共查询到19条相似文献,搜索用时 78 毫秒
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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% 相似文献
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用差分脉冲阳极溶出伏安法同时测定了8种中药材样品中铜、铅、镉的含量,它们的溶出电位依次是-0.15 V、-0.45 V、-0.65 V;铜、铅浓度在4.0×10-10~1.0×10-7g/mL范围内与峰电流呈线性关系,线性回归方程分别为y=378.84x(R2=0.9985)、y=661.96x(R2=0.9937)(x为浓度,单位10-6g/mL),镉浓度在4.0×10-10~8.0×10-7g/mL范围内与峰电流呈线性关系,回归方程为y=588.72x(R2=0.9963)(x为浓度,单位10-6g/mL),其检出限依次为1.0×10-11g/mL、1.8×10-11g/mL、1.0×10-11g/mL。此方法用于中草药样品中铜、铅、镉的测定,其回收率依次为88.06%、105.74%,、104.54%,方法简便,灵敏度高,结果准确可靠。 相似文献
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本文报导了阳极溶出伏安法测定化妆品粉中的铅。探计了处理粉样的最佳条件。样品先经硝酸-高氯酸混合液消化,然后在醋酸-醋酸钠介质中(pH=5.6)测得铅溶出峰。峰高与1×10~(-9)~9×10~(-7)摩尔/升范围内的铅浓度之间有良好的线性关系。应用本方法在SV-1溶出伏安仪上测定了若干种化妆品粉中的铅含量。方法的精密度与准确度均符合微量分析的要求。 相似文献
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铋膜电极阳极溶出伏安法测食盐中锌含量 总被引:3,自引:0,他引:3
用铋膜电极代替汞膜电极可避免环境污染。采用玻碳电极同位镀铋在酸性的KSCN介质中测定食盐中锌,结果峰形好、灵敏度高、峰电流值大,检测限为7.8×10^-8mol/L,线性范围为2.0×10^-6mol/L~1.3×10^-5mol/L,加标回收率为92.2%-102.2%。 相似文献
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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对氢溴酸右美沙芬的伏安行为进行了研究。实验结果表明,在pH6.5的B-R(Britton-Robinson)缓冲底液中,氢溴酸右美沙芬在+1.01 V(vs.Ag/AgCl)处有一明显的氧化峰,在4.0×10-6~8.0×10-5mol/L范围内与峰电流呈良好的线性关系(r=0.995 1),检出限为5.6×10-7mol/L。用该方法对氢溴酸右美沙芬片进行了测定,回收率为98.6%~102.9%,结果令人满意,还对其电极反应机理进行了初步探讨。 相似文献
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方波溶出伏安法测定蔬菜中铜和锌 总被引:5,自引:0,他引:5
研究了用方波溶出伏安法测定蔬菜中铜和锌含量的方法。在pH=10的1 mol/L NH3H2O-NH4C l缓冲溶液中,于-0.12V、-0.93V(vs.SCE)分别产生铜和锌的灵敏峰,其峰高与离子的浓度在0.1~3 mg/L(Cu2+∶R2=0.9983)和0.4~5 mg/L(Zn2+∶R2=0.9924)之间存在良好的线性关系,富集时间300 s。用标准曲线法定量,分别测定蔬菜中的铜和锌。该测定方法简便快速、灵敏度高,适用于蔬菜中铜和锌含量的分析。 相似文献
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阳极溶出伏安法同时测定海水中铜、铅、镉、锌 总被引:3,自引:0,他引:3
采用微分脉冲阳极溶出伏安法同时测定了海水中Cu、Pb、Cd、Zn4种痕量元素,在选定最佳实验条件下,通过标准加入法对海水的Cu、Pb、Cd、Zn进行分析,其相对标准偏差分别为5.6%、4.6%、1.80%、1.98%,而回收率分别为98.0%~105.6%、95.3%~106.5%、90.0%~107.4%和90.8%~103.5%,测定结果令人满意。 相似文献
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Mehran Javanbakht Faten Divsar Fatemeh Fatollahi Mohammad Reza Ganjali Marzieh Chaloosi 《Electrochimica acta》2009,54(23):5381-5386
This study introduces the design of an anodic stripping voltammetric (ASV) method for the silver ion determination at a carbon paste electrode (CPE), chemically modified with phenylthiourea-nanoporous silica gel (Tu-SBA-15-CPE). The electroanalytical pro includes two steps: preconcentration of metal ions at an electrode surface, followed by quantification of the accumulated species by differential pulse anodic stripping voltammetric methods. Factors affecting the performance of the anodic stripping were investigated, including the modifier quantity in the paste, the electrolyte concentrations, the solution pH and the accumulation potential or time. The most sensitive and reliable electrode contained 10% Tu-SBA-15 and 90% carbon paste. The accumulation potential and time were set at, −200 mV and 300 s, respectively, and the scan rate at 50 mV s−1 in the scan range of −200 to 700 mV. The resulting electrode demonstrated a linear response over range of silver ion concentration of 8.0-80 pmol/L with detection limit (S/N = 3) of 5 pmol/L. The prepared electrodes were used for the silver determination in sea and tap water samples and very good recovery results were obtained. The accuracy was assessed through recovery experiments and independent analysis by graphite furnace atomic absorption spectrometry. 相似文献
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The differential pulse adsorptive stripping voltammetric behavior of selenium (IV)-p-aminobenzene sulfonic acid-cetyltrimethylammonium bromide system at a bismuth-coated glassy carbon electrode (BiFE) has been investigated. A well-defined and sensitive stripping peak of the selenium (IV)-p-aminobenzene sulfonic acid complex was observed at −0.76 V (vs. SCE) in a 0.15 mol/L acetate solution (pH 2.9) at a deposition potential of −0.40 V (for 120 s). The linear range was 2-30 μg/L and the detection limit for an accumulation time of 300 s was 0.1 μg/L. This method was applied to determine the trace amount of selenium in the samples. 相似文献
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An electrochemical method for the determination of azinphos-methyl and parathion-methyl in honey is presented. The determination is established by adsorptive stripping differential pulse voltammetry at hanging mercury working electrode.In contrast to the chromatographic methods for the determination of pesticide residues, the sample preparation of the proposed method is minimal; analytes were extracted from honey samples with a mixture of (acetone):(Britton-Robinson buffer) and then were analyzed without any additional pretreatment.The response of the analytes either individually or as a mixture was studied for a series of deposition time and molar ratio. Two quantitation protocols were compared, using either the external calibration or the standard addition method. Accuracy was tested with spiked honey samples obtaining good recovery values. The limit of detection for the honey sample (for deposition time of 10 s) was calculated 51.71 μg kg−1 for MeP and 65.87 μg kg−1 for AzMet. 相似文献