多壁碳纳米管-铋膜电极微分电位溶出法测定涂料中的铅

制备了嵌入式多壁碳纳米管膜玻璃碳电极,研究了铅在电极上的电位溶出行为,建立了嵌入式碳纳米管-铋复合膜电极测定铅的微分电位溶出分析法。结果表明:富集电位为-1.1 V,HAc-NaAc(pH=4.60)缓冲溶液中,峰高与铅浓度在0.1～20.0μg/L范围呈线性,检出限为0.5μg/L,对实际样品进行测定,相对标准偏差(RSD)值在3.8%～7.1%之间,回收率在95.2%～98.7%之间。     

铋膜电极微分脉冲溶出伏安法测定食用明胶中的铅

通过铋膜修饰的玻碳电极,建立了明胶中铅的差分脉冲溶出伏安分析法。结果表明,在pH=4.0的HAc-NaAc缓冲介质中,-1.0 V富集300 s后,溶出峰电流与Pb2+浓度在50~1 000μg/L范围内呈线性关系,相关系数r=0.995 6,在实际样品测量中,回收率在97.75%~104.79%,相对标准偏差为2.20%。     

铋膜电极差分脉冲溶出伏安法测定苯甲酸钠中的铅

通过铋膜修饰的玻碳电极,建立了苯甲酸钠中铅的差分脉冲溶出伏安分析法。实验结果表明,在pH 4.0的HAc-NaAc缓冲介质中,-1.1 V富集300 s后,溶出峰电流与Pb2 浓度在5-1 000μg/L范围内呈线性关系,相关系数r=0.995 6,在实际样品测量中,回收率在95.4%-103.5%之间,相对标准偏差为3.44%。     

1.5次微分阴极溶出伏安法测定水样中痕量硒(Ⅳ)

采用玻碳汞膜电极为极化电极 ,研究了痕量硒 (IV)在 0 .10mol/LHClO4与 0 .10mol/LKCl支持电解质中的 1.5次微分阴极溶出行为。线性范围 0 .2 0～ 1.0 0 μg/L ,相关系数 0 .9997。     

阳极溶出伏安法测定牙膏中的痕量铅

牙膏样品用HNO3-H2O2分解后,采用汞膜玻碳电极阳极溶出伏安法测定试样中的痕量铅。方法的回收率为96-106%,相对标准偏差为5.7%     

计时电位溶出法测定天麻中的痕量砷

以镀金玻碳电极为工作电极,计时电位溶出法测定天麻中的痕量砷。选择富集电位为-0.45V,溶出低液为3.0 mol/L的硝酸,在+0.14V电位处获得一灵敏的砷(Ⅲ)的二次微分电位溶出峰,且该溶出峰的峰高与砷的质量浓度在2.0～12.0μg/L范围内呈线性关系,方法的检出限(3S/N)为0.96μg/L。方法用于测定天麻中痕量砷的回收率为97.6%～102.4%,RSD为2.7%～3.1%。     

微波富集-铋膜电极微分电位溶出法快速测定水中痕量铅

研究了镀铋膜电极微分电位溶出分析法测定水中铅的方法,考察了该法测定铅的条件.结果表明,在HAc-NaAc介质中铅可在镀铋膜电极上得到灵敏的微分电位溶出峰,结合微波富集方法,检出限达0.003 mg/L,利用标准加入法对水样中痕量铅进行测定,避免了镀汞膜电极带来的健康与环境危害,结果较满意.     

Bi_2O_3-石墨烯修饰玻碳电极阳极溶出伏安法测定西洋参中的铅和镉

建立西洋参中药中重金属铅和镉含量的电化学测定方法,考察市售西洋参药材的重金属铅和镉的含量。采用Bi_2O_3-石墨烯材料修饰玻碳电极,建立了阳极溶出伏安法同时快速测定铅和镉的新方法。在10~190μg/L浓度范围内,Pb~(2+)和Cd~(2+)的溶出峰电流与Pb~(2+)和Cd~(2+)的浓度呈良好线性关系,r=0.9991/r=0.9983,回收率RSD5.00%(n=6);西洋参重金属铅和镉的含量分别为15.19、16.81μg/L。Bi_2O_3-石墨烯材料修饰玻碳电极的阳极溶出伏安法检测重金属铅和镉简便、灵敏,可用于西洋参中铅和镉的检测。     

