麦饭石修饰碳糊电极伏安法测定克林霉素

在pH=9的磷酸盐缓冲溶液(PBS)中,用麦饭石修饰碳糊电极循环伏安法研究了克林霉素的电化学性质,并讨论了影响克林霉素测定的各种因素,得到了其测定的最佳实验条件。克林霉素的氧化峰电位是0.80V,氧化峰电流与克林霉素的浓度在3.25×10-6～1.10×10-4 mol.L-1范围内呈良好的线性关系。该测定方法的检出限(S/N=3)为5.0×10-7 mol.L-1。用标准加入法测定回收率范围在94.9%～101.4%。克林霉素在0.80V处的氧化为1电子、1质子参加的受扩散控制的不可逆过程。克林霉素的电化学测定方法能很好地用于实际样品的测定而且结果与药典法一致。     

碳纳米纤维修饰碳糊电极用于双酚A的电化学检测

制备了碳纳米纤维修饰碳糊电极,并用于双酚A的高灵敏和高选择性电化学检测。碳纳米纤维材料经静电纺丝和碳化过程相结合制备而成,采用滴涂的方法修饰于碳糊电极表面制成电化学传感器。利用循环伏安法、交流阻抗法以及微分脉冲伏安法考察了传感器的性质及双酚A的电化学行为。结果表明,双酚A的峰电流响应与其浓度在0.8~50μmol/L之间呈良好的线性关系,检测限为0.1μmol/L。构建的电化学传感器用于环境水样中双酚A的检测具有较高的回收率。     

头孢氨苄在碳糊电极上的电化学行为及其分析研究

用循环伏安法和线性扫描伏安法研究了头孢氨苄在碳糊电极上的电化学行为,考察了不同电解质溶液、pH以及扫描速率等的影响。实验表明:在2.0 mol·L-1HCl支持电解质中,头孢氨苄的降解产物在-0.45 V(vs.SCE)处的电化学还原反应为2电子与2质子参加的受吸附控制的不可逆过程。还原峰电流与头孢氨苄的浓度的平方根在1.8×10-8～3.0×10-4mol·L-1范围内呈良好的线性关系,回收率在95.7%～101.5%范围,检出限(S/N=3)为1.0×10-8mol·L-1。并探讨了头孢氨苄在电极上的反应机理。     

靛红在碳糊电极上的阴极吸附伏安法研究

利用极谱分析仪,在0.40 mol/L的HAc-NaAc(pH 6.0)缓冲液中,发现靛红在碳糊电极(CPE)上有一灵敏的吸附伏安还原峰,峰电位为-0.44 V(vs.SCE)。该还原峰的二阶导数峰电流与靛红的浓度在4.0×10-8~1.0×10-7mol/L(富集90 s)范围内成良好的线性关系,相关系数为0.9954,检出限为8.0×10-9mol/L(S/N=3,富集110 s)。探讨了靛红在碳糊电极上的伏安性质和电极反应机理,并且成功应用于中草药青黛中靛红含量的测定。     

碳糊电极阳极吸附伏安法测定卡托普利

在0.40 mol/L的HAc-NaAc(pH=4.8)缓冲溶液中,卡托普利(Captopril,CPT)在碳糊电极(CPE)上有一灵敏的吸附氧化峰,峰电位为0.23 V(vs.SCE)。该氧化峰的二阶导数峰电流与卡托普利的浓度在2.0×10-8～1.0×10-6mol/L(富集90 s)范围内呈良好的线性关系,相关系数为0.9966,检出限为8.0×10-9mol/L,并成功应用于卡托普利片含量的测定。探讨了卡托普利在碳糊电极上的伏安性质和电极反应机理。     

Carbon Paste Electrode Modified by Surfactant for Anodic Stripping Voltammetric Determination of Sulphadiazine

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Voltammetric Determination of Selected Aminoquinolines Using Carbon Paste Electrode

