同时测定海水中K+、Na+、Ca2+、Cl-的流动注射离子选择电极分析

建立了一种用于海水中K+、Na+、Ca2+、Cl-同时快速、自动测定的流动注射离子选择电极自动方法(FI-ISE-M),优化了方法的最佳条件:总离子强度调节液(TISAB)的组成为0.3 mmol/L K+、6.0 mmol/L Na+、1.4 mmol/L Ca2+、21.0 mmol/L Cl-及pH8.0的80 mmol/L的tris-H3BO3缓冲溶液,其流量为1.25mL/min;每次测定的样品用量仅为160μL,载流流量为1.42 mL/min,混合盘管长度为30cm(I.D.0.5 mm)。本方法的分析速度为100样/h,相对标准偏差为2.0%(n=11),标准添加回收率为94.9%～104.3%,测定范围分别为1.0～8.0 mmol/L K+、50～290 mmol/L Na+、3.2～16.0 mmol/L Ca2+、70～430 mmol/LCl-。本方法已应用于反渗透海水淡化系统的水质检测。     

毛细管区带电泳技术快速分离检测爆炸残留物中的无机离子

利用间接紫外毛细管区带电泳方法完成了对爆炸残留物中7种无机离子(K+,NH+4,NO-2,NO-3,SO2-4,ClO-3,ClO-4)的分离检测。阳离子测定采用的缓冲体系为10 mmol/L吡啶（pH 4.5）-3 mmol/L冠醚,K+和NH+4在2.6 min内达到基线分离,检出限分别为0.25 mg/L和0.10 mg/L(S/N=3)。阴离子测定采用的缓冲体系为40 mmol/L硼酸-1.8 mmol/L重铬酸钾-2 mmol/L硼酸钠（pH 8.6）,氢氧化四甲铵为电渗流改性剂,5种阴离子在4.6 min内达到基线分离,检出限为0.10～1.85 mg/L。该方法已成功地应用于实际爆炸物样品种类的判定分析,取得了很好的结果。     

毛细管区带电泳技术快速分离检测爆炸残留物中的无机离子

利用间接紫外毛细管区带电泳方法完成了对爆炸残留物中7种无机离子(K+,NH+4,NO-2,NO-3,SO2-4,ClO-3,ClO-4)的分离检测。阳离子测定采用的缓冲体系为10 mmol/L吡啶（pH 4.5）-3 mmol/L冠醚,K+和NH+4在2.6 min内达到基线分离,检出限分别为0.25 mg/L和0.10 mg/L(S/N=3)。阴离子测定采用的缓冲体系为40 mmol/L硼酸-1.8 mmol/L重铬酸钾-2 mmol/L硼酸钠（pH 8.6）,氢氧化四甲铵为电渗流改性剂,5种阴离子在4.6 min内达到基线分离,检出限为0.10～1.85 mg/L。该方法已成功地应用于实际爆炸物样品种类的判定分析,取得了很好的结果。     

化妆品中阴阳离子的快速测定及其用于化妆品鉴别的研究

用离子色谱电导检测器对黑泥类化妆品中的阴、阳离子(Na+,NH+4,K+,Mg 2+ ,Ca 2+ ,Cl-,Br-,NO-2,NO-3和SO 2- 4)进行了测定。阳离子分离条件: 阳离子交换柱ICS C25,均苯四甲酸淋洗液浓度2.0 mmol/L ,流速0.6 mL/min ;阴离子分离条件: 阴离子交换柱Shim pack IC A1,淋洗液为2.5 mmol/L 邻苯二甲酸和2.4 mmol/L 三羟基氨基甲烷,流速1.0 mL/min 。结果表明,上述10种离子在较宽浓度范围内有良好     

毛细管电泳-安培法测定复方磺胺甲噁唑片中的有效成分

采用毛细管电泳-安培法(CE-AD)同时分离测定了磺胺甲噁唑(sulfamethoxazole,SMZ)、磺胺嘧啶(sulfadiazine,SD)和抗菌增效剂甲氧苄胺嘧啶(trimethoprim,TMP)3种常用磺胺类抗菌药物成分,考察了实验参数对分离、检测体系的影响。在优化实验条件下,以300μm碳圆盘电极作为工作电极,检测电位为1050mV(vs.SCE),在Na2B4O7(13mmol/L)-KH2PO4(18mmol/L)(pH5.8)的缓冲溶液中,分离电压18kV,进样6s,3组分在14min内可实现基线分离。上述3组分浓度分别在5×10-4~5×10-2、5×10-4~0.1和5×10-4~5×10-2g/L范围内与其峰电流强度呈线性关系,检出限达5.1×10-5~8.0×10-5g/L(S/N=3)。该方法已成功应用于复方磺胺甲噁唑片中抗菌活性成分的含量测定,结果令人满意。     

