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 839 毫秒
1.
增敏荧光光谱法测定复方新诺明中的磺胺甲(口恶)唑   总被引:2,自引:0,他引:2  
提出了在溴化十六烷基三甲铵(CTAB)存在下,PH为4.0的HAc-NaAc缓冲溶液中,增敏荧光光谱法测定复方新诺明中磺胺甲恶唑(SMZ)含量的新方法。碘胺甲恶唑浓度在0.08-0.8μg/mL范围内,荧光强度与碘胺甲恶唑浓度呈良好的一性关系。方法的检出限为0.016μg/mL(6.32*10^-8mol/L)。方法已用于测定复方新诺明中磺胺甲恶唑的含量。  相似文献   

2.
薄层分离-库仑滴定法测定茄尼醇   总被引:17,自引:0,他引:17  
提出以2mol/LKBr-醋酸(1:3V/V)为电液,在阳极电生溴与尼醇发生反应来测定茄尼醇含量的库仑滴定法。茄尼醇与溴反应,其n值为18,对于烟叶以物中茄尼醇,以正己烷-二氯乙烷-丙醇为展开剂,用薄层色地邓以分离,用库仑滴定法进行测定 。  相似文献   

3.
聚氯乙烯膜奎宁选择电极的研制与应用   总被引:4,自引:0,他引:4  
李东辉  丁杨栋 《分析化学》1995,23(11):1271-1273
本报道了一种以奎宁溴汞酸盐为电活性物的PVC膜奎宁选择电极,其线性响应范围为1.0×10^-2-1.0×10^-6mol/L;级差58±1mV;检测限为8.2×10^-7mol/L。以此电极测定奎宁的含量,方法简单、快速、结果与药典法相符。  相似文献   

4.
磺胺甲恶唑的二阶导数差示脉冲极谱法测定   总被引:3,自引:0,他引:3  
梁云爱  孙金辉 《分析化学》2000,28(9):1136-1139
建立了磺胺甲恶唑的二阶导数差示脉冲极谱定量分析方法,磺胺甲恶唑在10%HCl-(硼酸-氯化钾缓冲溶液)-水(5:5:90)的底液中,于-1.45V(vs.Ag/AgCl)处出现一良好的二阶导数差示脉冲极谱峰,磺胺甲恶唑浓度与其峰高在0.08~0.80mmol/L范围内呈线性关系(p〈0.01),检测限为8.6nmol/L。本法简便、快速、灵敏、结果准确。  相似文献   

5.
玉米素和激动素的伏安行为   总被引:1,自引:0,他引:1  
玉米素和激动素在0.1mol/L的醋酸-醋酸钠底液里能还原,产生很好的极谱峰,检测灵敏度可达2.5×10^-^8mol/L,峰电位分别为-1.18V和-1.17V(对Ag/AgCl)。测定了电极反应决定步骤的αnα和电化学反应的标准速率常数ks,研究了它们对Cu^2^+,Eu^3^+,Cd^2^+,Zn^2^+的电极不产生的影响。  相似文献   

6.
本文研究了利用亚硝基R盐螯合形成的树脂,分离富集试液中痕量贵金属元素铱的实验条件。并利用JP-1型示波极谱仪,在1.50mol/L盐酸+5.0×10^-5mol/L硫脲+0.2mol/L盐酸+5.0×10^-5mol/L硫脲+0.2mol/L碘化钾+碲(ρ(B)=0.4mg/L)的混合底液中,对铱进行极谱催化波测定。在示波极谱仪上峰电位约-0.55V(银汞齐为参比电极),可测定试液中5.0×1.0  相似文献   

7.
徐达峰  黄超伦 《分析化学》1994,22(6):596-598
本以石墨棒为导电基体,以硅钨酸,林可霉素为电活性和的制成了全固态林可霉素离子选择电极。所制电极在1.0×10^-1-5.0×10^-5mol/L浓度范围内有线性响应,斜率为58.3mV/pC,检测下限为2.5×10^-5mol/L。电极响应迅速,具有良好的稳定性,可用于林可霉素含量的快速测定。  相似文献   

