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 共查询到19条相似文献,搜索用时 328 毫秒
1.
滕文锋  彭茵  杨波 《光谱实验室》2004,21(2):402-404
通过巯基棉富集分离后 ,用火焰原子吸收光谱法测定了食盐中的痕量镉 ,研究了巯基棉富集 Cd( )的条件 ,实验回收率 92 %— 98% ,RSD<6 .0 %。本实验方法简便 ,可用于食盐中痕量镉的测定  相似文献   

2.
巯基棉分离富集-火焰原子吸收法测定中药材中的铅   总被引:4,自引:0,他引:4  
通过巯基棉分离富集后 ,采用火焰原子吸收方法成功测定了怀药 (怀山药、怀牛膝、怀菊花、)中的痕量铅 ,并对富集铅的条件及洗脱条件、干扰因素进行了探讨。本实验回收率在 97 0 %~ 1 0 2 0 % RSD <4 3 %。此方法简单易行、方便快速 ,结果令人满意 ,可用于测定中药材中的痕量铅。  相似文献   

3.
彭茵  滕文锋 《光谱实验室》2004,21(4):674-676
巯基棉分离富集 ,火焰原子吸收光谱法同时测定钙盐中的痕量铅、镉 ,大量钙不干扰铅、镉的测定。方法简单易行 ,结果令人满意的。  相似文献   

4.
巯基棉分离富集-FAAS法测定爆玉米花中痕量铅   总被引:2,自引:0,他引:2  
周兆平  彭茵 《光谱实验室》2000,17(1):118-119,120
本文借助巯基棉分离富集技术,以火焰原子吸收光谱法(FAAS)测定爆玉米花中痕量铅。该方法采用巯基棉做分离富集剂,简便易行,并能有效的消除共存元素的干扰,回收率为97.5%-106.0%。  相似文献   

5.
本文研究了用巯基棉直接富集蜂蜜中的痕量铅,使铅与干扰物质分离,再用石墨炉原子吸收法测定铅的方法。一、实验部分(一)仪器与试剂1.日本岛津AA-670原子吸收分光光度计。2.GFA-4A型石墨炉原子化器。3.硝酸铅(高纯)。4.巯基棉:参照文献[1]制备。(二)实验原理  相似文献   

6.
本文对巯基棉同时富集铅,汞的条件及洗脱条件,氢化物-原子荧光法测定铅、汞的条件及干扰元素进行探讨,并拟定了测定地下水中超痕量铅、汞的灵敏、可靠的分析方法,实验结果表明,此方法的各项指标均满足地下水分析要求。  相似文献   

7.
利用巯基棉富集银,将富集银后的巯基棉灰化,用王水将银氧化并控制30%的盐酸酸度,火焰原子吸收光谱法测定卤水中的痕量Ag.对流速、富集时间和酸度等因素进行了实验,方法可用于卤水中痕量银的分析.检出限为(3S/N)=0.002mg/L,加标回收率为99.0%-101%.相对标准偏差为3.21%(n-11).  相似文献   

8.
本文主要研究了利用巯基棉在pH5—6.5的微酸性条件下,富集废水中痕量镓、镉、铅等元素的化学光谱测定。进行了一系列化学干扰及光谱条件等试验。用本法测定了废水样品,获得了较满意的结果。该法具有简便、快速及灵敏的特点。  相似文献   

9.
巯基棉分离富集-FAAS法测定海水中的痕量镉   总被引:1,自引:1,他引:0  
彭茵  张莹 《光谱实验室》2004,21(6):1213-1214
借助巯基棉分离富集技术 ,以火焰原子吸收光谱法测定海水中的痕量镉。该方法的回收率为94 .0 %— 97.0 % ,相对标准偏差为 4 .9%。结果表明 ,该方法简单易行 ,具有较好的准确度和精密度  相似文献   

10.
浊点萃取-石墨炉原子吸收法测定高盐样品中的痕量铅   总被引:3,自引:2,他引:1  
在pH 6~7的缓冲体系中,样品溶液中的痕量铅与加入的吡咯烷二硫代氨基甲酸铵(APDC)为络合剂形成稳定的配合物.通过70℃恒温水浴3 h,铅配合物被萃取到表面活性剂相并与水相分开.分离后的表面活性剂相室温就可配成上机待测样液.此法不但将大量基体离弃在水相,从而消除高盐带来的高背景信号干扰,并将水样或1%食盐溶液的痕量铅富集10~100倍.用氘灯校正背景石墨炉原子吸收法进行测定,方法检出限:食盐0.000 5 μg·g-1,水样0.01 μg·L-1.回收率为92.3%~104%.用于食盐、海水、井水中痕量铅的测定,结果令人满意.  相似文献   

11.
张莹  石敏 《光谱实验室》1997,14(6):54-57
偏硼酸钠,无水乙酸钠,无水碳酸钠,磷酸氢二钠等试剂中的痕量镉,经巯基棉分离和富集后,以火焰原子吸收光谱法进行测定。方法简便,快速,测定的相对标准偏差均小于4.61%。  相似文献   

