Terufumi Fujiwara

Sensitive determination of bromine and iodine in aqueous and biological samples by electrothermal vaporization inductively coupled plasma mass spectrometry using tetramethylammonium hydroxide as a chemical modifier

A procedure for the simultaneous determination of bromine and iodine by inductively coupled plasma (ICP) mass spectrometry was investigated. In order to prevent the decrease in the ionization efficiencies of bromine and iodine atoms caused by the introduction of water mist, electrothermal vaporization was used for sample introduction into the ICP mass spectrometer. To prevent loss of analytes during the drying process, a small amount of tetramethylammonium hydroxide solution was placed as a chemical modifier into the tungsten boat furnace. After evaporation of the solvent, the analytes instantly vaporized and were then introduced into the ICP ion source to detect the (79)Br(+), (81)Br(+), and (127)I(+) ions. By using this system, detection limits of 0.77 pg and 0.086 pg were achieved for bromine and iodine, respectively. These values correspond to 8.1 pg mL(-1) and 0.91 pg mL(-1) of the aqueous bromide and iodide ion concentrations, respectively, for a sampling volume of 95 microL. The relative standard deviations for eight replicate measurements were 2.2% and 2.8% for 20 pg of bromine and 2 pg of iodine, respectively. Approximately 25 batches were vaporizable per hour. The method was successfully applied to the analysis of various certified reference materials and practical situations as biological and aqueous samples. There is further potential for the simultaneous determination of fluorine and chlorine.

Direct determination of bromine in plastics by electrothermal vaporization/inductively coupled plasma mass spectrometry using a tungsten boat furnace vaporizer and an exchangeable sample cuvette system

A tungsten boat furnace vaporization inductively coupled plasma mass spectrometry (TBF/ICP-MS) method has been applied to the direct determination of bromine in plastic samples. In the pretreatment, the plastic sample is spread over a small sample cuvette made of tungsten by treating it with a strongly basic organic solution, e.g., octanol or diisobutyl ketone in the presence of potassium hydroxide. The cuvette is placed on a tungsten boat furnace, with which the electrothermal vaporizer is equipped. At the vaporization step, a widely spread thin layer of the sample facilitates its efficient evaporation and introduction into an ICP mass spectrometer. The most remarkable feature is that all the bromine species in plastic samples are decomposed to form a thermally stable inorganic salt during the pretreatment procedure. Therefore, the bromine content in plastic samples can be measured by a calibration curve method constructed with an aqueous standard solution of potassium bromate(V). The detection limit (3sigma) was estimated to be 0.77 pg of bromine, which corresponds to a concentration of 0.31 ng g(-1) of bromine in plastic samples when a sample amount taken of 2.5 mg is studied. The relative standard deviation was calculated to be 2.2%. Analytical results of some plastic samples, which contained both inorganic bromide salts and also organic bromine species, are given.

Magnetic drop-in tungsten boat furnace vaporisation inductively coupled plasma atomic emission spectrometry (MDI-TBF-ICP-AES) for the direct solid sampling of iron and steel

Focusing on the significant difference of vaporisation properties between analytes and matrix iron as well as taking advantage of the properties that magnets attract iron, a magnet hanging sample introduction system for the tungsten boat furnace vaporisation ICP atomic emission spectrometric determination of trace elements (S, Se, Sb) in iron and steel samples has been developed.

Direct determination of bismuth in steel samples by magnetic drop-in electrothermal vaporization inductively coupled plasma atomic emission spectrometry.

YASUAKI OKAMOTO, KEISUKE YAMAMOTO, HIROKO KATAOKA, SATOSHI TSUKAHARA, TERUFUMI FUJIWARA,* HIROSHI UCHIHARA, MASAHIKO IKEDA, BUNJI HASHIMOTO, and KAZUAKI WAGATSUMA Department of Chemistry, Graduate School of Science, Hiroshima University, Kagamiyama, Higashihiroshima 739-8526, Japan; Horiba Analytical Application Center, Miyanohigashi, Kisshoin, Minami-Ku, Kyoto 601-8510, Japan; Institute for Materials Research, Tohoku University, Katahira, Aoba-Ku, Sendai, 980-8577, Japan

In situ measurements of emission transition dipole moment of individual ordered microdomain of diprotonated tetraphenylporphine aggregate formed at dodecane/aqueous H2SO4 interface.

Rhombic-ordered microdomains of diprotonated 5,10,15,20-tetraphenylporphine aggregate, whose sizes were 10–200u2009µm, were formed at dodecane/aqueous H2SO4 interfaces. The light excitation of their two absorption bands (410 and 473xa0nm for H- and J-bands, respectively) led to one fluorescence band at longer wavelength (723xa0nm). The direction of the emission transition dipole moment (µe) of individual rhombic microdomains, determined with an in situ optical microscope and a linear polarizer, was almost parallel to the major axis, which was also almost parallel to the direction of the absorption transition dipole moment of their J-bands. Their absorption and emission transition scheme was proposed.