Optimum conditions have been found for voltammetric determination of mutagenic 5‐aminoquinoline, 6‐aminoquinoline and 3‐aminoquinoline by differential pulse voltammetry and adsorptive stripping differential pulse voltammetry on carbon paste electrode. The lowest limits of determination were found for adsorptive stripping differential pulse voltammetry in 0.1 mol dm^?3 H₃PO₄ (5×10^?7 mol dm^?3 , 1×10^?7 mol dm^?3, and 1×10^?7 mol dm^?3 for 5‐aminoquinoline, 6‐aminoquinoline and 3‐aminoquinoline, respectively). The possibility to determine mixtures of 8‐aminoquinoline with 3‐aminoquinoline or 5‐aminoquinoline or 6‐aminoquinoline, and mixtures of 5‐aminoquinoline with 3‐aminoquinoline or 6‐aminoquinoline by differential pulse voltammetry was verified. Binary mixtures of 8‐aminoquinoline with 3‐aminoquinoline or 6‐aminoquinoline, and of 3‐aminoquinoline with 5‐aminoquinoline could be successfully analyzed.     

用混合粘合剂修饰的碳糊电极测定诺氟沙星

在pH10.50的磷酸盐缓冲溶液中 ,当含有0.8mmol/L的NH4Cl,8mg/L的SLS(十二烷基磺酸钠)时 ,诺氟沙星在由69.1% (w)的石墨粉、24.5 % (w)的液体石蜡和6.4 % (w)的甘油组成的混合粘合剂碳糊电极上产生一灵敏的阴极溶出还原峰 ,峰电位为 -1.61V ;峰电流与诺氟沙星浓度在8.0×10 -9～4.0×10 -7mol/L范围内呈良好的线性关系 ,相关系数为r=0.9949 ,检出限为3.0×10-9 mol/L ;该法用于测定诺氟沙星胶囊含量 ,结果令人满意     

碳糊电极阳极吸附伏安法测定诺氟沙星

报道了用碳糊电极阳极吸附伏安法测定诺氟沙星的方法。在0.40 mol.L-1的NH4OAc-HOAc(pH 4.51)缓冲溶液中,诺氟沙星在碳糊电极(CPE)上有一灵敏的吸附氧化峰,峰电位为1.16 V(vs.SCE)。该氧化峰的二阶导数峰电流与诺氟沙星的浓度在4.0×10-9~4.0×10-7mol.L-1(富集90 s)范围内呈线性关系,相关系数为0.996,检出限为1.0×10-9mol.L-1(S/N=3,富集110 s);应用于人体尿液中诺氟沙星含量的测定,方法的回收率为99.1%~104.0%。文中探讨了诺氟沙星在碳糊电极上的伏安性质和电极反应机理。     

Single-Sweep Voltammetric Determination of Tamoxifen at Carbon Paste Electrode

Abstract

A single-sweep voltammetric method was proposed for the determination of tamoxifen. The proposed method took advantage of both the accumulation of carbon paste electrode toward tamoxifen and the rapidity of single-sweep voltammetry. In HAc-NaAc (pH 4.1) buffer/methanol (85:15 v/v) mixed solution, an irreversible oxidation peak of tamoxifen was observed at 1.1 V (versus SCE). The second-order derivative peak current of tamoxifen and its concentration plots were rectilinear over the range of 7.0 × 10^?10 ～ 3.0 × 10^?8 mol · l^?1 with a detection limit of 1.0 × 10^?10 mol · l^?1 without any preconcentration. The proposed method was evaluated by analyzing tamoxifen citrate tablets, which was characterized by rapidity and higher sensitivity.     

Voltammetric Determination of Quercetin in Urine at Carbon Paste Electrode

Abstract

The electrochemical behavior of the quercetin (Q) at a carbon paste electrode (CPE) containing 15% paraffin oil is investigated. Square wave anodic stripping voltammetric (SWASV) was used to determine quercetin in the presence of 0.04 M phosphate buffer (pH ～4) containing 0.1 M KCl with 15 s accumulation time at 25±1°C. Under the optimal experimental conditions, the adsorbed form is oxidized irreversibly. The linear concentration ranged from 67.66 to 338.3 ppb quercetin. The detection limit of 6.77 ppb Q (r=0.9997), with 15 s accumulation time and the relative standard deviation of 0.45 (n=5) was calculated. The interferences of some metal ions and some amino acids were studied. The method was applied to the analysis of spiked urine, with recovery of 99.9±0.5, and the relative standard deviation of 3.2%. Results were compared with the reported methods.     

