分析化学中的化学修饰碳糊电极

对化学修饰碳糊电极的发展原因、电极制备及性能、富集机理等方面以及近5年来在电化学分析中的发展和应用进行了评述。引用文献共73篇。     

PVC-碳糊电极的制备与应用

PVC-碳糊电极可有效地富集Cu^2 ；以杯芳烃为修饰剂的PVC-碳糊电极通过电化学方法可识别测定Ag^ 。     

嵌入式超薄化学修饰碳糊电极及抗坏血酸的电化学行为研究

以镍铬合金为基体,在其表面构建了嵌入式超薄邻啡口罗啉修饰碳糊电极,以扫描电镜表征电极形貌、电化学技术研究电极的电化学性质。该电极对抗坏血酸(AA)有灵敏的响应,在pH 2.0的B.R.缓冲溶液中,AA的氧化峰电流与其浓度在1.0×10-7~1.0×10-4mol/L范围内呈良好的线性关系,检出限为6.0×10-8mol/L。该电极可用于AA的电化学测量。     

还原菌修饰碳糊电极研究及对微量金的测定

研究用细菌修饰的碳糊电极对金离子的响应特性，并应用该电极检测水溶液中的金离子，金离子家度在１０－１００μｇ／ｍＬ。呈线性关系，重现性为３．４％，检测限达１ｎｇ／ｍＬ，电极具有制备简单，灵敏诬高等优点。文中还讨论了金离子在还原菌修饰的碳糊电极上的还原机理。     

丁二酮肟化学修饰碳糊电极测定微量钯

报道了丁二酮肟化学修饰碳糊电极用于测定微量钯的研究。实验表明，Pd（Ⅱ）浓度在1×10－4～5×10－7mol·L－1范围内呈良好的线性关系。对模拟样进行了测定。     

碳糊电极在有机物电化学分析中的应用

碳糊电极作为一种制备简单、易于更新和重现性好的新型电极，在有机物分析中应用非常广泛。本文就从电极材料的选择、修饰剂的选用和有机物分类等几个方面对近几年碳糊电极在有机物电化学分析上的进展进行评述。引用文献54篇。     

β-环糊精修饰碳糊电极测定盐酸青藤碱

研究盐酸青藤碱在β-环糊精(β-CD)修饰碳糊电极上的电化学行为,在此基础上建立了测定盐酸青藤碱的电化学新方法。盐酸青藤碱在β-CD修饰碳糊电极上是受吸附控制的电化学反应过程,在p H 6.6的柠檬酸–柠檬酸钠底液中,盐酸青藤碱在β-CD修饰碳糊电极上产生一对良好的氧化还原峰,峰电位分别为0.458 V和0.086 V。氧化峰电流与盐酸青藤碱的质量浓度在3.658 5~91.462 5 mg/L范围内呈良好线性关系,线性相关系数为0.995 4,检出限为1.229 3 mg/L。该方法应用于正清风痛宁片中盐酸青藤碱含量的测定,测定结果的相对标准偏差为5.82%(n=7),回收率在95.7%~107.4%之间。该方法简便、快速,结果准确,可用于盐酸青藤碱的测定。     

18—冠—6修饰碳糊电极测定定金的研究

本文研究了１８－冠－６修饰碳糊电极测定金的条件，金在０．５ｍｏｌ／Ｌ ＨＣｌ－０．００５ｍｏｌ／Ｌ ＫＣｌ底液中富集，介质交换到０．０１ｍｏｌ／Ｌ ＨＣｌ中进行测定。金（Ⅲ）浓度在０．１～１．０μｇ／ｍＬ范围内呈线性关系，相对标准偏差为９．７％，检出限为２０ｎｇ／ｍＬ。可不经预先分离直接测定矿样中的金，结果良好。并研究了Ａｕ（Ⅲ）在１８－冠－６碳糊修饰电极上的还原机理。     

NO-2的芯片毛细管电泳-修饰碳糊电极电化学检测

制备了3-巯丙基三甲氧基硅烷-铜(MPTMS-Cu)/MCM-41分子筛修饰碳糊电极,研究了该修饰电极对NO-2电化学还原的 电催化作用,分析了修饰物含量、溶液pH对电化学反应的影响。以该电极为检测电极,设计制作了芯片毛细管电泳-电化学 检测系统,探讨了NO-2的芯片毛细管电泳检测方法。以50 mmol/L醋酸钠(pH 5.8)为电泳缓冲液、分离电压为-1.6　kV时 ,检测可在40 s内完成。纯水中NO-2检测的线性浓度范围为10.0～5000.0 μmol/L,检出限为4.0 μmol/L。     

