聚L-苏氨酸铅笔芯修饰电极对盐酸异丙嗪的电化学行为及测定研究

通过循环伏安法(CV法)在铅笔芯电极上成功地制备了聚L-苏氨酸修饰膜,研究了铅笔芯修饰电极上的最佳聚合条件,并对电极的表面结构进行显微表征.同时,研究了盐酸异丙嗪在该修饰电极上的电化学行为.由盐酸异丙嗪在聚L-苏氨酸修饰电极上的氧化和高锰酸钾在金电极上的还原组成双安培检测体系,建立了在外加电压为0V条件下流动注射双安培法直接测定盐酸异丙嗪的新方法.在pH6.8PBS(磷酸盐缓冲溶液)中,该氧化峰峰电流与盐酸异丙嗪浓度在2.0×10-6～1.5×10-3mol/L范围内呈线性关系(r=0.9979,n=12),线性回归方程为I(nA)=1.97×107c-300,方法检出限为8.5×10-7mol/L(S/N=3).RSD为1.60%(n=20),进样频率为100样/h.     

对乙酰氨基酚在多壁碳纳米管修饰电极上的电化学行为

制备了多壁碳纳米管修饰玻碳电极,研究了对乙酰氨基酚在多壁碳纳米管修饰电极上的循环伏安行为,并建立了测定对乙酰氨基酚含量的电化学分析方法。在pH为6.89的磷酸盐缓冲液中,多壁碳纳米管修饰电极对对乙酰氨基酚有明显的电催化作用,其氧化峰电流与对乙酰氨基酚浓度在1.0×10-6～1.0×10-4mol·L-1范围内呈良好的线性关系,检测限为2.0×10-7mol·L-1。     

对乙酰氨基酚在多壁碳纳米管L-半胱氨酸共组装修饰金电极上的电化学行为研究及其测定

在N,N-二环已基碳酰亚胺(DCC)存在介质下,通过酰氨键使羧基化的多壁碳纳米管(MCNTs)与L-半胱氨酸(L-Cys)缩合,功能化的MCNTs通过S Au键自组装(SAM s)到金电极表面,制备了修饰电极(MCNTs-L-Cys-Au/SAM s-CME),并对电极的表面结构进行电化学表征。研究表明,该修饰电极对对乙酰氨基酚的电化学氧化具有明显的催化作用。同时,对其催化氧化的机理进行了初步探讨。将此修饰电极用于流动注射不可逆双安培(FI-IB)体系的构建,即利用对乙酰氨基酚在MCNTs-L-Cys-Au/SAM s-CME上的氧化和KMnO4在另一支铂电极上的还原构建了双安培检测体系,成功的建立了在外加电压为0 V条件下流动注射双安培法直接测定对乙酰氨基酚的新方法。在0 V外加电压下,在0.05 mol/L硫酸载液中,该氧化峰峰电流与对乙酰氨基酚浓度在2.0×10-6~2.0×10-4mol/L范围内呈良好的线性关系,其线性回归方程为i(nA)=8.21×107C 200(r=0.9984,n=9);在2.0×10-4~1.0×10-3mol/L范围内呈线性关系,其线性回归方程为i(nA)=2.30×107C 104(r=0.9938,n=4),方法检出限为1.0×10-6mol/L(S/N=3);连续测定1.00×10-4mol/L对乙酰氨基酚标准溶液20次,电流值RSD为2.7%,进样频率为90样/h。该方法具有较高的选择性和灵敏度。对乙酰氨基酚片中的对乙酰氨基酚的含量的测定,结果比较满意。     

盐酸左氧氟沙星在聚L-精氨酸/多壁碳纳米管修饰电极上的电化学行为

运用循环伏安法、线性扫描伏安法、计时电量法等研究了盐酸左氧氟沙星在聚L-精氨酸/多壁碳纳米管修饰电极上的电化学行为。实验表明:盐酸左氧氟沙星在聚L-精氨酸/多壁碳纳米管修饰电极上的电极反应过程为等电子等质子吸附控制的不可逆过程,在pH=6.0的Na2HPO4-NaH2PO4支持电解质中,其氧化峰电流与浓度在7.0×10-6~1.0×10-4mol·L-1范围内呈良好的线性关系,相关系数R为-0.9992,检出限为5.0×10-6mol·L-1,样品测定回收率为98.26%~101.70%。     

