首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 203 毫秒
1.
本文报道了一种以牛磺酸双核铜络合物为中性载体的硫氰酸根PVC膜电极。该电极对硫氰酸根有良好的电位响应并呈现出anti-Hofmeister行为,其选择性顺序SCN->I->ClO4->Sal->NO3-> NO2-> Br- > Cl- > SO3-> SO4 2-。在20℃ pH 5.0的磷酸缓冲溶液中,其线性范围为1.0´10 -1~ 1.0´10-6mol×L-1,检测线为8.0×10 -7mol•L-1,斜率为 -56.5 mV/pcSCN-。紫外、红外和交流阻抗研究表明电极的高选择性与载体的立体结构和分析物与中心金属离子的作用相关。将该电极用于废水和人体尿液中硫氰酸根的测定,获得了较满意的结果。  相似文献   

2.
为了探究胡蜂酒中无机阴离子的含量和组成,利用离子色谱法测定胡蜂酒中5种阴离子(F-、Cl-、Br-、NO3-、PO43-)含量,建立了一种同时测定胡蜂酒中5种无机阴离子的方法。并测定不同产区胡蜂酒阴离子含量,分析不同产区间胡蜂酒阴离子含量之间的差异,以期为胡蜂酒的评价提供新思路。结果表明,5种无机阴离子标准曲线相关系数良好,相关系数范围在0.9980≤ r ≤ 0.9999之间,检出限在0.024~4.33 mg.L-1之间, 5种阴离子的回收率在84.13~100.19%之间,RSD为 0.17~1.24 %,所建立的分析方法准确、可靠,能满足胡蜂酒中阴离子分析的要求。不同产区胡蜂酒中阴离子含量存在差异,5种阴离子平均含量高低次序为PO43-(2666.825 mg/L)、Cl-(77.550 mg/L)、NO3-(9.408 mg/L)、F-(6.220mg/L)、Br-(0.760 mg/L)。16个不同产区胡蜂浸泡酒中F-变异系数最大,说明不同产区中F-含量波动较大。Cl-、PO43-变异系数最小,说明不同产区胡蜂之间含量较稳定。  相似文献   

3.
采用溶胶-凝胶法和水热法(HTM)合成了Fe3O4@SiO2@TiO2-Co/rGO复合纳米粒子(磁性光催化剂),通过X射线衍射、扫描电子显微镜及其能量分散光谱和UV-vis漫反射光谱对产物进行了表征分析.研究了Co掺杂量、溶液pH值、亚甲基蓝(MB)溶液初始浓度以及干扰离子(例如Cl-、SO42-、CO32-)等因素对MB降解的影响,并对磁性光催化剂的可重复使用性进行了分析.正常实验条件下(pH=7,[MB]=10 mg/L,磁性光催化剂用量=0.1 g/50 mL),150 min内MB最大去除率达到98.24%.干扰离子影响MB降解次序为CO32- < Cl- < SO42-,磁性光催化剂重复使用7次MB光降解率仅下降7.07%,新型磁性光催化剂具有良好的MB降解性能和较高的重复使用性能.  相似文献   

4.
采用一步共缩合-水热法合成酸性载体SO42-/ZrO2-SiO2,化学法接枝酸性离子液体磺酸功能化咪唑硫酸氢盐([Ps-im]HSO4),构筑拥有Brönsted与Lewis双酸位的离子液体固载型催化剂SO42-/ZrO2-SiO2-IL。采用X射线衍射、傅里叶红外、N2吸附-脱附、X射线光电子能谱、热重以及透射电镜对催化剂的结构进行表征,结果表明:锆原子和酸性结构SO42-被成功引入纯硅材料,所合成的载体具有一定酸性;离子液体成功固载于酸性介孔材料SO42-/ZrO2-SiO2,且固载后的催化剂保持其介孔结构。以大豆油和甲醇的酯交换反应为探针,考察了SO42-/ZrO2-SiO2-IL催化剂的催化性能。在反应温度为150℃、反应时间为4 h、催化剂量5%(w/w)、醇油物质的量之比为24:1的反应条件下,生物柴油的收率超过92%,且回收利用5次后,生物柴油的收率仍达86%。  相似文献   

5.
设计合成了一种基于偶氮苯基团的简单而高效的比色探针L1,并利用紫外-可见吸收光谱考察其对阴离子(F-, Cl-, Br-, I-, AcO-, H2PO4-, HSO4-, ClO4-和CN-)的识别性能。结果表明:探针L1在DMSO/H2O(5:5, V/V)的含水体系中,可以实现对CN-单一选择性识别;且加入CN-时,溶液颜色立刻由无色变为红色,而加入其它阴离子则无变化,说明该探针能够实现对CN-的裸眼识别。另外,该探针对CN-的检测灵敏度较高,最低检测限达到了1.3 μmol·L-1。此外,我们制作了负载有探针分子L1的试纸条,能够更加方便快捷的检测CN-。  相似文献   