ICP-MS法测定硬聚氯乙烯管材和管件中重金属的研究

采用感应耦合等离子体质谱(ICP-MS)法，对硬聚氯乙烯(PVC-U)饮水管材和管件中痕量重金属元素铅、镉、锡、汞进行了分析.研究了影响测量的各种因素，确定了实验的最佳测定条件。结果表明该方法的检出限为：Pb，0.0028μg/L；Cd，0.0025μg/L；Sn，0.0052μg/；Hg，0.0033μg/L；回收率为96.04％～97.20％，相对标准偏差(RSD)小于2.53％。该方法应用于硬聚氯乙烯饮水管材和管件中痕量铅、镉、锡、汞的测定，简便、快速、准确。     

石墨烯-纳米金修饰电极的制备及其对痕量铅(Ⅱ)的测定

通过一步电沉积技术在玻碳电极表面构建了石墨烯-纳米金复合材料。将该复合材料与铋膜相结合,采用阳极溶出伏安法实现了对Pb(II)的检测。通过SEM对制备的石墨烯-纳米金复合材料进行了微观结构表征。拉曼光谱及电化学研究表明,石墨烯-纳米金复合材料具有良好的导电性和大的比表面积,修饰电极的电化学信号得到较明显增强,同时促进了铋膜预富集铅的能力,对Pb(II)检测灵敏度高,检测范围宽。在最佳实验条件下,其对Pb(II)浓度的定量测定线性范围为1~220μg?L-1,R=0.9987,检出限为0.1μg?L-1(S/N=3)。实际样品中铅的测定结果表明,该方法简便、可靠,具有实际应用价值。     

Disposable screen-printed antimony film electrode modified with carbon nanotubes/ionic liquid for electrochemical stripping measurement

In this paper, two disposable screen-printed antimony film electrodes (SPSbFEs) modified with multi-walled carbon nanotubes (MWCNTs) and ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]BF₄), respectively for electrochemical stripping measurement are introduced. The modified screen-printed electrode substrate was prepared by homogeneously doping the attractive material into the graphite-based printing ink, and then an antimony film was in situ formed by simultaneously electrodepositing the antimony precursor with interesting analytes on the modified substrate. The electroanalytical performance of the modified SPSbFE for heavy metals based on the anodic stripping protocol was intensively evaluated. It was found that stripping voltammetric measurements of mercury (II) and lead (II) at the modified SPSbFEs resulted in good peaks with very low background contribution. In comparison with the bare SPSbFE, the modifications of both MWCNTs and [Bmim]BF₄ were demonstrated providing more sensitive responses. The results indicated that the SPSbFE modified with 4 wt% [Bmim]BF₄ exhibited well linear behavior in the mercury (II) concentration range from 20 to 140 μg/L (R² = 0.998) with a detection limit of 0.36 μg/L (S/N = 3) under a 120 s accumulation, and good repeatability with a relative standard deviation (RSD) of 4.16% (40 μg/L, n = 12). The proposed electrodes, as new styles of “mercury-free” electrodes, also exhibit encouraging properties for measurements of practical samples.     

微波消解-原子荧光光谱法检测水产品中的微量汞

以硫脲作为掩蔽剂,低浓度硼氢化钾为还原剂,建立了微波消解-氢化物原子荧光光谱法检测水产品中微量汞含量的方法。本方法线性范围为0.00~4.00μg/L,相关系数r2=0.999 6;检出限为0.021 9μg/L;相对标准偏差为0.89%~2.64%;回收率为91.3%~101.5%。此方法检出限低,灵敏度高,操作简便快捷,准确度高,线性范围宽,能够达到检测水产品中微量汞的要求,可广泛用于水产品中微量汞含量的检测。     

Direct mercury determination in natural waters by chronopotentiometric stripping analysis in macroelectrode process vessel

By using a specific electrochemical cell with a rotating glassy carbon process vessel as the working electrode, a significant enhancement of mercury determination comparing to commonly used disc electrodes of glassy carbon was achieved. Detection limit obtained for electrolysis time of 600 s was 0.1 ng dm^− 3 of Hg(II). The influence of the most important experimental factors of chronopotentiometric stripping analysis was investigated and the defined method was applied for mercury determination in different types of waters without any pretreatment. Methods accuracy was confirmed by analysing standard reference material. Obtained results showed that similar electrochemical systems can be proposed for continual or semicontinual monitoring of mercury content in different types of waters.     