12.
沉淀富集-火焰原子吸收光谱法测定水中的铅和镉   总被引:2,自引:1,他引:1  
水样用Mg(OH)2沉淀,沉淀富集后采用校准曲线法,火焰原子吸收光谱法直接测定了水样中的铅和镉。所测定的水样中铅和镉的含量远低于国家限定标准,采用此方法回收率为70%—110%。本法简单、快速,结果令人满意。  相似文献   

13.
微色谱柱分离—FAAS法测定镀铬液中铁、铜、锌   总被引:5,自引:0,他引:5  
本文研究了减压条件下微孔色谱柱分离富集镀铬液中杂质无素铁、铜、锌的柱性能,确定了最佳富集条件,在近中性介质中,以H^ 型732强酸性阳离子交换树脂于φ3×70mm微孔色谱柱中富集镀铬液中铁、铜、锌,与铬(Ⅵ)分离,以蒸馏水为淋洗液,被吸附的离子用4.5mol/L硝酸洗脱后用火焰原子吸收光谱法测定,方法简便、快速,灵敏度高,标准加入回收率在98%-104%之间,用于镀铬液中铁、铜、锌的测定,结果令人满意。  相似文献   

14.
The necessity, prospects, and possibility of development of an underground multipurpose device for detecting high-energy penetrating particles (muons) are described. The use of lead as an absorber and plastic scintillators with gadolinium allow the simultaneous use of the device as an ionization-neutron calorimeter and a pairmeter for detecting nuclear and electromagnetic cascades from penetrating particles and separating ones from the others. The presented results of calculations of the pairmeter characteristics using the GEANT program show the possibility of estimating the muon energy from 100 GeV to 200 TeV with an accuracy of 40% for a version with 150 layers (2 cm lead + 1 cm plastic each).  相似文献   

15.
The ferroelectric-antiferroelectric phase transitions in lead zirconate-titanate-based solid solutions have been considered with allowance made for anharmonicity of the crystal potential. In the phase diagram of lead zirconate-titanate, the boundary separating the regions of the ferroelectric and antiferroelectric states are shifted toward higher titanium concentrations. The calculated and experimental phase diagrams are presented for such cases.  相似文献   

16.
Ferrosilicon is used as a medium for separating different minerals in beneficiation, and is recovered by magnetic separation, then recycled. Commercial grades exhibit different magnetic properties and a range of chemical compositions, and the former can lead to non-recovery and cost implications. A study was carried out on samples of commercial ferrosilicon in an attempt to characterise the varying saturation magnetism (Satmagan) value. The samples had Satmagan values between 56 and 68% (as measured against a ferrite standard). Mössbauer results showed that peaks became more pronounced with increased Satmagan value. This indicates that the order of the Fe3Si DO3 phase increased with higher Satmagan value. Scanning electron microscopy revealed that the microstructure comprised dendrites (with 30–34 at. % Si) which were surrounded by a eutectic comprising 22–31 at. % Si, with the dendrites being the major phase.  相似文献   

17.
A two-dimensional correlation experiment is introduced that records the sum and difference chemical shift of two scalar or dipolar coupled nuclei. Statistical results indicate that the suggested pulse scheme can significantly increase the possibility of separating chemical shift contributions due to residue type and backbone conformation in immobilized peptides and proteins. Experimental applications demonstrate the theoretical concept and lead to the predicted resolution enhancement between different amino acid types and among protein residues of different secondary structure.  相似文献   

18.
The distribution of a microwave electric field in the space charge region (SCR) of semiconductors is found from a joint solution of the diffusion-drift equation and the Poisson equation. Large enriching bends of the bands lead to screening of the microwave field by SCR free carriers, with the result that the microwave power absorption is limited when the bends become larger. An expression is found for the relation between the quality factor Qg of the capacitive gap of the measuring resonator and the size of the bends. Plots of maximum error of measurement of the conducitivity of semiconductors due to neglect of absorption in the SCR against measured values of Qg are obtained.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 18–22, November, 1981.  相似文献   

19.
We have studied the nanofriction of Ne monolayers with a quartz-crystal microbalance technique at temperatures below 6.5 K and in ultrahigh-vacuum conditions. Very homogeneous and smooth lead electrodes have been physically deposited on a quartz blank at 150 K and then annealed at room temperatures. With such a Pb-plated quartz-crystal microbalance, we have observed a pronounced depinning transition separating a low-coverage region, where the film is nearly locked to the oscillating electrode, from a high-coverage region characterized by slippage at the solid-fluid boundary. Such a behavior has been found to be very reproducible. These data are suggestive of a structural depinning of the solid Ne film when it becomes incommensurate with the lead substrate, in agreement with the results of an extensive molecular-dynamics study.  相似文献   

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