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1.
分光光度法测定饮料食品中痕量有机锗和无机锗的研究   总被引:6,自引:1,他引:5  
本文研究了在溴化十六烷基三甲基铵(CTMAB)抗坏血酸(Vc)存在下,苯基荧光酮(Pf)光度法测定痕量锗的最佳实验条件及配合物的组成,从而建立了测定痕是锗的新方法,其方法的灵敏度ε=1.034×10^5L.mol^-1.cm^-1锗含量在0-16.8μg/25mL范围内符合比耳定律,稳定性好,操作简便,快速。应用本法测定了矿泉水,茉莉花茶,大蒜中有机锗和无机锗的含量,回收率在91.6%-103.5  相似文献   

2.
火焰原子吸收法测定有机锗(Ge-132)中的锗,线性浓度范围为0-1.25mg/mL,方法精度为1.2%,相对标准偏差〉2%,平均回收率为99.5%,杂质Pb和As用塞曼石墨炉原子吸收测定,Pb用(NH4)2HPO4+Mg作改进剂,As用Pd作改进剂,特征质量分别为8.2pg和8pg,相对标准偏差分别为2.1%和2.2%,并讨论了有关机理问题。  相似文献   

3.
火焰原子吸收法测定有机锗(Ge.132)①中的锗,线性浓度范围为0-1.25mg/mL,方法精度为1.2%,相对标准偏差<2%,平均回收率为99.5%。杂质Pb和As用塞曼石墨炉原子吸收测定,Pb用(NH_4)_2HPO_4+Mg作改进剂,As用Pd作改进剂,特征质量分别为8.2pg和8pg,相对标准偏差分别为2.1%和2.2%,并讨论了有关机理问题。  相似文献   

4.
合成了新试剂N-已基-N′-(对苯磺酸钠)硫脲(HXPT)并确定了其结构。研究了它与钯(Ⅱ)反应的条件试验,结果表明,在pH 5.4~5.8 的HAc-NaAc介质中,有溴化十六烷基三甲胺(CTMAB)的存在,试剂与钯(Ⅱ)形成稳定的黄色配合物,最大吸收波长为296.8 nm ,表观摩尔吸光系数为2.21×105 L·m ol- 1 ·cm - 1,钯浓度在1~7 μg·25 m L- 1 范围内,符合比尔定律。方法简便、快速、选择性好,用于催化剂、矿样中微量钯的测定,结果满意。  相似文献   

5.
食品中无机锗与锗—132的分别测定   总被引:12,自引:1,他引:11  
采用氢化物发生-原子荧光光谱法(HG-AFS),分别测定了保健饮品中的无机锗和β-羧乙基锗倍半氧化物(即锗-132),同时对于天然食品中无机锗和锗-132分别测定的条件也进行了初步的探讨。  相似文献   

6.
研究新合成的水溶性光度试剂N-壬基-N′-(氨基对苯磺酸钠)硫脲(NPT)与钯(Ⅱ)的显色反应,结果表明,在pH5.8~6.6的HAc-NaAc缓冲体系中,Pd2+与NPT形成14的黄色水溶性配合后物,CTMAB对反应有明显的增敏作用,配合物的最大吸收波长位于297.6nm,表观摩尔吸光系数ε297.6=1.27×105Lmol-1cm-1,钯含量在2~11.2μg/25mL范围内服从比尔定律,50种离子不干扰测定,其灵敏度和选择性是目前测钯(Ⅱ)的最好的试剂之一。该法用于阳极泥和催化剂中钯的测定,均获满意结果。  相似文献   

7.
王岭梅 《光谱实验室》1999,16(2):177-179
在pH=5.0HAc-NaAc缓冲介质中,吐温-80存在下,2-(4-安替比林偶氮)-5-二乙氨基苯胺(ADEA)与钯生成2:1红色络合物,λmax=530nm,δ-6.15×10^5L.mol^-1.cm^-1,钯的含量在0-20μg/25mL内符合比耳定律,本方法用于钯催化剂中痕量钯的测定,结果令人满意。  相似文献   