锂皂石修饰碳糊电极测定痕量铜的研究

报道了锂皂石修饰碳糊电极测定痕量铜，在含０．００１ｍｏｌ／Ｌ ＫＣｌ Ｃｕ＾＋２的试液中，开路富集后介质交换到０．０５ｍｏｌ／Ｌ ＫＣｌ中，用微分脉冲伏安法测定，检测限为７．０ｎｇ／ｍＬ。常见阳离子基本不干扰，可不经预先分离直接测定精金矿中铜的含量，结果良好。还探讨了Ｃｕ＾＋２在锂皂石修饰碳糊电极上的反应机理。     

谷胱甘肽在高岭土修饰碳糊电极上的电化学研究

制备了高岭土修饰碳糊电极(KCPE),并以氢醌(HQ)为电催化介质测定还原型谷胱甘肽(GSH)。实验结果表明,在该电极上谷胱甘肽(GSH)的加入对氢醌的电化学响应有明显提高,且电催化氧化峰电流与GSH浓度呈良好的线性关系,由此可采用差分脉冲伏安法(DPV)对GSH进行定量测定。对修饰电极的电化学性能进行了表征,测得电极有效表面积为0.118 6 cm2、电荷传递系数为0.68、表观速率常数为1.08×104cm3·mol-1·s-1。在优化条件下,测得GSH在KCPE上的线性范围为0.1~1,2.5~25μmol/L,检出限为0.073μmol/L。用该方法对含GSH的市售药进行测定,结果满意。     

TBP碳糊修饰电极三元络合物体系测定痕量铅（Ⅱ）

研制了磷酸三丁酯（ＴＢＰ）碳糊修饰电极，在含１－苯基－３－甲基－４－苯甲酰基－５－吡唑酮（ＰＭＢＰ）的ＨＣｌ－ＫＣｌ底液中，通过电位富集，将三元络合物Ｐｂ（ＰＭＢＰ）２（ＴＢＰ）２中的铅富集在电极上，用２．５次微分阳极溶出伏安法测定铅．铅浓度在１．０×１０－９～２．５×１０－７ｍｏｌ·Ｌ－１范围内与峰高呈良好的线性关系．该电极用于铜合金和废水中铅的测定，获得满意结果．     

ssDNA/十八酸修饰碳糊电极的制备及伏安法表征

将石墨粉与十八酸在80 ℃下混合制成表面富含—COOH的基底碳糊电极(SA/CPE), 然后在活化剂N-羟基琥珀酰亚胺(NHS)和1-乙基-3-(3-二甲基氨丙基)碳二亚胺盐酸盐(EDC)存在下将ssDNA固定到电极表面制备ssDNA修饰电极(ssDNA/SA/CPE). 以亚甲基蓝(MB)为指示剂, 用循环伏安法对SA/CPE和ssDNA/SA/CPE进行电化学表征, 发现其在ssDNA/SA/CPE上较在SA/CPE上的氧化峰电流(i_pa)和还原峰电流(i_pc)分别增大1.9倍和1.7倍, 式电势(E_f)负移8 mV. 把ssDNA/SA/CPE放在互补ssDNA溶液中杂交后, MB的i_pa 和i_pc较在SA/CPE上分别增大1.0倍和0.8倍, E_f负移18 mV. 用0.5 mol/L 的NaOH溶液冲洗使电极表面杂交而成的dsDNA变性洗脱, MB的伏安信号几乎与在ssDNA/SA/CPE上一样. i_pc与SA/CPE上固定的ssDNA质量在1.0×10^－7～5.0×10^－6 g范围内成线性关系, 检测限为2.0×10^－9 g (S/N＝3). 这种既廉价又灵敏的电化学生物传感器有望在转基因植物产品检测研究中得到应用.     