直接电沉积金纳米粒子修饰氧化铟锡电极测定亚硝酸根

以电化学沉积法一步制得了金纳米粒子(GNP)修饰氧化铟锡(ITO)电极,采用紫外、扫描电镜及循环伏安法对GNP/ITO修饰电极进行了表征。结果表明,金纳米粒子在ITO电极表面呈球形,分布均匀无团聚,粒径约30 nm。该修饰电极具有良好的电化学性能,在pH 2.2的Na2HPO4-柠檬酸缓冲溶液中其氧化峰电流与NO2-的浓度呈良好的线性关系,线性范围为5×10-6~5.5×10-4mol/L,线性回归方程为:i(μA)=1.07 136C(mmol/L),相关系数r=0.9969;检出限可达1.0×10-6mol/L。该修饰电极用于废水中NO2-的测定,结果令人满意。     

离子色谱法测定中药女贞子浸煮液中的碱金属和碱土金属

用离子色谱法测定了中药女贞子水浸煮液中K+、Na+、Ca2+、Mg2+的含量,色谱柱为IonPAC CS 12A(4 mm×250 mm)阳离子交换柱,淋洗液为11.0 mmol/L的硫酸溶液,流速1.00mL/min,电导检测器检测。结果表明,4种离子的检出限分别为:Na+0.021 mg/L,K+0.020 mg/L、Mg2+0.015 mg/L,Ca2+0.100 mg/L,相对标准偏差在0.72%~3.92%之间,回收率为98.3%~103.1%。结论:该法操作简便、快速,准确,为测定其它中药中Na+、K+、Mg2+、Ca2+的含量提供了一种有效的方法。     

毛细管电泳安培检测法测定儿茶中的儿茶素,表儿茶素

用毛细管电泳安培检测法同时测定了中药儿茶中儿茶素和表儿茶素的含量,研究了各种实验条件对分离效果的影响,得到了优化的实验条件.以直径为50 μm的碳纤维微电极为工作电极,电极电位为+1.2V(vs.Ag/AgCl),20mmol/L的Na2B4O7-H3BO3(pH值为8.4)+80 mmol/L SDS为缓冲溶液.在此条件下,儿茶素和表儿茶素在10 min内得到了良好的分离.儿茶素和表儿茶素分别在5.0×10-3～0.5mg/mL浓度范围内与电泳峰电流呈现良好线性关系,检测下限分别为0.1 mg/mL和0.05 mg/mL.将之应用于实际样品的测定.     

离子色谱法测定AgNO3中的微量Cl-、NO2-和SO42-

用离子色谱法测定AgNO3溶液中的Cl^-、NO2^-和SO4^2-，以5.0mmol/L Na2CO3-5.0mmol/L NaHCO3混合溶液作淋洗液，采用离子交换法将AgNO3转换成KNO3，以除去Ag ^ 。讨论了NO3^-对Cl^-、NO2^-和SO4^2-测定的影响。AgNO3溶液中Cl^-、NO2^-和SO4^2-的回收率分别为93.3%、108%和94%。     

反向毛细管电泳高频电导法测定牛黄中的胆酸

建立了毛细管电泳高频电导法快速简便测定牛黄粉中胆酸的新方法.考察了电泳介质的种类、浓度、 pH值以及操作电压和进样时间对分离检测的影响.缓冲液为0.5 mmol/L Na3PO4 2 mmol/L Na2HPO4 0.2 mmol/L CTAB(pH 11.7), 分离电压为 -15 kV时可实现较好的分离和检测.胆酸的线性范围为75～200 μg/mL, 检出限为0.1 μg/mL.线性方程为y=0.6054ρ-4.14991, r=0.953.回收率为100.9%, RSD(n=5)=2.1%.     

Plasma-polymerized membrane electrode for the determination of dextromethorphan and dimemorfan

Ion-selective electrodes (ISEs) responsive to the antitussives dextromethorphan and dimemorfan were constructed by the fixation of an ion-exchanger, ammonium tetraphenylborate, on a Millipore membrane by means of a plasma-polymerization technique. The electrodes showed a Nernstian response over the range of 10(-5)-10(-2) M dextromethorphan and dimemorphan, and the working pH range was 5-7. The interference from common cations such as Na+, K+ and Ca2+ was negligible but some organic cations interfered weakly. The electrodes were applied successfully for the determination of the drugs in pharmaceutical preparations.     

