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1.
阐述了TW灵芝在液体深层培养中,进行富集碘实验过程菌丝体多糖含量的变化.实验表明,在TW灵芝液体培养中添加1000×10-6~8000×10-6浓度的碘化钾,菌丝体多糖含量为0.92%~1.58%.  相似文献   

2.
对82名苯作业工人和100名对照组工人的发铁、发锌和发铜含量水平进行了研究。结果揭示,油漆作业工人发铁含量为10.3×10-6±2.3×10-6,明显低于对照组(14.4×10-6±3.1×10-6).P<0.01,发铜含量为7.4×10-6±1.2×10-6,亦低于对照组(9.8×10-6±1.3×10-6).P<0.05;发锌含量为169.2×10-6±26×10-6,与对照组(172.5×10-6±28×10-6)基本相同,P>0.05.  相似文献   

3.
本文报道了(1)十二种云南高档和普通香烟含氟量为5.4434×10-6~8.584×10-6,平均7.223±0.9940×10-6,湖南笑梅、More香烟含氟显为12.542×10-6和6.148×10-6;(2)用高氟玉米和小麦酿造的60°和50°白酒,含氟量分别为0.074±0.004mg/L和0.076±0.006mg/L;(3)西双版纳和广东大丰咖啡及雀巢咖啡含氟量范围1.672×10-6~4.446×10-6,平均3.110×10-6±1.306×10-6;(4)昆明市售花茶、红茶、绿茶、砖茶共30份,含氟量分别为75.5×10-6±7.07×10-6、10.4.13×10-6±60.66×10-6、62.2×10-6±48.08×10-6和305.5×10-6。上述四种嗜好物品除茶叶含氟量高,饮茶过量会引起氟中毒外,其余三种与氟中毒关系不大.  相似文献   

4.
停流流动注射分析同时测定碘离子和亚硝酸根的研究   总被引:10,自引:0,他引:10  
柳仁民  刘桂华 《分析化学》1995,23(4):407-409
基于铁(Ⅲ)-硫氰酸根络合物褪色动力学反应,利用流动注射分析停流技术,建立了流动注射动力学分析法同时测定碘离子和亚硝酸根离子的新方法,方法对碘离子的线性范围为2×10^--1.6×10-4mol/L,对亚硝酸根的线性范围为4×10^-7-1×10mol/L。应用于全成混合液中碘离子和亚硝酸根的测定,结果满意。  相似文献   

5.
研究了在HCl介质中,Cr(Ⅵ)氧化碘离子显色反应的动力学条件,建立了测定Cr(Ⅵ)的非催化动力学分析法。方法的灵敏度7.27×10-7g·L-1,检测限5.33×10-6g·L-1,测定范围2×10-5~3×10-4g·L-1。用于测定标钢中的铬,测定值与标准值基本一致  相似文献   

6.
基于芘的荧光熄灭的单质碘荧光敏感膜的研究   总被引:8,自引:0,他引:8  
单质碘熄灭固定于增塑的PVC膜中的芘的荧光,且这种熄灭作用可逆。本据此研制了用于测定单质碘浓度的荧光敏感膜,最佳膜组成为2~4mg芘、50mgPVC粉、100mg邻苯二甲酸二异辛酯,测定碘的浓度范围为2.26×10^-5~1.04×10^-3mol/L。此膜测定单质碘的重现性好,响应时间小于40s。除Fe^3+、Bi^3+外,其它常见离子均无干扰。将此膜用于食盐中碘的测定,结果令人满意。  相似文献   

7.
极谱法快速同时测定锌电解液中微量铜、镉、钴   总被引:7,自引:0,他引:7  
铜、镉、钻在了丁二酮肟-氯化铵-柠檬酸钠-HAc-NaAc体系中有灵敏的极谱波。其峰电位分别为-0.24V、- 0.79V和-0.93V,线性范围分别为4 × 10~(-6)~ 4 × 10~(-3)、5 × 10~(-6)~ 5×10~(-3)、1×10~(-7)~1×10~(-4)g/L,检测限分别为2×10~(-6)、4 × 10~(-6)和5×10~(-8)g/L。方法无需预处理直接用于锌电解液中微量铜、镉、钴的测定,结果令人满意。  相似文献   

8.
乳酸环丙沙星单扫描示波极谱法研究   总被引:3,自引:0,他引:3  
研究了乳酸环丙沙星的极谱伏安行为,在pH=8.3的0.02mol/L,NH4Cl-NH3.H2O底液中,乳酸环丙沙星能产生1个灵敏的还原峰,峰电位为-1.61V,其导数峰高与浓度在3.9×10^-8~1.8×10^-6mol/L和1.8×10^6~1.1×10^-5mol/L范围内呈现良好的线性关系,相关系数r=0.9997,检测下限为2.5×10^-8mol/L,用于乳酸环丙沙星注射液的测定,相  相似文献   

9.
吐温80—AuCl4^—化学发光新体系测定痕量碘离子的研究   总被引:6,自引:0,他引:6  
基于碘离子对吐温80-AuCl4^-体系化学发光的强烈抑制作用,提出了一种测定痕量碘离子的新的化学发光分析法。方法的线性范围和检测分别为1.2×10^-8 ̄1.0×10^-6g/mL和5.1×10^-9g/mL碘离子。拟定的方法体系简单,选择性好,加碘酱油和实际水样中碘离子的测定,结果满意。  相似文献   

10.
水浸泡对海带中碘含量的影响   总被引:3,自引:0,他引:3  
用能量色散X射线荧光分析法(XRF)研究了水浸泡对海带中碘含量的影响.结果表明,用淡水浸泡海带可使其中80%的碘损失掉,但仍含碘600×10-6~1200×10-6,每天食用1~2g经浸泡后的湿海带即可满足成人对碘的日需要量.延长浸泡时间或用盐水浸泡可使海带中碘含量少流失10%左右。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

13.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

14.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

15.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

16.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

17.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.  相似文献   

18.
19.
《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.  相似文献   

20.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

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