纳米银的单颗粒-电感耦合等离子质谱法表征及其测定

建立单颗粒-电感耦合等离子体质谱法( SP-ICP-MS)测定稀溶液中纳米银颗粒粒度分布及纳米银颗粒数量浓度的方法。当停留时间为3 ms时,两个或多个纳米银颗粒同时进入检测器的可能性降至最低。采用5倍标准偏差迭代算法(5σ)区分纳米银颗粒信号和背景信号。采用SP-ICP-MS法测定3种商品级纳米银颗粒(30,50和100 nm)粒度分布和纳米颗粒浓度。结果表明：SP-ICP-MS法测定纳米银颗粒结果与纳米银的TEM值相近,可采用SP-ICP-MS法表征纳米银颗粒。本方法测定稀溶液中纳米银颗粒粒度检出限为25 nm,纳米银颗粒浓度检出限约为8×104个/L。将纳米银颗粒加入到自来水样品中并进行测定,获得相近的纳米银粒度分布及纳米颗粒浓度。本方法简单、快捷、灵敏度高,可为研究水环境中纳米银的风险评估提供可靠分析方法,并为饮用水中纳米银的监测提供分析技术。     

紫外-可见光谱法分析难溶性黄药重金属配合物

提出可用于难溶性黄药重金属配合物检测的紫外光谱方法。实验首先考察了在黄药溶液中加入不同重金属离子后紫外-可见光谱的变化,发现Pb2+、Cu2+会与黄药生成难溶性配合物,而Fe2+,Zn2+,Mn2+对黄药溶液的紫外吸收影响很小。接下来实验比较了不同孔径的滤膜对难溶性配合物的去除效果,发现采用0.22 μm滤膜可以有效的将黄原酸铜或黄原酸铅与滤液分离。进一步的,实验研究了硫化钠与难溶性配合物反应的情况,结果表明S2-可以定量的将配合物中的黄原酸根置换到溶液中。研究得出可以通过加入硫化钠后滤液中黄药浓度的上升值得到原水样中难溶性黄药重金属配合物的含量。最后研究将该方法应用于郴州三十六湾三家铅锌选矿厂废水的分析中,其结果验证了该方法的可行性。     

固相微萃取在水样污染物检测中的应用

固相微萃取是一种具有高灵敏度、回收率和重复性等优点的前处理技术,广泛应用于水中痕量污染物的处理,本文从固相微萃取装置、基本原理及其在水样污染物检测的中应用展开介绍,并以固相微萃取作为主题检索词,利用ISI Web of Knowledge中Web of Science引文数据库,对1998年到2012年间的相关文献进行计量分析。结果表明,固相微萃取主要应用于水样前处理,杀虫剂是主要的富集对象,气相、液相色谱以及质谱是常使用的检测器。     

超声辅助提取-固相萃取-气相色谱-质谱法测定污泥中12种多环芳烃

污泥样品(约1g)经30mL的体积比为1∶1的乙酸乙酯和丙酮的混合液超声提取1.0h。离心后,取上清液,用硅固相萃取柱进行净化,采用气相色谱-质谱法测定净化液中12种多环芳烃的含量。在气相色谱分离中采用HP-5MS石英毛细管色谱柱,在质谱分析中采用选择离子监测模式。12种PAHs的质量分数均在5~500μg·kg^-1内与其对应的峰面积呈线性关系,检出限为2.29~14.50μg·kg^-1。以空白污泥样品为基体进行加标回收试验,所得回收率为54.9%~108%,测定值的相对标准偏差(n=7)为0.10%~5.4%。     

高分子在固液界面吸附构象的研究方法及手段

高分子在固液界面的构象表征对其功能实现及实际应用具有重要意义,是高分子研究领域的热点之一.由于高分子吸附构象的复杂性及其影响因素的多样性,选择合适的方法及手段成为表征的关键.本文简单介绍了影响高分子构象的一些因素,并从仪器分析的角度出发,根据研究目的综述了高分子与固体表面的键合方式、在固液界面的吸附方式、吸附行为及吸附层微观结构的研究方法和手段.     