吡咯并[2,1,5-cd]中氮茚酰腙衍生物的合成及Cu2+荧光探针行为

设计合成了吡咯并[2,1,5-cd]中氮茚酰腙衍生物6. 测试了其紫外光谱和荧光光谱, 研究了其对铜离子的选择性识别作用. 结果表明, 化合物6作为铜离子荧光探针, 受常见离子干扰较小, 对于铜离子有着较高的选择性和较低的检出限.     

Use of mobile phase 18-crown-6 to improve peak resolution between mono- and divalent metal and amine cations in ion chromatography

It is difficult to quantify NH4+ by ion chromatography in the presence of high concentrations of Na+ due to peak overlap. The Dionex IonPac CS15 column, which contains phosphonate, carboxylate, and 18-crown-6 functional groups, was originally developed to overcome this problem. We have found that the addition of 18-crown-6 to the eluent promotes improved peak resolution between Na+ and NH4+ even at concentrations as high as 60,000 to 1 using this column. Its use also improves the separation of alkali and alkaline earth metal and amine cations. Mobile phase 18-crown-6 increased the retention times of CH3NH3+, NH4+, and K+, and decreased the retention time of Sr2+. The retention times of Li+, Na+, Mg2+, Ca2+, (CH3)2NH2+, and (CH3)3NH+ were not affected. This method makes possible the direct analysis of ammonia from nitrogenase, the enzyme responsible for biological nitrogen fixation. The resolution of the NH4+ peak from the Na+ and Mg2+ peaks improved from zero resolution to values of 6.19 and 5.65, respectively. This technique considerably reduces the analysis time of NH4+ in the presence of high concentrations of Mg2+ and Na+ over traditional indophenol measurements.     

Primary amine drug selective electrodes with special crown ethers as neutral carriers

Ionophores selectively sensitive to primary amines have been synthesized which display low potentiometric selectivity coefficients for K+, Na+ and NH4+ ions, secondary and tertiary amines as well as quaternary ammonium ions. These ionophores include macrocyclic polyethers with dinaphthyl subunits and azocrown ether with nitrogen donor atoms. The feasibility of these ionophores for preparing primary amine drug selective electrodes was investigated in detail. Practically usable PVC membrane electrodes sensitive to primary amine drugs, such as mexiletine, dopamine, metaraminol and tryptamine, and aliphatic primary amines have been prepared with these ionophores as neutral carriers. Direct potentiometric methods for assaying these drugs have been proposed by using the prepared electrodes. The proposed primary amine drug selective electrodes are remarkably superior to those based on ion-associates. Compared with the electrodes based on common ethers, the interference by K+, Na+ and NH4+ ions is substantially reduced. A digital simulation of the electrochemical process concerning the membrane transport was performed and some interesting conclusions have been drawn.     

The diamond/aqueous electrolyte interface: an impedance investigation

We have investigated the electrochemical interface between diamond electrodes and aqueous electrolytes using electrochemical techniques such as cyclic voltammetry and ac impedance spectroscopy. High-quality CVD-grown boron-doped polycrystalline diamond electrodes and IIa single crystalline natural diamond electrodes have been used in this study. In the case of hydrogen-terminated diamond electrodes, the electrochemical interface is dominated by the electrochemical double layer. Frequency-dependent impedance spectroscopy reveals a potential regime in which the contribution of ion adsorption becomes relevant. We have conducted experiments to evaluate the effect of pH and ionic strength on the double layer. Our results suggest that only ions resulting from water auto-dissociation, i.e., hydroxide and hydronium ions, are responsible for ion adsorption and, thus, able to modify the charge at the double layer. In contrast, no effect of the adsorption of several dissolved ions (such as Na+, K+, Cl-) has been observed On the basis of the electrochemical characterization of H-terminated diamond surfaces, we also discuss the phenomenon of the surface conductivity in diamond, as well as the pH sensitivity of the diamond surface. The influence of the O2/OH- and H2/H3O+ redox couples on the origin of the surface conductivity is discussed.     

