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 78 毫秒
1.
测定N—亚硝基化合物的分光光度法   总被引:2,自引:0,他引:2  
沈彬  朱建华 《分析化学》1998,26(12):1478-1480
利用N-亚硝基化合物的化学去亚硝基反应,建立了一种间接测定N-亚硝基化合物的分光光度法。实验结果表明,N-二苯基亚硝胺在0.2 ̄9.0mg/L浓度内呈线性关系。该法应用于香烟烟丝及侧流烟雾萃取液的分析,4次测定RSD及回收率分别为1.86% ̄6.32%,86.2% ̄96.6%;3.01% ̄5.03%,101.1% ̄109.1%。  相似文献   

2.
反相高效液相色谱法测定碘   总被引:4,自引:0,他引:4  
李华斌  丁朝武 《分析化学》1998,26(2):203-206
建立了碘的反相高效液相色谱测定方法。色谱条件为:Shim-pack CLC-ODS柱;流动相为甲醇-水(20:80);流速为1mL/min;检测波长为290nm。本方法的线性范围为0.10 ̄10mg/L;相对标准偏差为1.1% ̄1.4%;加标回收率为97% ̄101%。所建立的方法已用于医用碘酒的测定。  相似文献   

3.
偏最小二乘催化极谱法同时测定铂,钯,铑   总被引:6,自引:0,他引:6  
应用M273A电化学系统中的线性扫描技术,确定了0.75mol/LH2SO4-1.5%NH4Cl-2.8mmol/L(CH2)6N4-0.0025%N2H4.H2SO4为偏最小二乘极谱法同时测定Pt、Pd、Rh的最佳极谱体系。Pt、Pd、Rh的线性范围为3.2mg/L、0-15.0mg/L和0-1.0mg/L。模拟样品及实际样品的回收率在90.3-107.7%之间。  相似文献   

4.
不完全抑制电导检测离子色谱法测定饮料中的苹果酸   总被引:2,自引:0,他引:2  
朱岩  徐素君  王素芬 《分析化学》1999,27(9):1050-1053
采用一种抑制型离子色谱检测技术--不完全抑制电导检测,以0.75mmol/LNa2SO4+NaOH(pH=11.5)为淋洗液对弱酸根离子如苹果酸、酒石酸等进行了测定,得到苹果酸、酒石酸的检测限分别为1.31mg/L、3.04mg/L;在200mg/L以下相关系数分别为0.9998、0.9999;;各离子峰高的相对标准偏差(RSD)分别为0.57%、1.60%。上率为97.7 ̄104%。常见的强酸离  相似文献   

5.
串联质谱法快速分析皮革中五氯酚残留   总被引:3,自引:1,他引:2  
建立了皮革样品中五氯酚的串联质谱分析方法,以m/z266为母离子,碰撞电压为0.8V,以子离子n/z230为定量离子,外标法定量。线性范围为0.1 ̄10.0mg/L,检出限为0.005mg/kg,回收率为85.4% ̄102.5%,相对标准偏差为2.55% ̄3.55%。方法具有快速、准确的特点。  相似文献   

6.
本文报导了以玻碳电极为基体的1:12硅钼杂多阴离子薄膜化学修铈电极的制备及其电化学特性。并应用于导数伏安法测定。在4.0×10 ̄(-3)m0l/L(NH_4)_6MO_7O_(24)-6.8×10 ̄(-2)mol/LNa_3Cit-0.48mol/LNHO_3体系中,硅浓度在8.3×10 ̄(-7)~1.7×10 ̄(-3)mol/L范围内与峰电流呈良好线性关系,检测限为8.0×10 ̄(-7)mol/L。对可溶性硅(以SiO_2计)为245.05mg/L的黑液,稀释10倍后,取2.00mL平行测定9次,RSD为0.58%,加标回收率在97.3%~104.4%间。  相似文献   

7.
碘的凝胶色谱测定方法   总被引:6,自引:1,他引:6  
丁朝武  李华斌 《分析化学》1997,25(5):586-589
建立了碘折凝胶色谱测定方法。色谱条件为:Shim-pack DIOL-150柱;流动相甲醇0.01mol/L H3PO4(10:90)流速为1.2mL/min;柱温为35℃,检测波长为224nm;线性范围是0.010-1.0mg/L,相关系数为0.9993,检测限为0.001mg/L,相对标准偏差为1.2%-4.6%;回收率为91%-98%。所建立的方法已用于食盐,尿,系带等样品的测试,均取得较好  相似文献   

8.
以酒石酸-乙二胺为淋洗液的单柱离子色谱法同时测定磷酸中痕量钠(Ⅰ)和铁(Ⅲ)。淋洗液最佳浓度为4.0mmol.L ̄(-1)、酒石酸/1.0m mol·L ̄(-1)乙二胺。最低检测限为Na ̄+0.05μg/mL、 Fe3+ 0.45μg/mL。电导检测灵敏度为2.0μg/cm。线性范围Na ̄+、Fe3+0.2~1.5×103μg/mL、2.5~1.0×103μg/mL。相对平均偏差Na ̄+为2.03%、Fe3+为0.83%。平均回收率Na ̄+为98.26%、Fe3+为97.62%。本法简便、快速、准确、选择性好。  相似文献   

9.
基于存在增效剂十六烷基三甲基溴化铵,铬(Ⅵ)催化过氧化氢氧化茜素红的反应,拟定了测量痕量铬(Ⅵ)的新催化光度法,本法由于添加了十六烷基三甲基溴化铵,灵敏度提高4.8倍。测定铬(Ⅵ)含量线性范围为0.010 ̄0.090mg/L;检出限为8.8×10^-4mg/L;相对标准偏差为1.9%(n=9)方法,可用于测定水样中的铬(Ⅵ)。  相似文献   

10.
本文采用单柱离子色谱系统测定了C2O^2-4,以1.3mmol/L葡萄糖酸钠/1.3mmol/L硼砂为淋洗液测定C2O^2-4,8常见阴离子Cl^-,NO^-3,HPO^2-4,SO^2-4不干扰测定,C2O^2-4的检出限为0.57mg/L,相对标准偏差为1.07%,工作曲线的线性范围为0.57-500mg/L,应用本方法测定了加C2O^2-4的自来水样,C2O^2-4的回收率为99.52%。  相似文献   

11.
多环芳二酐型聚酯亚胺膜的透气性能李悦生,丁孟贤,徐纪平(浙江大学高分子科学与工程研究所,杭州,310027)(中国科学院长春应用化学研究所)关键词聚醚酰亚胺,聚酯酰亚胺,膜,透气性通常的聚酰亚胺加工性能较差,在芳环二酐的苯环间引入醚键等柔性基团后,其...  相似文献   

12.
13.
微量元素与疾病诊断治疗的研究现状及展望   总被引:8,自引:0,他引:8  
对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述,包括:微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。  相似文献   

14.
A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg?1, the maximum residue level of European Union for quizalofop-p-ethyl).  相似文献   

15.
Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.  相似文献   

16.
朱劲波  马立群  梁飞  苗迎春  王立民 《应用化学》2015,32(11):1221-1230
Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB5型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。  相似文献   

17.
钒与糖代谢及糖尿病   总被引:1,自引:0,他引:1  
微量元素钒作为生物体内必需元素,经证实有很重要的生理学功能,与机体糖代谢有十分密切的关系,且能降低糖尿病动物模型的高血糖,极有可能被开发为治疗糖尿病的药物。  相似文献   

18.
The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R2UPh type and -thioureas of the R2TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.  相似文献   

19.
Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection.  相似文献   

20.
In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.  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