laine的路线,向含硅聚合物方向发展[9].本文合成的双羟基四配位硅单体是五配位硅钾化合物向含硅聚合物转化的关键,由于其结构带有两个活泼羟基,可以和二元酰氯、二元羧酸、二异氰酸酯、导氰酸酯基封端的聚醚或异氰酸酯基封端的聚酯进行缩聚反应,合成主连含硅的聚合物.