固相配位化学反应研究 XXIII: 一取代基五氰合铁(II)类配合物热分解反应的研究

本文以气相色谱法为主要手段, 配合Mossbauer谱、红外光谱等结构分析方法, 研究了一系列一取代基五氰合铁(II)类配合物Na2[Fe(CN)5L]·mH2O及Na3[Fe(CN)5L']·nH2O(L=NO^+、N2H5^+、enH^+, L'=NH3、H2O、Py)的热分解反应。结果表明所有一取代五氰合铁(II)配合物热分解过程中都形成相同的中间化合物Na4[Fe(CN)6]和Fe2[Fe(CN)6], 各配合物热分解放出取代基L(L')的温度次序与L(L')在光谱化学序列中的次序一致。本文以亚硝基铁氰化钠为代表, 详细讨论了该系列配合物的热分解反应机理以及热稳定性的规律性。     

Rhodamine-derived Schiff base for the selective determination of mercuric ions in water media

A new rhodamine-derived Schiff base (RS) was synthesized and its sensing property to metal ions was investigated by UV/vis and fluorescence spectroscopies. Addition of Hg2+ ions to the aqueous solution of RS gave a visual color change as well as significantly fluorescent enhancement, while other ions including Pb2+, Cd2+, Cr3+, Zn2+, Cu2+, Fe2+, Co3+, Ni2+, Ca2+, Mg2+, K+ and Na+ ions did not induce any distinct color/spectral changes, which constituted a Hg2+-selective fluorescent OFF-ON chemosensor. The Hg2+-induced ring-opening of spirolactam of rhodamine in RS resulted in the dual chromo- and fluorogenic observation.     

铁氰酸镍膜修饰金电极的研制及应用

通过层层组装的方法,将Ni^2＋和[Fe（CN）6]^3-交替沉积在巯基乙酸功能化的金电极表面．首次成功制备了铁氰酸镍多层膜修饰电极,用循环伏安法研究了该多层膜的电化学行为,实验表明峰电流随膜层数的增加而增加,膜均匀增长．该修饰电极对一价金属离子Na^＋,K^＋,NH4^＋具有选择性响应,尤其对K^＋存在准能斯特响应,响应范围0．01～1．0mol／L;而且该电极对抗坏血酸（AA）和S2O3^2-体系的氧化具有良好的电催化作用,线性范围分别为：1．14×10^-4～1．14×10^-3mol／L和5．0×10^-4～3．1×10^-3mol／L．     

Neutral bidentate organophosphorus compounds as novel ionophores for potentiometric membrane sensors for barium(II)

Bis(diarylphosphine oxide) naphthalene compounds are used as novel ionophores in plasticized poly(vinyl chloride) matrix membrane sensors for barium ions. The most favorable sensor was 1,2-bis(diethylphenylphosphine oxide)naphthalene containing potassium tetrakis(4-chlorophenyl)borate as lipophilic salt and o-nitrophenyloctyl ether as plasticizer for ion-selective electrode membrane construction. The electrode showed excellent properties. It gave a linear response with a Nernstian slope of 30 mV per decade within the concentration range 10(-1)-10(-5) mol L(-1) BaCl2. The electrode exhibits a high selectivity towards Ba2+ with respect to Li+, Na+, K+, Rb+, Cs+, NH4+, Ag+, Mg2+, Ca2+, Sr2+, Mn2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+, Al3+, La3+, and Ce3+ ions. The electrode response was stable over a wide pH range (3-11). The lifetime of the electrode was about 2 months. It was successfully applied to the determination of Ba2+ contents in some rocks.     

铊(I)离子选择电极动力学分析法测定超痕量铁

Fe(II) induces the reaction between Tl3+ and H2O2. The rate of reaction is linearly proportional to the concentration of Fe2+ in the range 2.5 ?10-9-2.5 ?10-8 mol dm-3 (20? and 5 ?10-9-5 ?10-8 mol dm-3 (15?. The standard deviation is less than 0.071 ?10-8. A 1000-fold excess of Zn2+, Cd2+, Mg2+, Ni2+, Pb2+, Ba2+, Ca2+, Li+, Na+, Ag+, NO3-, SO42-, AcO-, HPO42-, 500-fold excess of Al3+, Fe3+, Co2+, Hg2+ and 100-fold excess of Ti4+, Cr3+, Cu2+, Br-, Cl- can be tolerated, but reducing agents such as (NH2)2SO4, NH2OH.HCl interfered. This kinetic method was applied to determine Fe(II) in standard zinc sample and fountain water, with satisfactory results.