盐酸氯丙嗪-联吡啶钌体系在多壁碳纳米管修饰电极上的电化学发光行为研究及盐酸氯丙嗪的测定

在玻碳电极上成功制备了多壁碳纳米管修饰电极(MWCNTs/GCE),优化了该修饰电极的制备条件.研究了联吡啶钌和盐酸氯丙嗪在该修饰电极上的电化学行为和电化学发光行为,建立了电化学发光法测定尿液中盐酸氯丙嗪的分析方法.结果表明,联吡啶钌-氯丙嗪体系在MWCNTs/GCE上表现出很好的电化学活性和电致化学发光响应,多壁碳纳米管不但增大了玻碳电极的比表面积而且加快了联吡啶钌在电极表面的电化学氧化,对联吡啶钌的电化学发光强度具有明显的增敏作用,同时盐酸氯丙嗪对联吡啶钌在该修饰电极上的电致化学发光具有很强的增敏作用.在0.1 mol/L的磷酸盐(pH 7.5)缓冲溶液中,盐酸氯丙嗪在该修饰电极上的检出限(S/N=3)为6.0×10-7 mol/L,在1.0×10-6 ～4.0×10-4 mol/L范围内浓度与相对发光强度呈线性关系(r=0.995 2).连续测定6.0×10-5 mol/L的盐酸氯丙嗪溶液13次,发光强度的RSD值为2.50%,表明该修饰电极具有较好的重复性.该方法已经成功地应用于尿样的检测.     

多壁碳纳米管修饰电极检测盐酸氯丙嗪的研究

制备了多壁碳纳米管修饰玻碳电极,采用循环伏安法(CV)研究了盐酸氯丙嗪在修饰电极上的电化学特性,发展了一种新的检测盐酸氯丙嗪的电化学分析方法。在最佳实验条件下,用循环伏安法检测盐酸氯丙嗪,其响应电流与盐酸氯丙嗪的浓度在8.0×10-5~1.0×10-3mol/L范围内有很好的线性关系,线性方程为Ip(A)=0.0106c(mol/L)-8×10-8(R2=0.999,n=6),检出限为6.2×10-6mol/L(S/N=3)。方法可用于盐酸氯丙嗪片的测定。     

聚对氨基苯磺酸修饰玻碳电极不可逆双安培法测定酪氨酸

在玻碳电极上成功地制备了聚对氨基苯磺酸修饰电极(P-p-ABSA/GCE),研究了酪氨酸在该修饰电极上的电化学行为.将此修饰电极用于流动注射不可逆双安培体系的构建,建立了流动注射双安培法直接测定酪氨酸的方法.在0 V外加电压下,在0.005 mol/L硫酸载液中,酪氨酸的氧化峰峰电流与其浓度在2.0×10-6 ～2.0×10-4 mol/L范围内呈良好的线性关系,方法的检出限(S/N=3)为1.0×10-7 mol/L.连续测定1.00×10-5 mol/L的酪氨酸标准溶液,电流值的相对标准偏差(RSD)为1.48%(n=20).该方法具有较高的选择性和灵敏度,应用于测定复方氨基酸注射液中酪氨酸的含量的测定,结果比较满意.     

氯丙嗪在离子液体BMIMPF6修饰玻碳电极上的伏安行为

对氯丙嗪(CPZ)在离子液体BMIMPF6修饰玻碳电极(BMIMPF6/GC)上的伏安行为进行了研究.发现CPZ在该修饰电极上于065V左右产生氧化还原峰,峰的可逆性比玻碳电极(GC)有较大改进,其电极过程为吸附控制.在0050 mol/L磷酸缓冲溶液(pH 4)中,CPZ在BMIMPF6/GC上的氧化峰的峰电流约为GC上的2倍.在优化实验条件的基础上,采用微分脉冲伏安法对不同浓度CPZ溶液进行了测定.结果表明,CPZ在BMIMPF6/GC上的氧化峰电流与浓度在56×10-9～30 ×10-5mol/L范围内有线性关系.将此方法用于尿样的测定,其加入回收率为97％左右.用3种电极测定了CPZ的表观扩散系数,其大小为D(BMIMPF6/GC)＞DOMIMBF6/GC)＞D(GC),这与电极表面积变化及膜内扩散有一定关系.     

