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1.
大黄酚在0.15mol/L HAc-NaAc(pH4.9)底液中,出现一灵敏的示波极谱导数峰,峰电位为-0.45V(vs,SCE),峰电流与大黄酚浓度在2.0×10^-7-5.0×10^-6mol/L范围内成线性关系,检测限为2.0×10^-6mol/L。用于生药大黄中大黄酚的测定,回收率为92.4%-108.4%。用多种电化学手段研究体系的电化学行为,测得电极反应电子数n=2。体系具有吸附性,并  相似文献   

2.
在H2SO4-V(Ⅴ)钼酸铵-丙酮体系中,磷钒钼杂多酸有一个尖锐,灵敏的铬合吸附波,其了峰电位为-0.26V,检测下限0.04mg/L,峰电流与磷量在3-50mg/50L范围内呈线性系,所拟方法可用于碳锰和硅锰中磷的测定。  相似文献   

3.
用脱乙酰壳多糖化学修饰电极为工作电极,阳极溶出伏安法测定痕量金。在pH1~2的KCl-HCl底液中,起始电位0.20V,终止电位1.30V,富集时间5min,以0.1V/s扫速阳极溶出,峰电位在1.00V(vs.SCE),Au(Ⅲ)浓度在0.10mg/L~10mg/L范围内与峰高呈线性关系。在富集10min时,可检测0.025mg/LAu,大大提高了测定灵敏度,用于矿样测定,无需分离,结果满意。用紫外光谱和拉曼光谱研究了该法的电极过程机理。  相似文献   

4.
柚皮甙的电化学研究   总被引:1,自引:0,他引:1  
用单扫示波极谱法,柚皮甙在0.1mol/LKH2PO4中(pH=4.60)有一灵敏的二阶导数峰,峰电位为-1.43V(vs.SCE),峰电流与浓度在0.1~2.8mg/L和3.0~42mg/L范围内有良好线性关系,检出限为0.06mg/L.应用本法测定了生药枳壳中总黄酮含量,结果令人满意.实验证明柚皮甙的电极反应机理为双电子不可逆过程.此外,还证明了H2O2和·OH自由基可催化该还原峰,讨论了柚皮甙对超氧自由基O·-2的清除作用.  相似文献   

5.
金在脱乙酰壳多糖学修饰电极上的电化学行为及分析应用   总被引:3,自引:1,他引:2  
用脱乙酰壳多糖化学修饰电极为工作电极,阳极溶出伏安法测定痕量金。在pH1 ̄2的KCl-HCl底液中,超始电位0.20V,终止电位1.30V,富集时间5min,以-0.1/s扫速阳极溶出,峰电位在1.00V(vs.SCE),Au(Ⅲ)浓度在0.10mg/L ̄10mg/L范围内与峰高呈线性关系。在富集10min时,可检测0.25mig/LAu,大大提高了测定灵敏度,用于矿样测定,无需分离,结果满意。用  相似文献   

6.
吗吲哚的示波极谱法研究   总被引:2,自引:0,他引:2  
鲁毅强  胡劲波 《分析化学》1998,26(3):348-350
在0.1mol/L H2SO4溶液中,吗吲哚出现一灵敏的示波极谱导数还原峰,峰电位为-0.76V(vs.SCE),峰电流与吗吲哚浓度在1.0×10^-7 ̄5.0×10^-6mol/L范围内呈线性关系;相关系数为0.9998;检出限为3.0×10^-8mol/L。用于片剂测定,得到令人满意的结果,用线性扫描和循环伏安法等手段研究了体系的吸附性和电极反应机理,测定了有关常数和参数。证明该还原波为不可逆  相似文献   

7.
溴酸钾—碘离子体系催化动力学电位法测定痕量铜   总被引:10,自引:0,他引:10  
孙炳耀  张欣欣 《分析化学》1997,25(6):696-699
以KBrO3氧化I^-的反应为指示反应,用碘离子选择电极跟踪I^-。在适宜条件下,该指示反应为一级反应。反应速度可用电位的变化ΔE表示。当时间固定,ΔE与铜浓度在0 ̄3mg/L范围内呈线性关系,检出限为0.2μg/L。该方法已成功地用于土豆和红薯中痕量铜的测定。  相似文献   

8.
柚皮革甙的电化学研究   总被引:1,自引:0,他引:1  
邹洪 《分析科学学报》1998,14(2):114-117
用单扫示波极谱法,柚皮甙在0.1mol/LKH2PO4中(PH=4.60)有一灵敏的二阶 导数峰,峰电位为-1.43C,峰电流与浓度在0.1-2.8mg/L和3.0-42mg/L范围良好线性关系,  相似文献   