6.
通过电感耦合等离子体质谱法(ICP-MS)测定土壤中的碘。样品预处理采用艾斯卡试剂熔融、热水提取和阳离子树脂静态交换,试验加入了不同剂量的阳离子交换树脂在不同程度上降低了溶液中Na+ 和Zn2+等阳离子的盐效应干扰。研究了乙醇在ICP-MS中对碘元素的增强效应,用3%的氨水溶液清洗进样系统,有效减少的碘的记忆效应和清洗时间。该方法线性范围宽,方法灵敏度高,检出限低,试剂用量少,环境友好。对苏州及周边区域若干非污染土壤点位进行采样、制备和测试,碘平均含量为2.7μg.g-1;同步测试国家有证标准物质,精密度和准确度良好。  相似文献   

7.
Aldisin及其衍生物的合成和α-葡萄糖苷酶抑制活性研究   总被引:2,自引:0,他引:2  
以三氯氧磷为环化试剂, 回流状态下, N-(2-吡咯甲酰基)-β-丙氨酸经分子内酰化环化反应, 合成了吡咯[2,3-c]氮杂二酮稠环化合物Aldisin及其衍生物1-Methylaldisin和3-Bromoaldisin, 通过1H NMR, 13C NMR, IR, FABMS和元素分析对其结构进行了表征. 以X射线衍射法研究了3-Methylaldisin的晶体结构. 测定了三个化合物对α-葡萄糖苷酶的抑制作用.  相似文献   

8.
刘艳玲 《无机化学学报》2021,37(12):2244-2248
为实现次氯酸根的实时、快速、便捷检测,我们以2,7-二溴-9-芴酮为原料,通过两步常规反应,合成了一种新型的turn-on型ClO-荧光探针。在磷酸缓冲盐溶液(PBS)中,随着ClO-浓度的增大,探针在511 nm的发射峰逐渐增大,呈绿色荧光发射。探针与ClO-反应迅速,10 s内反应完成。此外,该探针对ClO-有较低的检出限,检出限为0.74 μmol·L-1。细胞实验表明探针可以在细胞水平检测内源性和外源性的ClO-。  相似文献   

9.
设计合成了3种乙二醛缩双芳氨基硫脲受体分子。利用紫外-可见吸收光谱及1H NMR考察了其与F-、Cl-、Br-、I-、CH3COO-、C3H7COO-、HSO4-、NO3-等阴离子的作用。结果表明,该类受体分子与阴离子形成氢键配合物。加入F-、CH3COO-、C3H7COO-时,溶液颜色立刻由无色转变为深黄色,而加入其它阴离子则无变化,从而实现对这3种阴离子的裸眼检测。通过计算可知,随着苯环上取代基的变化,此3种受体分子对F-和CH3COO-的识别作用呈现有规律的变化。即o-F取代基的受体分子对阴离子的识别作用大于其他2种受体分子,且主客体间形成1∶1的配合物。1H NMR滴定及质子溶剂效应进一步证明了受体分子与阴离子之间以氢键作用方式相结合。  相似文献   

10.
利用简便方法高效的合成了三种双缩氨基硫脲衍生物受体分子。利用紫外-可见吸收光谱及1H NMR考察了该三种受体分子的阴离子识别性能。结果表明,该类受体分子均对F-,CH3COO-和H2PO4-有较好的选择性识别作用,而对Cl-,Br-,I-,HSO4-和NO3-没有明显作用。当在此三种受体分子的DMSO溶液中加入F-,CH3COO-和H2PO4-时,可用肉眼观察到溶液颜色立刻由无色转变为深黄色,而加入其它阴离子则无变化,因而当溶液中存在其它卤素阴离子时可利用此类受体分子检测F-。通过计算可知,随着苯环上取代基的变化,此三种受体分子对F-,CH3COO-和H2PO4-的识别作用呈现有规律的变化。即对同种阴离子,其平衡常数为:受体1>受体3>受体2。且主客体间形成1:1的配合物。1H NMR 滴定及质子溶剂效应进一步证明了受体分子与阴离子之间以氢键作用方式相结合。  相似文献   

11.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

12.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

13.
Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.  相似文献   

14.
Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.  相似文献   

15.
Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, Mo, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

16.
针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。  相似文献   

17.
The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe2O3. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

18.
Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.  相似文献   

19.
20.
翟宗玺  刘树深  夏树屏 《化学学报》1990,48(10):946-950
用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号