偏最小二乘-分光光度法同时测定福美锌和代森锰农药残留量

利用紫外可见分光光度法研究了农药福美锌和代森锰与苯基荧光酮的相互作用,发现反应后的产物分别在波长为551和554 nm处最大有吸收,但光谱严重重叠.实验采集了450～700 nm波长范围吸光度数据,并对该数据进行一阶求导后用偏最小二乘法处理,据此建立了偏最小二乘-分光光度法同时测定福美锌和代森锰两种农药的新方法.福美锌和代森锰的线性范围分别为0.3～6.0和0.2～3.5 μg/mL;检出限分别为0.22和0.13 μg/mL.混合样品分析无需分离,方法简单、快速.用于水果、大米和自来水等实际样品测定.     

偏最小二乘法在多组分阳极溶出伏安分析中的应用—铜,锑,铋的同时测定

本文利用微分脉冲阳极溶出伏安法对微量铜、锑、铋混合溶液进行同进分析，实验在盐酸－氯化钠介质中进行，悬汞电极作工作电极，在－４００ｍＶ处富集电解５ｍｉｎ，然后由－４００ｍＶ向０Ｖ作微分脉冲溶出伏安扫描，扫描速度为２ｍＶ／ｓ，脉冲振幅为４０ｍＶ，由于计算机采集溶出伏安数据后采用偏最小二乘法计算并建立数学模型，然后据此模型对未知溶液进行定量分析，获得了较好的结果。     

微分脉冲溶出伏安法测定除草通

提出了苹果、土豆、西红柿中除草通残留量的电分析化学测定方法,研究了除草通在汞电极上的电化学行为,探讨了其电极反应机理。结果表明,除草通在汞电极上具有吸附性质,其电极反应为不可逆的还原过程。本方法的测量线性范围为0．01～0．16mg/L,检出限为9．1μg/L.     

微分脉冲阳极溶出伏安法对吡虫啉的测定研究

应用循环伏安法和微分脉冲阳极溶出伏安法在玻碳电极上(GCE)对吡虫啉进行了研究,发现吡虫啉(C=5.0×10-4mol/L)在pH 2.0的B-R(Britton-Robinson)缓冲底液中于 0.986 V(vs.SCE)左右产生一个尖锐的阳极氧化峰。本文讨论了pH、富集时间、扫速、静止时间的影响。吡虫啉在2.0×10-5~4.0×10-4mol/L范围内与峰电流呈线性关系(r=0.9986),检出限为1.0×10-6mol/L。用该方法对吡虫啉进行了实际测定,还对吡虫啉的电极反应机理进行了初步探讨。     

微分脉冲阴极吸附溶出伏安法测定利多卡因

用微分脉冲阴极吸附溶出伏安法测定了利多卡因针剂的含量。浓度与波高的线性范围为1×10~(-7)～3×10~(-4)mol/dm~3。最低检测限l×10~(-8)mol/dm~3。回收率98.07±0.05%。     

微分脉冲阴极溶出伏安法测定阿米卡星

硫酸阿米卡星(Am ikacin sulfate)是一种氨基糖苷酸类抗生素,化学名为O-3氨基-3-脱氧-а-D-蒲吡喃糖基-(1-6)-O-[6-氨基-6-脱氧-а-D-蒲吡喃糖基-(1-4)]-N-(4-氨基-2-羟基-1-氧丁基)-2-脱氧?D-链霉胺硫酸盐。目前报道的测定方法主要有高效液相法[1]、镍毛细管电泳法[2]。本文研究了阿米卡星在玻碳电极上的电化学行为。微分脉冲溶出伏安法是一种灵敏度很高的痕量分析方法,本文利用该方法对阿米卡星进行了测定,发现阿米卡星在pH=2的盐酸底液中,产生一灵敏的还原峰,可用于定量测定。平行测定了7次,RSD为2·05%,该方法可用于注射液及血清中…     