碳糊电极上吸附伏安法测定痕量钪的研究

研究了钪(Ⅲ) 茜素氨羧络合剂(ALC)络合物在碳糊电极正电位区的吸附伏安行为,利用该络合物产生的二次导数吸附氧化峰电流与钪浓度成正比测定钪。其线性范围为2.0×10-9～6.0×10-7mol/L;富集120s,检出限达1.0×10-9mol/L(S/N=3)。探讨了电极反应机理。在同一支电极同一表面上15次连续测定4.0×10-8mol/L的Sc(Ⅲ),方法的相对标准偏差为3.7%。该法用于矿石样品中钪的测定,结果满意。     

碳糊电极阳极吸附伏安法测定氧氟沙星

碳糊电极阳极吸附伏安法测定氧氟沙星;氧氟沙星; 阳极吸附伏安法; 碳糊电极     

Voltammetric Determination of Valaciclovir Using a Molecularly Imprinted Polymer Modified Carbon Paste Electrode

A molecularly imprinted polymer (MIP) was rationally synthesized with the aid of computer based studies. The computational studies were used to screen for the most suitable template to functional monomer molar ratio. Two functional monomers were involved in the study (methacrylic acid and 4‐vinylpyridine). Four MIP ratios were synthesized in accordance with the results of the computational studies and their performance was evaluated using equilibrium rebinding assays. The MIP with the best performance was used as an additive in carbon paste electrodes for the voltammetric determination of valaciclovir (VCV). Following the optimization of voltammetric parameters, a linear response was obtained in the range of 1.0x10⁻⁶–7.0x10⁻⁴ M with a limit of detection at 4.45x10⁻⁷ M. The MIP modified carbon paste electrode was successfully applied for the determination of VCV in pure solutions and dosage form.     

碳糊电极阳极溶出法测定单宁酸的研究

用碳糊电极阳极溶出法研究了单宁酸的测定方法。实验表明,在1.0 mol/LHCl介质中,富集120 s,单宁酸在0.65 V(vs.SCE)处出现阳极溶出峰,在5.0×10-7~6.0×10-5mol/L范围内,其峰电流的大小与单宁酸的浓度呈线性关系,相关系数为0.9991,检出限为1.0×10-7mol/L。该法灵敏度较高,操作简便,可用于啤酒中单宁酸的测定,平均回收率为99.8%。     

CTAB化学吸附修饰电极线性扫描伏安法直接测定苯酚

本文提出了以十六烷基三甲基溴化铵(CTAB)修饰碳糊电极直接测定苯酚的电化学方法。在pH=8.0的0.1mol·L-1磷酸盐缓冲溶液中,苯酚在+0.63V出现一个灵敏的氧化峰,其峰电流与苯酚浓度在4.0×10-7～5.0×10-5mol·L-1之间呈线性关系,检出限为5.0×10-8mol·L-1。本文对CTAB对苯酚氧化的增敏机理进行了探讨。该电极用于工业废水中苯酚的检测,取得了满意的结果。     

掺杂硒修饰碳糊电极伏安法测定对乙酰氨基酚

采用循环伏安法制备了掺杂硒修饰碳糊电极,用循环伏安法和差分脉冲伏安法研究了对乙酰氨基酚在掺杂硒修饰碳糊电极上的电化学行为,建立了掺杂硒修饰碳糊电极测定对乙酰氨基酚的电化学方法。在pH 4.6的0.1mol·L-1乙酸-乙酸钠缓冲溶液中,对乙酰氨基酚在+0.61V呈现一个灵敏的氧化峰。对乙酰氨基酚的浓度在6.0×10-7~1.5×10-4 mol·L-1范围内与其氧化峰电流呈线性关系,检出限(3s/k)为2.8×10-7 mol·L-1。方法用于药品中对乙酰氨基酚的测定,测定结果与药典法测定值相符,测定值的相对标准偏差(n=5)在2.1%~2.5%之间。