聚ABSA/CR复合膜修饰电极的制备及应用

采用电化学聚合方法制备了聚对氨基苯磺酸(ABSA)/刚果红(CR)修饰玻碳电极,并通过电化学方法研究了多巴胺(DA)在该修饰电极上的电化学行为。在pH4.0的0.1 mol/L NaAc-HAc缓冲溶液中,该修饰电极对多巴胺的氧化具有明显的催化活性。多巴胺的浓度在1×10-7～2.5×10-4mol/L范围内,其电化学响应信号与多巴胺浓度呈线性关系,检测限达6.9×10-8mol/L(3倍噪音法)。用同样方法制作电极对DA平行测定七次,RSD为6.7%,说明聚ABSA-CR/GCE电极有良好的重现性。该方法可用于盐酸多巴胺注射液实际样品的检测。聚ABSA/CR复合膜修饰电极的制备及应用还未见文献报道。     

Preparation of dendritic bismuth film electrodes and their application for detection of trace Pb(Ⅱ)and Cd(Ⅱ)

In this paper,dendritic Bi film electrodes with porous structure had successfully been prepared on glassy carbon electrode using a constant current electrolysis method based on hydrogen bubble dynamic templates.The electrode prepared using a large applied current density showed an increased internal electroactive area and a significantly improved electrochemical performance.The analytical utility of the prepared dendritic Bi film electrodes for the determination of Pb(Ⅱ)and Cd(Ⅱ)in the range of 5–50 μg·L~(-1)were presented in combination with square wave stripping voltammetry in model solution.Compared with non-porous Bi film electrode,the dendritic Bi film electrode exhibited higher sensitivity and lower detection limit.The prepared Bi film electrode with dendritic structure was also successfully applied to real water sample analysis.     

分散液液微萃取-气相色谱分析尿碘含量

以过硫酸铵消解处理尿液,用丁酮衍生后以二硫化碳为微萃取剂,甲醇为分散剂,用分散液液微萃取技术提取尿中碘代丁酮,以气相色谱-电子捕获检测器分析,用外标法定量。尿碘的线性范围为10~300μg/L,相关系数r=0.999 5,检出限0.20μg/L;方法回收率达91.9%~97.7%,相对标准偏差为2.4%~z4.6%(n=6)。该方法操作简便、灵敏度高,适于尿碘批量快速分析。     

氢化物原子荧光光谱法测定海洋沉积物中砷和汞

本文研究了海洋沉积物样品前处理方法同时具有提取砷、汞以及仪器操作条件,载流酸度,还原剂对原子荧光强度的影响。本方法具有操作简单、快速、灵敏度高等优点,检出限砷为0.30μg/L,汞为0.05μg/L,相对标准偏差分别为1.5%~9.7%,1.2%~9.6%,回收率为92%~109%。     

基于Cu-Mg-Al三元类水滑石修饰玻碳电极对食品中亚硝酸根的检测

制备了Cu-Mg-Al三元类水滑石修饰玻碳电极,研究了亚硝酸根在修饰电极上的电化学行为,Cu-Mg-Al三元类水滑石对亚硝酸根的电化学氧化具有明显的催化活性,评估了溶液pH值、扫描速率和施加电位对亚硝酸盐电流响应的影响,计算了电机有效表面积和NO2-在修饰电极表面的吸附容量,并初步探讨了催化机理,在优化的实验条件下,该修饰电极对NO2-的测定线性范围为0.1~10.42μmol/L,检测限为0.08μmol/L(S/N=3)。将该传感器用于食品中亚硝酸根离子的测定,结果满意。