磺胺在碳纳米管修饰玻碳电极上的电化学行为

磺胺类抗菌药是一类允许在饲料中添加的兽用广谱抗菌药.它被广泛用于治疗家畜呼吸道、消化道细菌感染、猪萎缩性鼻炎、禽霍乱、伤寒等疾病[1].停药期用药或用药不当将导致动物食品中抗菌药残留超标.人们长期食用含磺胺类抗菌药残留超标的动物产品,将导致肝肾损伤和体内耐药菌株产生,危害到人们的身体健康和疾病治疗.     

氧氟沙星在聚L-色氨酸修饰电极上的电化学行为及测定

氧氟沙星(ofloxacin,OFL)又名氟嗪酸,是第3代喹诺酮类药物,通过作用于细胞DNA螺旋酶的A亚单位,抑制DNA的合成和复制导致细菌死亡,具有高效广谱抗菌作用,是治疗呼吸道、泌尿道、肠道、皮肤、关节及软组织等感染的有效药物,而大剂量的服用可发生结晶尿,若不调整剂量,会使肝、肾功能减退、血药浓度增高等,因此测定药物中OFL的含量有重要意义.     

Electrochemical study of bergenin on a poly(4-(2-pyridylazo)-resorcinol) modified glassy carbon electrode and its determination in tablets and urine

A very sensitive electroanalytical method was employed to determine bergenin in phosphate buffer with a pH of 6.0, bergenin was accumulated at a 4-(2-pyridylazo)-resorcinol (PAR) polymer film modified glassy carbon electrode (GCE) surface under the condition of open-circuit. In the following anodic sweep from −0.4 to 0.8 V, bergenin adsorbed at the PAR polymer film modified electrode surface, was oxidized and yielded a sensitive oxidation peak at 0.595 V. Due to its unique structure and extraordinary properties, the PAR polymer film shows higher accumulation efficiency toward bergenin compared with a bare GCE. Hence, the amount of bergenin at the PAR polymer film modified GCE surface increases significantly, and finally the oxidation peak current improves greatly. The experimental conditions, such as supporting electrolyte, pH value, accumulation time and scan rate, were optimized for the measurement of bergenin, and a sensitive electroanalytical method was proposed for bergenin determination. The oxidation peak current varies linearly with the concentration of bergenin over the range of 2.0 × 10⁻⁷ to 1.2 × 10⁻⁵ mol/L, and the detection limit is 2.0 × 10⁻⁸ mol/L after 3 min open-circuit accumulation. The relative standard deviation of the same electrode in 10 successive scans is 1.8% for 1.0 × 10⁻⁶ mol/L bergenin and 2.1% for interelectrodes, indicating excellent reproducibility. This new method was successfully demonstrated with bergenin tablets and diluted urine.     

肾上腺素在聚L-半胱氨酸修饰玻碳电极上的电化学行为

利用循环伏安法制备了聚L-半胱氨酸修饰电极,研究了肾上腺素在该修饰电极上的电化学行为。在pH 7.0磷酸盐缓冲溶液中,肾上腺素氧化峰电流与其浓度在6.0×10-7~1.0×10-4mol/L范围内呈良好的线性关系,检出限(信噪比=3)为8.6×10-8mol/L。实验结果表明该电极具有良好的重现性、稳定性,已用于注射液中肾上腺素的检测。     

对乙酰氨基酚在石墨烯/壳聚糖复合膜修饰电极上的电化学行为研究

制备了石墨烯-壳聚糖复合物修饰玻碳电极(GO/CS-GCE),考察了对乙酰氨基酚(APAP)在修饰电极上的电化学行为,发现石墨烯-壳聚糖复合物能较好改善玻碳电极对APAP的电化学性能,APAP在修饰电极上的电化学反应过程是受吸附控制的2电子,2质子反应过程;进一步研究发现在pH=9.16的碳酸钠-碳酸氢钠缓冲体系中,对...     

芦丁在Au-TiO_2修饰电极上的电化学行为及其测定

利用沉淀沉积法合成了纳米金-二氧化钛(Au-TiO_2)复合纳米材料.构建了Au-TiO_2复合材料修饰的电化学传感器,并对芦丁进行了检测.通过扫描电镜(SEM),X射线衍射(XRD)对Au-TiO_2复合材料进行表征,利用循环伏安(CV)和电流时间曲线(Amperometric i-t Curve)考察了其对芦丁的电催化性能.在最优条件下对芦丁进行检测,检测范围为0.1~10μmol/L,灵敏度为1.47μA·μmol·L~(-1)·cm~(-2),信噪比为3时检测限为0.083μmol/L.     

