Enhancement effect of iron addition for the decomposition of organic mercury as studied by continuous flow analysis with cold vapor atomic absorption spectrometric detection

Summary A continuous flow analysis is described for the determination of total mercury by cold vapor atomic absorption spectrometry. Organic mercury compounds such as methylmercury(II) chloride, ethylmercury(II) chloride and phenylmercury(II) chloride were decomposed by potassium peroxodisulphate with addition of ferric chloride as catalytic reagent. The reducing reagent used was tin(II) chloride in sodium hydroxide solution. With 1,000 mg Fe/l added in the decomposition process, we found that methylmercury(II) chloride and ethylmercury(II) chloride gave response signals similar to those of mercury(II) chloride. The proposed method was applied to the analysis of total mercury in waste water. Permanent address: Department of Chemistry, Faculty of Mathematics and Natural Sciences, Andalas University, Padang, West Sumatra, Indonesia     

Nuclear activation techniques in the life sciences 1978

The proceeding of the IAEA symposium held in 1978 on nuclear activation techniques in the life sciences are reviewed. A total of 56 papers are reviewed on methodology, analytical quality control, comparisons between neutron activation analysis and other methods, and applications of activation analysis in biology and medicine (including in-vivo activation analysis) and in public and environmental health. The materials analysed in the papers are adjusted in connection with the elements determined and the purposes of the study. Those elements are tabulated together with the analytical methods used for the element determination. The standard reference materials analysed for the check of the reliability of analysis are also arranged. Proc. Symp. Nuclear Activation Techniques in the Life Sciences, IAEA, Vienna, 1978.     

The flameless atomic absorption spectrometric determination of aluminum with a carbon atomization system

The atomic absorption spectrometry of aluminum with a carbon tube atomizer is described, with particular reference to the heating cycle, argon flow rate and amplifier time constant. Interferences are eliminated by pre-atomization heating or with a hydrogen-argon-entrained air flame. Under optimal conditions, the sensitivity (1 % absorbance) is 5·10^?11g, and the relative standard deviation is 2.3 for 2.5 ng Al.     

Atomic absorption spectrometry of traces of tri- and hexavalent chromium

Summary Atomic absorption spectrometry combined with extraction is described for the determination of tri- and hexavalent chromium. The chromium diethyldithiocarbamate chelate was used for chromium (VI), whereas hydroxyquinolate or thenoyltrifluoroacetonate chelate for chromium(III). The method is rapid and precise.

---

Zusammenfassung Extraktion und darauffolgende Messung der Atomarabsorption wurden zur Bestimmung von drei- und sechswertigem Chrom verwendet. Die Chelatverbindung mit Diäthyldithiocarbamat wurde für Chrom(VI), der Chelatkomplex mit Hydroxychinolin oder Thenoyltrifluoraceton für Chrom(III) verwendet. Das Verfahren ist rasch und genau.

     

Laser isotope separation of tritium from deuterium: CO2-laser-induced multiphoton dissociation of C2TF5 in C2DF5

Isotope separation of tritium from deuterium in heavy water was attempted by CO₂-laser-induced, highly-selective multiphoton dissociation of C₂TF₅ present in C₂DF₅. Single-step T/D separation factors exceeding 3000, 1000, and 500 were attained, respectively, for the first time with CO₂ laser 10P(34) 931.0 cm^?1 at 10, 20, and 30 Torr pentafluoroethane pressures at ?78 °C (i.e., equivalent to 15, 30, and 45 Torr at room temperature).     

CO2 laser Stark spectroscopy of the Coriolis-coupled ν2 and ν5 bands of CD3Br

The ν₂ (CD₃ symmetrical deformation) and ν₅ (CD₃ degenerate deformation) fundamental bands of CD₃Br were studied by 9.4- and 10.4-μm CO₂ laser Stark spectroscopy. Stark resonances originating from 28 and 53 rovibrational transitions of the ν₂ and ν₅ bands, respectively, were assigned for each of the isotopic species, CD₃⁷⁹Br and CD₃⁸¹Br. These two bands were simultaneously analyzed with explicit inclusion of the ν₂-ν₅ Coriolis interaction, yielding precise molecular constants in the ν₂ and ν₅ excited states as well as the Coriolis coupling constant. The molecular constants obtained are consistent between the two isotopic species and are in good agreement with the results of high-resolution infrared studies. The band origins and dipole moments are

     

10.

A new dual-type DMA for measuring nanoparticles emitted from combustion engines     

Kazuo Takeuchi  Junsuke Yabumoto  Yoshiki Okada  Terunao Kawai  Rahman M. Montajir  Yuichi Goto 《Journal of nanoparticle research》2005,7(2):287-293

A new dual-type differential mobility analyzer (dual-type DMA) was developed in order to detect transient number concentrations of airborne nanoparticles with diameters centralized at around 10 nm (for nuclei mode particles) and 100 nm (for accumulation mode particles) in automobile exhaust gas. The apparatus divides the gas sample into two parts, and each part is sent through one of two coaxially nested sections for analysis. For the scanning mode measurement, the nanoparticles are charged by ²⁴¹Am and their size distributions are determined by varying the applied voltage over 2 min. The transient mode measurement, on the other hand, fixes the voltages for the two sections at peaks near 10 and 100 nm in order to monitor the transient behavior of the exhaust nanoparticles. The measurement principles and design of the dual-type DMA are detailed and the results for time response experiments are presented using model nanoparticles charged by a corona charger. The transient concentrations of the nuclei mode and the accumulation mode particles from a diesel engine were shown to be detected by this method, when ²⁴¹Am was used for charging the particles.     

1 [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] 下一页 » 末  页»

		CD379Br		CD381Br
$\text{ν}{}_2$		991.396 82 (18)		991.388 46 (17)		cm?1
$\text{ν}{}_5$		1055.469 00 (12)		1055.466 32 (12)		cm?1
$\text{μ}{}_0$		1.830 42 (52)		1.829 84 (47)		D
$\text{μ}{}_2$		1.829 93 (48)		1.829 57 (46)		D
$\text{μ}{}_5$		1.832 23 (60)		1.831 19 (56)		D

A new dual-type DMA for measuring nanoparticles emitted from combustion engines

A new dual-type differential mobility analyzer (dual-type DMA) was developed in order to detect transient number concentrations of airborne nanoparticles with diameters centralized at around 10 nm (for nuclei mode particles) and 100 nm (for accumulation mode particles) in automobile exhaust gas. The apparatus divides the gas sample into two parts, and each part is sent through one of two coaxially nested sections for analysis. For the scanning mode measurement, the nanoparticles are charged by ²⁴¹Am and their size distributions are determined by varying the applied voltage over 2 min. The transient mode measurement, on the other hand, fixes the voltages for the two sections at peaks near 10 and 100 nm in order to monitor the transient behavior of the exhaust nanoparticles. The measurement principles and design of the dual-type DMA are detailed and the results for time response experiments are presented using model nanoparticles charged by a corona charger. The transient concentrations of the nuclei mode and the accumulation mode particles from a diesel engine were shown to be detected by this method, when ²⁴¹Am was used for charging the particles.