Synthesis and Structural Characterization of N,N-disubstituted Acylguanidines

A series of five N,N-disubstituted acylguanidines R~1C(O)N=C[N(H)R~2]NR_2~3(R~1=Mes or Ph; R~2=Ar??or Ar?; R~3=Cy, Bn, iPr, or Et)(Mes=2,4,6-Me_3C_6H_2, Ar??=2,6-iPr_2C_6H_3, Ar?=2,6-Me_2C_6H_3) was synthesized from the reactions of parent acylthioureas with respective secondary amines. According to structutral characterization by single-crystal X-ray diffraction, the rough reduction of the steric hindrance of R substitutents of R~1 C(O)N=C[N(H)R~2]NR_2~3(also abbreviated as R~1-R~2-R~3 for comparison purposes) led to the slight enlongation of N(1)–C(1) bond lengthes and small decrease of N(1)–C(1)–N(3) bond angles from Mes–Ar??–Cy(1) to Ph–Ar??–Bn(2), Ph–Ar??–iPr(3) and Ph–Ar?–Cy(4). At the same time, the N(1)–H(1)···O(1) intramolecular hydrogen bonds were observed in these cases. When R~3=Et, an interesting compound Ph-Ar?-Et(5) was obtained with the formation of intermolecular hydrogen bonds instead. 1 belongs to the monoclinic system, space group P2_(1/n) with a=9.6488(3), b=28.5318(8), c=11.9155(3) ?, b=91.439(2)o, V=3279.27(16) ?~3, and Z=4. 2 belongs to the triclinic system, space group P1 with a=9.6759(7), b=10.8613(8), c=15.7642(12) ?, a=70.429(3), b=79.257(4), g=69.052(4)o, V=1453.63(19) ?~3 and Z=2. 3 belongs to the monoclinic system, space group P2_(1/c) with a=11.1393(4), b=13.0643(4), c=17.6600(6) ?, b=101.866(2)o, V=2515.09(15) ?~3 and Z=4. 4 belongs to the monoclinic system, space group C2/c with a=17.8466(3), b=13.6126(2), c=21.6710(4) ?, b=90.7310(10)o, V=4992.72(14) ?~3 and Z=8. 5 is of orthorhombic system, space group P2_12_12_1 with a=10.5555(2), b=11.8913(2), c=14.9558(4) ?, V=1877.23(5) ?~3 and Z=4.     

Synthesis and Characterization of Aryl Acylguanidines and Their Copper(Ⅱ) Complexes

A series of eight N-mono-substituted aryl acylguanidines L~(1～8) were synthesized from the reactions of their parent acylthioureas and respective primary amines, including five R~1C(O)N=C(NHR~2)_2 with balanced arms(denoted as R~1–R~2–R~2: Ph–Ar'–Ar', L~1(1); Ph–Ar'–Ar', L~2(2); 1-Naph–Ar'–Ar', L~3(3); 1-Naph–Ar'–Ar', L~4(4); 2-Naph–Ar'–Ar', L`5(5); Ar' = 2,6-Me_2C_6H_3, Ar' = 2,6-iPr_2C_6H_3) and three R~1C(O)N=C(NHR~2)NHR~3 with unbalanced arms(denoted as R~1–R~2–R~3: Ph–Ar'–Ph, L~6(6); Ph–Ar' –Ph, L~7(7); Ph–Ar' –Ar', L~8(8)). Treatment of L~(1～5)(1～5) with copper acetate in a molar ratio of 2:1 in dichloromethane led to the formation of homoleptic Cu(Ⅱ) complexes trans-L_2~(n')Cu(9～13), in which the Cu(Ⅱ) center was stabilized by deprotonated ligands Ln'(n = 1～5) in the O,N-bidentate mode. When similar reactions of L~6(Ph–Ar'–Ph)(6) and L~7(Ph–Ar'–Ph)(7) that contain unbalanced arms were investigated, the Cu(Ⅱ) products trans-L_2~(6')Cu(14) and trans-L_2~(7')Cu(15) were formed by deprotonating the bulky amine groups in Ln(-NHAr' for L~6 and-NHAr' for L~7) rather than the-NHPh group. In sharp contrast, trans-L_2~(8')Cu(16) was obtained from two-arm unbalanced L~8(Ph–Ar'–Ar')(8) not by deprotonating the more bulky-NHAr' group but the relatively less bulky-NHAr' group. In a further exploration, the reaction of 1:1 mixed ligands Ln and Lm with copper acetate was found to give only homoleptic Cu(Ⅱ) complex L_2~(n')Cu instead of the heteroleptic one L~(n')CuL~(m'). The in vitro antibacterial activity of L~n was evaluated against S. aureus, E. coli and C. albicans by determining the minimum inhibitory concentrations(MICs) using Kirby-Bauer test.     

高分子与表面活性剂在水相中的相互作用

按照组分荷电属性的不同,高分子/表面活性剂体系可大致划分为三种:中性高分子/离子表面活性剂体系、带电高分子/离子表面活性剂体系、高分子/非离子表面活性剂体系。本文对这三种体系在水相中的高分子/表面活性剂相互作用研究进行综述。在大多数情况下,水相中高分子与表面活性剂共存时都能发生相互作用并形成复合物,其驱动力主要包括疏水作用、静电作用和氢键作用。根据高分子与表面活性剂的荷电情况及结构性质(如疏水链长度)的不同,上述驱动力可以单独或组合作用。此外,温度、pH值、电解质等外界因素对复合物形成过程及结构也具有不同程度的影响。     

固相微萃取技术在水样污染物检测中的应用

固相微萃取是一种具有高灵敏度、回收率和重复性等优点的前处理技术,广泛应用于水中痕量污染物的处理。本文从固相微萃取装置、基本原理及其在水样污染物检测的中应用展开介绍,并以固相微萃取作为主题检索词,利用ISI Web of Knowledge中Web of Science引文数据库,对1998年到2012年间的相关文献进行计量分析。检索分析结果表明,固相微萃取主要应用于水样前处理,杀虫剂和多环芳香烃是主要的富集对象,气相、液相色谱及质谱是常使用的检测仪器。