蒙脱石修饰碳糊电极测定苯酚的研究

本文报道蒙脱石修饰碳糊电极在醋酸盐缓冲溶液(pH=3.6)中,用微分脉冲伏安法测定苯酚。在+0.90 V(vs.Ag/AgCl)有一灵敏的氧化峰,伏安响应要比碳糊电极高得多.对测定苯酚的条件进行了研究,苯酚在0.1～1.0μg/ml范围内呈线性,检出限为40ng/ml,相对标准偏差为6.7％,平均回收率为97.2％。用此方法,不经分离直接测定饮料中的酚。还对苯酚在蒙脱石修饰碳糊电极上的反应机理进行了探讨。     

8—羟基喹啉合镁碳糊修饰电极的研究

本文研制了８－羟基喹啉合镁碳糊修饰电极，并研究了电极性能，实验发现，该修饰电极具有类化学传感器的特性，电极在一定条件下对Ｍｇ＾２＋离子有类能斯特响应，电极用于试样分析取得成功。     

Voltammetric Determination of an Anti-rheumatoid Drug Acemetacin on Graphite Flake Paste Electrode and Glassy Carbon Electrode

In this study, a simple and sensitive square wave voltammetric procedure has been developed for the determination of acemetacin (ACM) at graphite flake paste electrode (GFPE) and glassy carbon electrode (GCE). Under optimized conditions, the dependence of ACM peak current on its concentration showed wide linear range: 0.03–1.0 μmol L⁻¹ and 0.7–15.0 μmol L⁻¹ at GFPE and GCE, respectively. The developed method was successfully applied for the determination of ACM in pharmaceuticals and spiked urine with satisfying recoveries. The electrochemical oxidation of ACM is an irreversible process controlled by mixed nature of the mass transfer process.     

Carbon Paste Electrode Modified with Biochar for Sensitive Electrochemical Determination of Paraquat

The present work reports for the first time the determination of paraquat (PQ²⁺) by Differential Pulse Adsorptive Stripping Voltammetry (DPAdSV) using a carbon paste electrode modified (CPME) with biochar obtained from castor oil cake at different temperatures (200–600 °C). The best voltammetric response was verified using biochar yielded at 400 °C (CPME‐BC400). Linear dynamic range (LDR) for PQ²⁺ concentrations between 3.0×10^?8 and 1.0×10^?6 mol L^?1 and a limit of detection (LOD) of 7.5×10^?9 mol L^?1 were verified. The method was successfully applied for PQ²⁺ quantification in spiked samples of natural water and coconut water.     

Differential Pulse Adsorptive Stripping Voltammetric Determination of Chlorpyrifos at a Sepiolite Modified Carbon Paste Electrode

Abstract

An adsorptive stripping voltammetric (AdSV) method for the determination of organophosphorus insecticide chlorpyrifos at a bare carbon paste electrode (CPE) and clay modified carbon paste electrode (CMCPE) was developed. A systematic study of various experimental conditions, such as the pH, accumulation variables and composition of a modifier on the adsorptive stripping response, were examined by using differential pulse voltammetry. A significant improvement was observed in the sensitivity by using the present method with CMCPE. When CMCPE was used, a linear response was obtained over the concentration range 0.0001–2.0 ppm with lower detection limit of 0.00008 ppm, at an accumulation time of 80 s. The interference from other herbicides and ions on the stripping signal of the compound was also evaluated. The described method was applied to estimate the chlorpyrifos in environmental samples.     

Chemically Modified Carbon Paste Electrode for Determination of Sulfate Ion by Potentiometric Method

Four Schiff base complexes of different metal ions, M=Cr(III), Mn(III), Fe(III), and Co(III), were studied to characterize their ability as sulfate ion carriers in carbon paste electrode (CPE). The modified CPE electrode with Schiff base complex of Cr(III), N,N′‐ethylenebis(5‐hydroxysalicylideneiminato) chromium(III) Chloride, showed good response characteristics to SO₄^2? ion. The proposed electrode exhibits a Nernstian slope of 28.9±0.4 mV per decade for SO₄^2? ion over a wide concentration range from 1.5×10^?6?4.8×10^?2 M, with a detection limit of 9.0×10^?7 M. The CPE electrode manifested advantages of relatively fast response time, suitable reproducibility and life time and, most important, good potentiometric selectivity relative to a wide variety of other common inorganic anions. The potentiometric response of the electrode is independent of the pH of the test solution in the pH range 4.0–9.0. The proposed electrode was used as an indicator electrode in potentiometric titration of sulfate with Ba²⁺ ion, the determination of zinc in zinc sulfate tablet and also determination of sulfate content of a mineral water sample.