8.
报道了α-苯偶酰二肟修饰碳湖电极的制 及对合成水样中铜的测定,在PH4.1的B-R缓冲溶液中通过在-1.20V电位下富集Cu^2+后,在-0.2 ̄+0.2电位一范围内作阳极溶出伏安法测定。在+0.048V处有一灵敏的氧化峰,峰电流与Cu^2+浓度在1×10^-7 ̄1×10^mol/L范围内成良好的线性关系,检出限为5×^-8mol/L。  相似文献   

9.
锌柱还原分光光度法测定微量砷   总被引:4,自引:0,他引:4  
俞长兴  高英立 《分析化学》1997,25(5):531-533
对锌柱还原砷及其测定进行了研究,胂化氢以Ag^+-PVA-EtOH-H2O为吸收液,在λmax400nm处进行吸光度测定,砷在0-1.8mg/L范围内与吸光度呈良好线性关系,其ε=8.7×10^4L.mol^-1.cm^-1。检出限为24μg/L。  相似文献   

10.
复方新诺明片剂中有效成分的毛细管区带电泳快速测定法   总被引:4,自引:0,他引:4  
研究了用毛细管区带电泳法快速测定复方新诺明片中磺胺甲恶唑(SMZ)和甲氧苄氨嘧啶(TMP)的含量。使用长27cm(有效长度20cm)内径50μm的石英毛细管,25kV分离电压,在0.05mol/L的乙酸盐缓冲液(pH5.5)中,上述两组分可在1.5min内完全分离。用紫外检测器在214nm处检测,外标法定量。10次检测含有141.7mg/LSMZ和25.6mg/LTMP的试样溶液,相对标准偏差为1  相似文献   

11.
研究了salen型席夫结构的荧光探针N,N’-二(2-羟基-1-萘甲醛)-l,2-苯二胺(NAPPDIH)对Cr3+的响应。Cr3+能够使该探针的荧光猝灭。研究表明,在pH3.5(乙酸胺-盐酸)和DMSO/H2O(V/V,8:2)的条件下,8.0×10-6 mol/L的Cr3+可以导致NAPPDIH 65%的荧光猝灭。并且,Cr3+的浓度在5.0×10-7~8.0×10-6 mol/L的范围内,与荧光强度的变化值呈良好的线性关系,检出限为3.7×10-7 mol/L。方法可用于直接检测水样中的Cr3+。  相似文献   

12.
聚氯乙烯膜修饰碳微电极的研制及应用   总被引:7,自引:0,他引:7  
但德忠  陈文  龚峰景  徐峰  王正猛 《分析化学》2000,28(9):1150-1154
采用浸涂流延法制得PVC膜修饰碳微电极,用K3Fe(CN)6的循环伏安图考察了电极的电化学性能,并用此电极建立了环境水样中痕量汞的阳极溶出伏安法测定。在0.06mol/L KSCN+0.01mol/LKCl介质中,富集电位-0.80V,搅拌富集时间300s,扫描电压范围-0.20~0.40V,扫描速率314mV/s,咄峰电流与Hg^2+浓度在0.01~2.0mg/L的范围内有良好的线性关系,本电极  相似文献   

13.
本文建立了在铋膜修饰电极上采用方波吸附溶出伏安法同时测定纺织品中痕量Co2+和Ni2+的方法.以NH3-NH4Cl作为缓冲液,在丁二酮肟浓度为10 μmol/L的体系中,Co2和Ni2+的还原峰电位分别为-1.13 V和-1.03 V.当缓冲溶液pH为9.2,富集电位为-0.7V,富集时间为200 s时,C02 +和Ni2+在0.5~50 μg/L范围呈现良好的线性关系,相关系数R2>0.99,其检出限分别为0.79 μg/L和0.96 μg/L,其它金属离子的干扰较小.采用标准加入法测定纺织品中Co>和Ni2+,回收率在94.88%~104.14%之间.  相似文献   