核黄素的微分脉冲溶出伏安分析

采用循环伏安法和微分脉冲溶出伏安法,对核黄素在裸金电极和巯基化合物分子自组装膜修饰金电极上的电化学行为进行了研究,发现在pH4.8的B-R缓冲溶液中,核黄素在裸金电极和分子自组装膜修饰金电极上均于-0.35V左右产生一对可逆的氧化还原峰。核黄素在裸金电极和谷胱甘肽、三巯基丙酸、二巯基苯丙咪唑分子自组装膜修饰金电极上,其浓度分别在3.0×10-7～2.3×10-4mol/L、1.05×10-6～2.0×10-4mol/L、2.1×10-6～2.08×10-4mol/L、1.05×10-6～2.0×10-4mol/L范围内与微分脉冲伏安峰峰电流之间有良好的线性关系,其相关系数分别为0.9932、0.9909、0.9857、0.9832,核黄素的检出限为2.1×10-7mol/L、5.2×10-7mol/L、8.6×10-7mol/L、5.2×10-7mol/L。对浓度为1.0×10-5mol/L的核黄素进行10次平行测定,所得峰电流的相对标准偏差为2.0%。将该方法用于核黄素片剂和复合维生素B片剂的测定,结果令人满意。     

微分脉冲溶出伏安法测定五氯硝基苯

研究五氯硝基苯的电化学性质,利用循环伏安法(CV)对五氯硝基苯标准溶液初步扫描,得到一组可逆的氧化还原峰,峰电位分别为100 mV与153 mV(vs.Ag/AgCl).其线性范围为3.0×10-6～1.0×10-4 moL/L(r=0.9993),检出限为2.6×10-7～moL/L.用该方法测定了白菜、土壤及土壤水样中的五氯硝基苯样品,平均加标回收率为92.0%～109.7%,RSD不大于3%(n=5).初步探讨了五氯硝基苯的电极反应机理.     

微分脉冲溶出伏安法测定2,4-二硝基-1-萘酚

以Britton-Robinson(pH=8.0)缓冲液为底液,富集电位为-0.05V,富集时间为30s,电位扫描速率20mV/s,产生2个完全分离的峰,在-0.58±0.01V(vs.Ag/AgCl)处产生的峰灵敏度高且峰形好,故以此峰为定量峰。2,4_二硝基_1_萘酚浓度在6.00×10-8～2.00×10-6mol/L时与峰电流呈良好的线性关系,线性相关系数为0.9996。检出限为4.00×10-9mol/L,信噪比S/N约为10。     

微分脉冲溶出伏安法结合化学计量学测定醚类除草剂

在pH=6.82的Britton-Robinson缓冲溶液中,采用循环伏安法和微分脉冲溶出伏安法对醚类除草剂甲羧除草醚(Bifenox)和三氟羧草醚(Acifluofen)的伏安行为进行了研究,发现吸附时间为50 s时此电化学体系达到平衡,而且微分脉冲溶出伏安法能给出较高的灵敏度,甲羧除草醚和三氟羧草醚分别在-685 mV和-700 mV处具有良好还原峰,但由于峰电位接近而谱峰重叠,很难分别测定.本文采用化学计量学方法来解析重叠峰并完成这两种除草剂的定量分析.甲羧除草醚和三氟羧草醚的测定线性范围分别为0.02～0.18 μg·5mL~(-1)和0.02～0.16 μg·5mL~(-1),检出限分别为0.0073 μg·5mL~(-1)和0.0068 μg·5mL~(-1).利用该方法对水样中的甲羧除草醚和三氟羧草醚进行直接测定,获得了较好的定量分析结果.     

Simultaneous Voltammetric Determination of Lead and Tin by Adsorptive Differential Pulse Stripping Method and Orthogonal Signal Correction‐Partial Least Squares in Water Samples