8.
石墨炉原子吸收法测定麦芽粉中的锗和硒   总被引:11,自引:0,他引:11  
本文叙述了平台石墨炉原子吸收法测定麦芽粉中的锗和硒,采用Pd+Ni和Pd基体改进剂,使锗和硒的灰化温度分别提高到1400和1200℃,有效地消除了基体干扰。方法特征量为31pg(Ge)和23pg(Se),检出限为28pgGe和62pgSe(3σ)。对含22 ̄110μg/gGe和18 ̄35μg/gSe的样品测定,相对标准偏差为Ge3.7 ̄5.6%(n=9),Se4.3 ̄6.5%(n=9),回收率在9  相似文献   

9.
在pH=5.0HAc-NaAc缓冲介质中,吐温-80存在下,2-(4-安替比林偶氮)-5-二乙氨基苯胺(ADEA)与钯生成2∶1红色络合物,λmax=530nm,ε=6.15×104L·mol-1·cm-1,钯的含量在0—20μg/25mL内符合比耳定律,本方法用于钯催化剂中痕量钯的测定,结果令人满意。  相似文献   

10.
正丁醇萃取石墨炉原子吸收法测定微量锗   总被引:3,自引:0,他引:3  
建立了萃取-石墨炉原子吸收法测定中草药、植物样品及水系沉积物中微量锗的方法。锗与钼酸铵在0.3mol/L的硝酸介质中,可以生成稳定的锗钼杂多酸盐,并能被正丁醇萃取,有机相直接进样测定。本方法采用钼酸铵浸渍处理石墨管,直接测定了枸杞、蕨麻等植物样品及水系沉积物中的微量锗。方法的检出限为6.0×10(-12)g,对于30ng/mL锗的测定相对标准偏差为5.0%  相似文献   

11.
Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.  相似文献   

12.
A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.  相似文献   

13.
A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.  相似文献   

14.
Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·104 Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.  相似文献   

15.
The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.  相似文献   

16.
17.
A transient suppression method for piezoelectric ceramic transducer is presented. By adding some special pedestal pulses to the original transmitted signal, the transient effects in the output of the transducer can be just precisely transmission by use of a narrowband transducer. canceled, thereby achieving the broadband The experimental results show that the transient responses of the sinusoid pulses and coded signals are suppressed successfully and the acoustic waveforms radiated into the surrounding water are improved significantly.  相似文献   

18.
We experimentally demonstrate amplitude squeezed soliton utilizing intensity-dependent self-phase modulation in an asymmetric Sagnac interferometer.The system.whose components are connected via ferrule connector/physical connection(FC/PC)fiber connectors,constitutes all-fiber configuration to generate squeezed soliton.Soliton amplitude reduction measured by homodyne detection is near 4.0 dB below the shot-noise level.Optimal squeezing fields in both simple and compact all-fiber configuration are obtained.  相似文献   

19.
The(2 1)-dimensional nonlinear Schr(o)dinger(NLS)equation with spatially inhomogeneous nonlinearities is investigated,which describes propagation of light in(2 1)-dimensional nonlinear optical media with inhomogeneous nonlinearities.New types of optical modes and nonlinear effects in optical media are presented numerically.The results reveal that the regular split of beam can be obtained in (2 1)-dimensional nonlinear optical media with inhomogeneous nonlinearities,by adjusting the guiding parameter.Furthermore,the stability of beam regular split is discussed numerically,and the results reveal that the beam regular split is stable to the finite initial perturbations.  相似文献   

20.
In the real-world application of face recognition system, owing to the difficulties of collecting samples or storage space of systems, only one sample image per person is stored in the system, which is so-called one sample per person problem. Moreover, pose and illumination have impact on recognition performance. We propose a novel pose and illumination robust algorithm for face recognition with a single training image per person to solve the above limitations. Experimental results show that the proposed algorithm is an efficient and practical approach for face recognition.  相似文献   

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