14.
《Electroanalysis》2018,30(8):1880-1885
This work presents a simple and low‐cost method for fast and selective determination of Verapamil (VP) in tablets and human urine samples using a boron‐doped diamond working electrode (BDD) coupled to a flow injection analysis system with multiple pulse amperometric detection (FIA‐MPA). The electrochemical behaviour of VP in 0.1 mol L−1 sulfuric acid showed three merged oxidation peaks at around +1.4 V and upon reverse scan, one reduction peak at 0.0 V (vs. Ag/AgCl). The MPA detection was performed applying a sequence of three potential pulses on BDD electrode: (1) at +1.6 V for VP oxidation, (2) at +0.2 V for reduction of the oxidized product and (3) at +0.1 V for cleaning of the working electrode surface. The FIA system was optimized with injection volume of 150 μL and flow rate of 3.5 mL min−1. The method showed a linear range from 0.8 to 40.0 μmol L−1 (R>0.99) with a low limit of detection of 0.16 μmol L−1, good repeatability (RSD<2.2 %; n=10) and sample throughput (45 h−1). Selective determination of VP in urine was performed at+0.2 V due to absence of interference from ascorbic and uric acids in this potential. The addition‐recovery tests in both samples were close to 100 % and the results were similar to an official method.  相似文献   

15.
选用1-乙烯基-3-乙基咪唑四氟硼酸盐([VElm]BF4,一种离子液体)作为功能单体,以Co2+为介导离子,结合1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4)/二甲基亚砜(DMSO)二元致孔体系制备了绿原酸印迹整体柱。经过对制备参数的考察,确定最佳比例为绿原酸:Co2+:[VElm]BF4:EDMA(乙二醇二甲基丙烯酸酯)(摩尔比)=1:1:5:20,[BMIM]BF4:DMSO=3:1(V/V),最大印迹因子达2.10。通过优化色谱条件,最终在乙腈:20 mmol/L乙酸钠缓冲液(pH 4.2)=70:30(V/V)时实现了绿原酸及其类似物的完全分离。由此可见,以离子液体为功能单体及致孔剂,在金属介导策略下制备的分子印迹聚合物可实现绿原酸的特异性识别及分离。  相似文献   

16.
茜素修饰碳糊电极吸附伏安法测定痕量铜   总被引:3,自引:0,他引:3  
报道了采用茜素修饰碳糊电极测定痕量铜的阳极溶出伏安法。在浓度为0 .1 mol/L 的 HAc- Na Ac缓冲溶液 (p H4.5)中 ,于 +0 .1 0 V处富集 ,- 0 .30 V还原后再进行阳极化扫描 ,于 - 0 .0 5V处获得一灵敏的铜的溶出峰 ,二次导数峰电流与铜浓度在 1 .6× 1 0 -9mol/L~ 4.7× 1 0 -7mol/L范围内呈线性关系 ,检出限达 8.0× 1 0 -10 mol/L。同时 ,对电极反应机理进行了讨论。方法应用于锌合金中铜的测定。  相似文献   

17.
The combination of scanning electrochemical microscopy (SECM) with piezoelectric quartz crystal impedance (PQCI) analysis was proposed as a novel multiparameter method for investigating the cyclic voltammetric growth of poly(o-phenylenediamine) (PoPD) thin films at Au electrodes in aqueous solutions of various pH values and the potentiostatic microetching (localized degradation) of these films in 0.10 mol/L aqueous H2SO4 for comparative examinations on polymer porosity and stability. Two potential-sweep ranges, -0.4 to 0.9 (I) and 0 to 0.9 (II) V versus SCE, and four solutions, acidic (A, 0.20 mol/L H2SO4 + 0.10 mol/L Na2SO4; B, 0.10 mol/L H2SO4 + 0.20 mol/L Na2SO4), neutral (C, 0.10 mol/L PBS + 0.20 mol/L Na2SO4, pH 7.2), and alkaline (D, 0.20 mol/L NaOH + 0.20 mol/L Na2SO4) aqueous solutions, were selected for PoPD growth. The pH increase for the polymerization solution increased the molar percentage of polyaniline-like chains in PoPD, as quantified from the current peaks at approximately 0.6 V versus a saturated calomel electrode (SCE) for the oxidation of -NH2 groups in as-prepared PoPD (grown from solutions C and D) during their redox switching in 0.10 mol/L aqueous H2SO4 for the first time. The unusual PQCI responses observed at negative potentials (potential range I) in the first several potential cycles during the cyclic voltammetric growth of PoPD in acidic and neutral solutions have been reasonably explained as being due to the precipitation/dissolution of the poorly soluble phenazinehydrine charge-transfer complexes developed during redox switching of oligomers for the first time, which brought about much less compact PoPD films and their higher degradability than those grown in the same solution but over potential range II. SECM, scanning electron microscopy (SEM), and piezoelectric quartz crystal (PQC) frequency were used to estimate the sizes of etched microscale spots. In addition, the x-, y-, or z-axis movement of a Pt microelectrode of 25-mum diameter near the PQC electrode was found to influence negligibly the PQCI responses in 1.0 mol/L aqueous Na2SO4 containing K4Fe(CN)6 up to 0.10 mol/L, and a new protocol of dynamically electrodepositing silver microwires via the chemical-lens method was proposed for examining the local mass-sensitivity distribution on the PQC surface.  相似文献   