9.
徐斌  张海丽  邹欣平 《分析化学》2000,28(12):1519-1522
用线性扫描示波极谱法研究了镉(Ⅱ)-茜素紫-邻二氮菲体系的极谱行为,发现在含有0.1mol/L KCl、pH=2.85的HAc的溶液中,镉(Ⅱ)-茜素紫-邻二氮菲体系产生-灵敏的极谱吸附波,共峰电位为-0.64V(vs.SCE),峰电流与镉(Ⅱ)的浓度在5.0*10^-8-1.0*10^-6mol/L的范围内呈一性关系;检出限为3.0*10^-8mol/L。研究了电极反应机理,并用建立的方法成功地测定了废水样中的镉。  相似文献   

10.
微分吸附计时电位法测定溴莫普林   总被引:1,自引:0,他引:1  
提出一种测定新药溴莫普林(BDP)的微分吸附计时电位法。在Michaclis(MCL)缓冲液中溴莫普林于一1.33V左右产生一灵敏的微分吸附计时电位溶出峰,利用该峰测定BDP的线性范围为2.0×10^-8-3.0×10^-7mol/L,吸附富集3min检测下限为5.0×10^-9mol/L。探讨了影响灵敏度的主要因素,用循环伏安法,脉冲极谱等多种是化学方法研究了该体系的电化学行为和电极机理,认为所  相似文献   

11.
《Electroanalysis》2017,29(4):1038-1048
Novel insights into the strategy of highly precise, carbon‐based electrochemical sensors are presented by exploring the excellent properties of graphene oxide (GO) and multiwalled carbon nanotube composites (GO‐MWCNTs/CPE) for the sensitive determination of tramadol hydrochloride (TRH). Cyclic voltammetry, differential pulse voltammetry, chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) scanning electron microscopy, and X‐ray diffraction (XRD) techniques were used to characterize the properties of the sensor. The linear response obtained for TRH using the GO‐MWCNTs/CPE was found to be over the range of 2.0x10−9 to 1.1x10−3 M with a good linearity and high correlation (0.9996). The limits of detection and quantification were found to be 1.50x10−10 M and 4.99 x 10−10 M, respectively. The proposed sensor was applied for determination of TRH in the presence of presence of co‐formulated drugs ketorolac tromethamine (KTM) and paracetamol (PAR). The sensor was shown to successfully apply to the determination of TRH in plasma as real samples. Satisfactory recoveries of TRH from samples clearly revealed that the proposed sensor can be applied into clinical analysis, quality control and a routine determination of drugs in pharmaceutical formulations.  相似文献   

12.
阿齐霉素的伏安行为研究   总被引:1,自引:0,他引:1  
在1.2mol/L NaOH溶液中,阿齐霉素(azitromycin,简称AZMC)有一灵敏的还原伏安峰。当搅拌富集时间为10s,扫速为500mV/s时其吸附伏 安溶出峰电位фp=-1。34V(vs.Ag/AgC1)。用线性扫描,计时库仑法,循环伏安及脉冲极谱等多种手段研究了该体系的伏安行为 和电极反应机理。实验表明该体系属于一有吸附性的不可逆过程,测得电极反应的电子转移数n=2,体系的an=1.14  相似文献   

13.
A glassy carbon electrode modified with a coating of polypyrrole (Ppy) exhibited an attractive performance for the detection and determination of a non-steroidal and non-narcotic analgesic compound, ketorolac tromethamine (KT). Cyclic voltammetry, differential pulse and square wave voltammetry were used in a combined way to identify the electrochemical characteristics and to optimize the conditions for detection. For calibrating and estimating KT, square-wave voltammetry was mainly used. The drug shows a well-defined peak at -1.40 V vs. Ag/AgCl in the acetate buffer (pH 5.5). The existence of Ppy on the surface of the electrode gives higher electrochemical active sites at the electrode for the detection of KT and preconcentrate KT by adsorption. The square-wave stripping voltammetric response depends on the excitation signal and the accumulation time. The calibration curve is linear in the range 1 x 10(-11) to 1 x 10(-7) M with a detection limit of 1.0 x 10(-12) M. Applicability to serum samples was also demonstrated. A detection limit of 1.0 ng ml for serum was observed. Square-wave voltammetry shows superior performance over UV spectroscopy and other techniques.  相似文献   

14.
Radi A  Beltagi AM  Ghoneim MM 《Talanta》2001,54(2):283-289
The adsorption behavior of ketorolac on a hanging mercury drop electrode (HMDE) was explored by square-wave and cyclic voltammetry. The square wave voltammetric response of ketorolac depends on the parameters of the square wave voltammetry excitation signal as well as on the pH of the medium and the accumulation time. The drug was accumulated at HMDE and a well-defined peak was obtained at -1.41 V versus. Ag/AgCl (saturated KCl) in acetate buffer of pH 5.0. A square-wave adsorptive stripping voltammetric method for the quantitative determination of ketorolac was developed. The linear concentration range was 1x10(-10)-1x10(-8) when using 300 s accumulation at -0.8 V. The detection limit of ketorolac was 1.0x10 (-11)M . The precision was excellent with relative standard deviation of 3.85% at concentration of 5x10 (-8)M after 60 s accumulation time. Applicability to serum samples was illustrated. A detection limit of 14 ng per ml of serum was obtained.  相似文献   

