The First Hybrid Wells-Dawson-type Polytungstate Monosupported by Cd-coordination Complex via Di-bridging O-atom

Polyoxometalates(POMs) with Cd-coordination complexes acting as supporting units are rarely reported. The linkage of the supporting units with inorganic building block(polyanion) is generally established on terminal O-atoms, but scarcely via bridging O-atoms. By introducing liquid small organic molecule(pyridine, C5NH5) as assistant "structure-directing agent", we obtained a novel organic-inorganic hybrid polytungstate,(Hpy)4[Cd(phen)2(P2W18O62)]·nH2O(1, n ≈ 3, py = pyridine, phen = 1,10-phenanthroline), under hydrothermal conditions. The single-crystal X-ray diffraction analysis shows that 1 is the first compound containing an asymmetric heteropolyanion, [Cd(phen)2(P2W18O62)]4–, a Wells-Dawson-type polyanion monosupported by Cd-coordination complex via di-bridging O-atoms.     

竹炭固相萃取-恒能量同步荧光法测定河水中多环芳烃

建立了竹炭固相萃取-恒能量同步荧光法检测河水中多环芳烃(PAHs)的方法。优化了实验条件。选定正己烷为洗脱溶剂,洗脱溶剂体积为15mL,上样速率为5mL/min,上样体积为500mL。采用恒能量同步荧光法对流出液中PAHs进行测定,其相关系数r≥0.9976,检出限在0.025～1.5ng/mL之间,相对标准偏差为0.72%～1.68%。该法用于龙岩市省控断面九龙江河水中PAHs的测定,水样的加标回收率为76.8%～104.4%。     

在亚硝酸盐存在下钴(Ⅱ)-中性红络合物的极谱催化波的性质

在0.2 mol.L-1的氨水-NH4Cl(pH 9.5)缓冲溶液中,1.0 mol.L-1NaNO2存在下,钴(Ⅱ)-中性红(NR)络合物于-1.19 V(vs.SCE)处产生灵敏的极谱波,二阶导数波峰电流与钴浓度在2.0×10-8~5.0×10-6mol.L-1范围内呈线性关系,检出限为1.0×10-8mol.L-1。研究了钴(Ⅱ)-中性红(NR)络合物的电极反应机理,证明了该波为不可逆极谱催化波,测得电活性络合物组成为钴(Ⅱ)∶(NR)=1∶1。电活性络合物的中心离子钴(Ⅱ)还原,电子转移数n=2。该方法用于维生素B12注射液和天然水中痕量钴的测定,测得分析结果的RSD(n=6)值均小于0.7%,回收率在98%至101%之间。