An adsorptive differential pulse stripping method for the simultaneous determination of lead and tin is proposed. The procedure involves an adsorptive accumulation of lead and tin on a hanging mercury drop electrode (HMDE), followed by oxidation of adsorbed lead and tin by voltammetric scan using differential pulse modulation. The optimum experimental conditions are: 0.2 mol L^?1 HNO₃, accumulation potential of ?900 mV versus Ag/AgCl, accumulation time of 200 s, scan rate of 20 mV s^?1 and pulse height of 80 mV. Lead and tin peak currents were observed in the same potential region at about ?400 mV. The simultaneous determination of lead and tin by using voltammetry is a difficult problem in analytical chemistry, due to voltammogram interferences. The resolution of a mixture of lead and tin by the application of orthogonal signal correction‐partial least squares (OSC‐PLS) was performed. The linear dynamic ranges were 0.003‐0.35 and 0.008‐0.50 μg mL^?1 and detection limits were land 3 ng mL^?1 for lead and tin, respectively. The RMSEP for lead and tin with OSC and without OSC were 2.8737, 6.0557 and 8.0941, 9.5151, respectively. The capability of the method for the analysis of real samples was evaluated by the determination of lead and tin in water samples with satisfactory results.     

微分脉冲阳极溶出伏安法测定碘离子

基于I-能被氧化生成IO₃^-的特性,以铂球电极为工作电极,研究了微分脉冲阳极溶出伏安法(DPAS)测定碘离子.由于产物IO₃^-在电极上有吸附,因而在+1.3V电清洗120s.在pH=4的0.1mol/LKH₂PO₄-K₂HPO₄缓冲溶液底液中,能检测出5.00×10^-7mol/L的I-,在5.00×10^-71.50×10^-5mol/L范围内I^-的浓度与峰电流有良好的线性关系.该方法用于海带、食用碘盐中碘的测定,取得了较好的结果.     

Simultaneous Quantitative Determination of Cadmium,Lead, and Copper on Carbon‐Ink Screen‐Printed Electrodes by Differential Pulse Anodic Stripping Voltammetry and Partial Least Squares Regression

Water is a vital commodity for every living entity on the planet. However, water resources are threatened by various sources of contamination from pesticides, hydrocarbons and heavy metals. This has resulted in the development of concepts and technologies to create a basis for provision of safe and high quality drinking water. This paper focuses on the simultaneous quantitative determination of three common contaminants, the heavy metals cadmium, lead and copper. Multivariate calibration was applied to voltammograms acquired on in‐house printed carbon‐ink screen‐printed electrodes by the highly sensitive electrochemical method of differential pulse anodic stripping voltammetry (DPASV). The statistically inspired modification of partial least squares (SIMPLS) algorithm was employed to effect the multivariate calibration. The application of data pretreatment techniques involving range‐scaling, mean‐centering, weighting of variables and the effects of peak realignment are also investigated. It was found that peak realignment in conjunction with weighting and SIMPLS led to the better overall root mean square error of prediction (RMSEP) value. This work represents significant progress in the development of multivariate calibration tools in conjunction with analytical techniques for water quality determination. It is the first time that multivariate calibration has been performed on DPASV voltammograms acquired on carbon‐ink screen‐printed electrodes.     

流通电解池-连续介质交换差示脉冲阳极溶出伏安法同时测定镉、铟

本文采用自制流通电解池,在盐酸溶液中富集Cd(Ⅱ),In(Ⅲ),经连续介质交换,在选定的乙二胺-氯化钠溶液中进行差示脉冲阳极溶出。得到的镉、铟溶出峰△Ep≥100mV。波形完好。从根本上解决了盐酸溶液中Cd(Ⅱ)、In(Ⅲ)的阳极溶出峰相重叠的问题。建立了一个灵敏、快速,同时测定镉、铟的分析方法。     

微分脉冲吸附溶出伏安法测定苯胺的研究

苯胺经重氮化、偶合反应定量生成的偶氮化合物具有很强的电活性。作者用微分脉冲吸附溶出伏安法测定偶氮化合物来定量分析苯胺的含量。以ＮＨ３·Ｈ２Ｏ－ＮＨ４Ｃｌ（ｐＨ＝１０）缓冲液为底液，富集电位为－０１５Ｖ，富集时间１２０ｓ，电位扫描速度４ｍＶ／ｓ，在－０６７０Ｖ处产生一个灵敏度高、峰形好的溶出峰。苯胺浓度在１０－９～１０－７ｍｏｌ／Ｌ时与峰电流成线性关系。用印染厂土壤、废水和广州垃圾填埋场的渗出液作标准回收试验，平均回收率分别为９８２％、９７０％、９７５％，测定的相对标准偏差为４３％、４０％、３３％。