15.
Ketorolac tromethamine is a potent nonsteroidal anti-inflammatory drug that is widely used in the treatment of moderate to severe pain. A new method was developed and validated for quantifying ketorolac (the free acid of the tromethamine salt) in human plasma by high-performance thin-layer chromatography. The stationary phase was silica gel 60, and the composition of the mobile phase was n-butanol-chloroform-acetic acid-ammonium hydroxide-water (9 + 3 + 5 + 1 + 2, v/v). The densitometric analysis of ketorolac was performed at 323 nm. The method was validated for precision (repeatability and reproducibility), accuracy, and sensitivity. Repeatability was 10.11% [coefficient of variation (CV)] and reproducibility was 12.18% (CV) as the maximum variation. Accuracy was determined at 3 different concentration levels, and results were within +/-15% of the predetermined range. Data were fitted by a linear mathematical function (linear regression). The calibration graph was linear in the range of 200-2000 ng/mL. Average recovery was 73.67%. The method proved to be accurate, precise, and sensitive for the ketorolac tromethamine quantification.  相似文献   

16.
依沙吖啶在玻碳电极上的阳极伏安行为   总被引:4,自引:0,他引:4  
用直流伏安法(DCV)、微分脉冲伏安法(DPV)和循环伏安法(CV)在玻璃电极(GCE)上研究了依沙吖啶(EAD)在不同介质中的阳极伏安行为,发现在0.1mol/L氢氧化钠溶液中于0.38V(vs.Ag/AgCl)左右产生一个良好的阳极氧化峰,浓度在0.05-80mg/L之间与其峰电流呈线性关系,用本法不需要分离,可直接测定药物制剂和加标尿样,RSD为1.4%-2.7%(n=10)。尿样中EAD的回收率为89%-95%。探讨了EAD在GEC上的电极反应机理。  相似文献   

17.
王桂芬  朴元哲 《分析化学》1998,26(12):1490-1493
应用循环伏安法、微分脉冲伏安法对多菌灵在破碳电极上的电化学行为及其测定进行了研究。在pH=9.0的2mol/L NH3-NH4Cl底液中,对其进行循环伏安扫描,发现于0.61V(vs.Ag/AgCl)产生一灵敏的氧化峰。微分脉冲伏安法殉菌灵的检测限为4×10^-8mol/L。多菌灵的浓度在5.0×10^-7 ̄1.0×10^-5mol/L间与微分脉冲伏安峰电流呈线性关系(r=0.9942)。对于1×  相似文献   

18.
采用电聚合的方法制备了聚对氨基苯磺酸(PABSA)修饰电极,以循环伏安法和差分脉冲伏安法研究了桑色素在该修饰电极上的电化学行为。PABSA和黄酮类药物桑色素的π-π共轭作用使得桑色素在该修饰电极上产生的氧化峰更加灵敏。实验发现,在pH 7.0的磷酸盐缓冲介质中,桑色素在0.214 V处产生灵敏的氧化峰。在优化实验条件下,采用差分脉冲伏安法对桑色素进行定量测定,桑色素的氧化峰电流与其浓度呈良好的线性关系,线性范围为5.0×10-7~1.0×10-3 mol/L,检出限为1.0×10-7 mol/L。将该修饰电极用于桑枝生物样品中桑色素含量的测定,结果满意。该方法具有灵敏度高、重现性好的特点,且该修饰电极稳定性高,可重复使用。  相似文献   

19.
杨运发 《分析化学》1996,24(2):161-163
本文对羟乙芦丁在玻碳电极上的阳极微分脉冲安行为进行了研究,发现在Na2HPO4溶液中(pH=8.95)于+0.64V(vs.Ag/AgCl)左右产生一个良好的阳极氧化伏安峰,浓度在5~60mg/L之间与峰电流呈线性关系,不需分离直接测定了片剂中的羟乙芦丁含量。电极反应为扩散速率控制的不可逆可程。  相似文献   

20.
研究了呋塞米(FUR)在3-氨基丙基三氧基硅烷(APTS)和石墨烯(RGO)复合修饰碳糊电极(APTSRGO/CPE)上的电化学行为。实验结果表明,与CPE相比,APTS-RGO/CPE对呋塞米的电化学氧化显著增强,其氧化峰电流增加3.4倍。同时采用循环伏安法(CV)、计时电流法(CA)测定了FUR在APTS-RGO/CPE上的电极反应动力学参数,用微分脉冲伏安法(DPV)测得FUR氧化峰电流与浓度的线性范围为1.3~330 mg/L,检出限(LOD,S/N=3)为1.1×10-2mg/L。将该修饰电极应用于市售呋塞米片剂的检测,相对标准偏差(RSD)为0.4%~4.4%,回收率为98.5%~99.7%,检测结果符合电化学定量测定要求。  相似文献   

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