Electrochemical determination of mesotrione and its degradation products on glassy carbon electrode

A simple, fast and sensitive analytical method was developed for the quantification of herbicide mesotrione (MES) and its degradation products: 4-(methylsulfonyl)-2-nitrobenzoic acid (MNBA) and 2-amino-4-(methylsulfonyl) benzoic acid (AMBA) using differential pulse voltammetry (DPV). Voltammetric measurements were performed using glassy carbon electrode (GCE). Potential range, pH of the electrolyte and the scan rate were optimised to achieve the lowest detection limits of analytes. The optimal conditions were obtained in a Britton–Robinson (BR) buffer at pH 4.0 for MNBA and at pH 6.0 for MES and AMBA, with the scan rate 0.08 V/s. The potential V for (1) nitro and carbonyl groups of MES, (2) nitro group of MNBA and (3) amino group of AMBA, obtained under optimised conditions, was plotted as a function of a peak current (I). The I(V) dependencies were measured for the following concentration ranges: 0.5–5.0 µM for the nitro group of MES and MNBA, 0.75–5.0 µM and 0.50–8.5 µM for the carbonyl groups of MES, and 0.25–8.5 µM for amino group of AMBA; whereas, the limit of detection was in range 0.07–0.23 µM (20–80 µg/L). The proposed method is the first one that allows the determination of both MES and its degradation products. The practical applicability of these newly developed voltammetric methods was verified by direct determination of MES and its degradation products in model samples of drinking and surface water.     

对乙酰氨基酚在离子液体修饰碳糊电极上的电化学行为及其测定

用亲水性离子液体1-丁基-3-甲基咪唑四氟硼酸作修饰剂制备了离子液体修饰碳糊电极(IL/CPE).在pH4.78的Britton-Robinison缓冲溶液中,用循环伏安法和方波伏安法研究了对乙酰氨基酚在IL/CPE上的电化学行为.研究表明,IL/CPE对对乙酰氨基酚的氧化还原反应有良好的电催化作用.在方波伏安曲线上,对乙酰氨基酚的氧化电流与其浓度在8.0×10<'-7>～2.0×10<'-4>mol/L范围内呈线性关系,检出限为3.0×10<'-7>mol/L(S/N=3).建立了测定片剂中对乙酰氨基酚含量的新方法.     

Sensitive determination of adenine on poly(amidosulfonic acid)-modified glassy carbon electrode

A novel and reliable direct electrochemical method was established for the detection of adenine, based on the differential pulse anodic stripping response at a poly(amidosulfonic acid) (poly-ASA)-modified glassy carbon electrode (GCE) fabricated by electropolymerization. The characterization of electrochemically synthesized poly-ASA film was investigated by atomic force microscopy, electrochemical impedance spectroscopy, and voltammetric methods. This poly-ASA-modified GCE could greatly enhance the detection sensitivity of adenine. At optimum conditions, the anodic peak exhibits a good linear concentration dependence in the range from 3.0 × 10⁻⁸ to 1.0 × 10⁻⁶ M (r = 0.9994). The detection limit is 8.0 × 10⁻⁹ M (S/N = 3). The proposed method could be used to determinate the adenine in tablets of vitamin B₄ with satisfactory results.     

Electrochemical behavior of C-(60) modified electrode in aqueous solutions

The construction of adsorptive type C60 modified electrode and its electrochemical reduction and oxidation behavior in aqueous solutions are described in this report. Four pairs of one-electron transfer reduction and oxidation cyclic voltammetry is obtained in aqueous solution containing 30% CH3CN and 2% (C2H5)4NOH. It is reported in this paper that the C60 modified electrode also catalyzes the electrochemical reduction of dissolved oxygen in 40% DMF and 2% (C2H5)4NOH aqueous solution and this might open a new field for the potential applications of C60 in electrochemistry and electroaualytical chemistry.     

聚5-磺基水杨酸修饰电极上对苯二酚的电化学行为

用循环伏安法将 5 磺基水杨酸修饰于玻碳电极表面 ,制备出对对苯二酚具有电催化作用的聚合物膜修饰电极。研究了对苯二酚 (HQ)在该聚合物薄膜修饰电极上的电化学行为。在 0 5mmol/LH2 SO4底液中 ,HQ在该电极上的线性范围为 2 0× 1 0 - 6～ 1 0× 1 0 - 4 mol/L。该修饰电极可将对苯二酚和邻苯二酚(CC)的氧化峰分开约 1 0 5mV