18.
冯谙  范利军  蔡陶  李文坡 《应用化学》2015,32(9):1081-1087
采用计时电流法沉积纳米MnO2电极材料,利用Scharifker-Hills成核理论模型分析时间-电流(i-t)曲线判断了MnO2成核机理。 对3种不同的成核方式制得的MnO2材料进行电化学超级电容性能测试、用SEM观察了其微观形貌。 比较了不同沉积方法对沉积材料结构、电容性能的影响。 计时电流测试发现,在0.1 mol/L Mn2+溶液中,电势阶跃至0.365 V,初始成核符合瞬时成核机理,在0.01 mol/L Mn2+溶液中,电势阶跃至0.418 V,初始成核存在瞬时成核和连续成核两种不同机理,在0.5 mmol/L Mn2+溶液中,电势阶跃至0.515 V,初始成核则符合连续成核机理。 超级电容性能测试发现,瞬时成核下制得的MnO2电极材料相对于另外两种成核方式得到的电极材料具有更好的电容性能,这是因为瞬时成核更易于形成多孔、纳米片(棒)状等高比表面积的沉积物,表明制备方法影响MnO2电极材料电容性能。  相似文献   

19.
Based on single‐walled carbon nanotubes (SWCNTs) modified glassy carbon electrode (GCE/SWCNTs), a novel method was presented for the determination of L ‐tyrosine. The GCE/SWCNTs exhibited remarkable catalytic and enhanced effects on the oxidation of L ‐tyrosine. In 0.10 mol/L citric acid‐sodium citrate buffer solution, the oxidation potential of L ‐tyrosine shifted negatively from +1.23 V at bare GCE to +0.76 V at GCE/SWCNTs. Under the optimized experimental conditions, the linear range of the modified electrode to the concentration of L ‐tyrosine was 5.0×10?6–2.0×10?5 mol/L (R1=0.9952) and 2.7×10?5–2.6×10?4 mol/L (R2=0.9998) with a detection limit of 9.3×10?8 mol/L. The kinetic parameters such as α (charge transfer coefficient) and D (diffusion coefficient) were evaluated to be 0.66, 9.82×10?5 cm2 s?1, respectively. And the electrochemical mechanism of L ‐tyrosine was also discussed.  相似文献   

20.
姜黄素的电化学性质及其测定   总被引:4,自引:1,他引:3  
吴萍  陈伟  张亚锋  林新华 《电化学》2005,11(3):346-349
在0.1 mol/L磷酸盐缓冲液(pH 3.0)中,姜黄素于玻碳电极上存在可逆的单电子转移过程,据此,本文建立了以差示脉冲伏安扫描法检测姜黄素含量的新方法.在+0.8V(vs.SCE)电位下,含姜黄素的电解液(试样)于玻碳电极上经过富集,可得一灵敏的还原峰,峰电位Ep为+0.386V.峰电流Ip与姜黄素浓度(1.0×10-8~2.5×10-7mol/L范围内)成线性关系,最低检出限为4.0×10-9mol/L.本法操作简单、快速、灵敏、准确,可用于药物中姜黄素含量直接测定.  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