共查询到20条相似文献,搜索用时 171 毫秒
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在稀硫酸介质中,碘离子能快速、定量地还原高锰酸根,在加入碘离子前后,高锰酸钾溶液在波长525nm处的吸光度发生显著变化,且吸光度之差ΔA与加入的碘离子的浓度成正比,确定了最佳反应条件,建立了高锰酸根褪色光度法测定食盐中微量碘离子的新方法。方法的线性范围为0-20μg/mL,线性回归方程为ΔA=0.0165c 0.0041,相关系数r=0.9987,检出限为0.17μg/mL。用于食盐中微量碘离子的测定,加标回收率为91.0%~95.0%.相对标准偏差为0.35%~0.75%。 相似文献
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断续流动注射-催化原子荧光光谱法测定碘 总被引:6,自引:0,他引:6
基于碘对亚砷酸-硫酸铈的催化反应,断续流动进样,用氢化物发生.原子荧光光谱法直接测定As(Ⅲ)的浓度变化,建立了微量碘间接测定的方法。在实验条件下,碘离子的线性范围为0.80μg/L;相对标准偏差为2.3%;检测限为4μg/L.加标回收率为92.5%-98.2%。测定结果与硫氰酸铁-亚硝酸催化动力学法相比具有很好的一致性。 相似文献
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严小平 《广东微量元素科学》2007,14(10):46-49
研究了在稀硫酸介质中,痕量碘离子对亚硝酸根催化溴酸钾氧化甲酚红的阻抑作用,建立了测定痕量碘离子的阻抑动力学光度分析的新方法。测定碘离子的线性范围为0~0.62μg/mL,检出限为7.43×10-9 g/mL。已用于食品中痕量碘的测定,结果满意。 相似文献
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A simple and rapid method is proposed for the determination of ultra trace amounts of formaldehyde. It is based on the catalytic effect of formaldehyde on the oxidation of Brilliant cresyl blue by bromate. The reaction is monitored photometrically by measuring the decrease in absorbance of the dye. Formaldehyde in the range of 0.005–2.300 μg/mL can be determined with a limit of detection of 0.003 μg/mL. The relative standard deviation for ten replicate measurements of 1.5 μg/mL formaldehyde is 0.1%. The method was used for the determination of formaldehyde in real samples with satisfactory results. 相似文献
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甲基绿-高碘酸钾系统催化动力学光度法测定痕量铱(Ⅳ) 总被引:1,自引:1,他引:0
基于以H3PO4为反应介质,用HAc-NaAc(1+8)(pH5.7)作缓冲溶液,在沸水浴中加热条件下,痕量铱(Ⅳ)能灵敏地催化高碘酸钾氧化甲基绿的褪色反应,建立了一种测定痕量铱(Ⅳ)的新催化光度法。研究了反应的最佳条件。催化反应吸光度A与非催化反应吸光度A0的差值ΔA与铱(Ⅳ)的质量浓度ρ在0~2.0μg/25mL范围内呈良好的线性关系。检出限为2.97×10-10g/mL。对1μg/25mL铱(Ⅳ)测定的相对标准偏差为1.7%(n=11)。测定了动力学参数。该催化反应对铱(Ⅳ)为一级反应,总反应为准一级反应。反应的表观速率常数为4.613×10-4/s,表观活化能为40.56kJ/mol。该方法用于分子筛样品和活性炭中痕量铱(Ⅳ)的测定,回收率97.9%~104.4%。 相似文献
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采用催化过氧化氢氧化Ni(Ⅱ)-铬蓝黑R络合物光度法测定汞,通过优化对比实验,确定最佳反应条件为在pH 4.12的HAc-NaAc缓冲溶液中,以2.00 mL4g/L聚乙烯醇(PVA)作表面活性剂,5.00 mL H_2O_2(1+9)溶液可氧化1.00 mL0.001 mol/L Ni~(2+)溶液与1.00 mL 0.400g/L铬蓝黑R溶液反应生成的Ni(Ⅱ)-铬蓝黑R络合物,75℃水浴加热,汞对该反应具有明显催化作用.在波长571 nm处催化体系和非催化体系的吸光度差值最大.Hg(Ⅱ)在0.1~2.0g/L范围内符合朗格一比尔定律,检出限为3.2×10~(-9)g/L.经实际水体样本论证,本法可用于自然水体中痕量汞的直接测定. 相似文献
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E. G. Khomutova V. A. Zagorodnikova S. A. Zagorodnikova O. I. Ostanina 《Journal of Analytical Chemistry》2013,68(7):611-615
A catalytic method has been developed for the individual determination of trace iridium and rhodium using the oxidation of sulfarsazene by potassium periodate as an indicator reaction in a flow-injection system. The analytical range is from 0.10 to 2.0 μg/mL iridium and from 0.0010 to 0.027 μg/mL rhodium. The detection limits are 0.0074 μg/mL iridium and 0.00095 μg/mL rhodium; the determination error does not exceed RSD = 4% in model solutions. The method is selective in the presence of the majority of colored and platinum-group metals. The accuracy of the results has been confirmed by the standard addition method. 相似文献
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A rapid, simple, and sensitive kinetic method is developed for the determination of trace amounts of Sb(V). The method is
based on the reaction of Sb(V) with iodide in acidic media in the presence of methylene blue. The reaction was monitored spectrophotometrically
by measuring the decrease in the absorbance at 664 nm by a fixed-time technique of 60 s. The method allowed the determination
of Sb(V) at concentrations between 0.01 and 2.2 μg/mL. The limit of detection was 0.006 μg/mL and the relative standard deviation
for ten replicate measurements of 0.5 μg/mL Sb(V) was 1.2%. The method was applied to the determination of Sb(V) in tap water
and spring water with satisfactory results.
The text was submitted by the authors in English. 相似文献
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基于0.004 mol/L的柠檬酸介质中,痕量V(Ⅴ)催化KBrO3氧化甲基紫的褪色反应,建立了测定痕量V(Ⅴ)的动力学光度法。方法的检出限为1.23μg/L,线性范围为0~0.16μg/mL。讨论了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响,确定了该体系反应的最佳条件。在25 mL溶液中,测定2.0μg V(Ⅴ)的RSD为1.9%(n=11)。方法可用于测定小麦和苹果中的痕量V(Ⅴ),RSD为1.1%~2.7%,标准加入回收率为97.6%~99.0%。 相似文献