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Volume 65, Issue 1
Displaying 1-5 of 5 articles from this issue
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Annual Topic “Transcendence” : Accounts
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Katsumi UCHIYAMAArticle type: Annual Topic “Transcendence” : Accounts
2016 Volume 65 Issue 1 Pages 1-11
Published: January 05, 2016
Released on J-STAGE: February 06, 2016
JOURNAL FREE ACCESSWe have developed an ultra-small sample introduction (pL–nL) method using an ink-jet. This method enables a precise ejection of the sample amount, the position of deposition and the velocity for the ejected droplets. This paper describes the driving method and the basic characteristics of the inkjet. Then, the sample introduction method is described for gas chromatography and capillary electrophoresis based upon our reported work.View full abstractDownload PDF (1294K)
Accounts
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Shigehiro KAGAYAArticle type: Accounts
2016 Volume 65 Issue 1 Pages 13-23
Published: January 05, 2016
Released on J-STAGE: February 06, 2016
JOURNAL FREE ACCESSCoprecipitation is one of the most useful methods for the separation and preconcentration of trace elements. In this method, a carrier element is precipitated by using an appropriate precipitant in a solution, and trace elements in this solution are coprecipitated along with the precipitate (so-called coprecipitant). The precipitate has to be completely collected; however, the operation is tedious and time-consuming. To overcome this weak point, a rapid coprecipitation technique, which does not require the quantitative recovery of the precipitate, has been developed. In this technique, any trace elements coprecipitated can be determined based on internal standardization using carrier element as an internal-standard element, because loss of the precipitate can be estimated by the difference in the amount of the carrier element before and after coprecipitation. The carrier element used for this technique has to satisfy the following requirements: 1) negligible content of the carrier element in samples, 2) quantitative precipitation of the carrier element, 3) quantitative coprecipitation of trace elements with the precipitate containing the carrier element, 4) easy determination of the carrier element, 5) correlation between the amount of loss of the carrier element and that of the trace elements after coprecipitation, 6) no interference in the determination of trace elements by the carrier element. The other element, which can be quantitatively coprecipitated with the precipitate, is also used as the internal-standard element. The operation of the precipitate recovery in the rapid coprecipitation technique is simple and rapid compared with that in the conventional coprecipitation method. This paper describes the principle of the rapid coprecipitation technique and its application for the separation and preconcentration of trace elements.View full abstractDownload PDF (944K) -
Ikuo UETA, Yoshihiro SAITOArticle type: Accounts
2016 Volume 65 Issue 1 Pages 25-32
Published: January 05, 2016
Released on J-STAGE: February 06, 2016
JOURNAL FREE ACCESSA novel purge-and-trap (PT) method for the determination of volatile organic compounds (VOCs) in aqueous samples was developed by using a needle-type extraction device. With a simple active sampling of head-space gas, the target analytes could be extracted on the extraction medium, which was packed in the stainless-steel needle. The analytes were thermally desorbed in a conventional gas chromatographic injector by direct insertion of the extraction needle. The proposed PT extraction method does not require any expensive instrumentation for sample preparation. This review summarizes recent applications of the needle-type extraction device for the PT extraction of several VOCs in aqueous samples, such as the determination of 23 VOCs, musty odor compounds and very volatile organic compounds. In addition, the proposed PT method was applied to the determination of aqueous formaldehyde using an extraction capillary in high-performance liquid chromatographic analysis. The extraction capillary was prepared by packing silica-gel particles in a stainless-steel capillary. After the impregnation of a derivatization reagent on the silica-gel particles, derivatization and concentration of aqueous formaldehyde were achieved by PT sampling. By direct connection of the extraction capillary to a six-port valve, a rapid and simple desorption of the derivative was accomplished.View full abstractDownload PDF (751K)
Research Papers
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Masashi SUZUKI, Toshiyuki MIYAUCHI, Yuya MIZUNO, Norihisa ISHIKAWAArticle type: Research Papers
2016 Volume 65 Issue 1 Pages 33-38
Published: January 05, 2016
Released on J-STAGE: February 06, 2016
JOURNAL FREE ACCESSA weakly acidic cation-exchanger based on kenaf were prepared, and the adsorption of copper ion and platinum-group metal ions on the cation-exchanger were studied. The kenaf was pretreated with concentrated hydrochloric acid at about 100°C for 2 hour. Next, the reducing terminal group (aldehyde group) formed by the hydrolysis of cellos in kenaf was oxidized with solid potassium permanganate to give a weakly acidic cation-exchanger with a carboxyl group. The adsorption capacity was 2.80 Cu(II) meq g−1– R. The optimum pH range for the adsorption of Cu(II) was more than about 2.5. The adsorption was rapid and the adsorption equilibrium was attained within about 30 min. Thus, the synthesized exchanger could be used in a column with a high flow rate. Cu(II), and only Ru(III), Rh(III) and Pd(II) among the platinum-group metal ions were adsorbed on a synthesized exchanger. The Cu(II) and above platinum-group metal ions loaded on a synthesized exchanger were separated from each other by elution with a 0.05 – 1.0 mol L−1 hydrochloric acid solution, such as Cu(II) – Pd(II) – Ru(III) and Cu(II) – Rh(III) – Ru(III). Furthermore, the recoveries of Cu(II) and platinum-group metal ions contained in a laptop board were also investigated.View full abstractDownload PDF (829K) -
Kazuko YAMASHITA, Tatsuo NAKADA, Hideya KAWASAKI, Ryuichi ARAKAWAArticle type: Research Papers
2016 Volume 65 Issue 1 Pages 39-43
Published: January 05, 2016
Released on J-STAGE: February 06, 2016
JOURNAL FREE ACCESSThe method for the quantitative analysis of fluoride anion employs a color change from purple-red to violet under the reaction of La(III)-alizarin-complexone(ALC) with the fluoride anion. We investigated the chemical species in a La(III)-alizarin-complexone(ALC) solution as well as its reaction solution with fluoride anion by using high-resolution mass spectrometry. As a result, the complexes present in a La(III)-(ALC) solution were estimated to be (La-ALC)4–6, and their structure was an annulation consisting of (La-ALC) units. In these three complexes, only the (La-ALC)4 complex reacted with fluorine ions to produce deprotonated complexes of [(La-ALC)4-H + LaF2] and [(La-ALC)4-2H + LaF]. This deprotonation of (La-ALC)4 caused the solution to vary from purple-red to violet. (La-ALC)5–6 complexes were not detected in a solution with excessive fluorine ions. This is because (La-ALC)4 decreasing with complexation with the fluorine ions is thought to be supplied from the degradation of (La-ALC)5–6. The same results were obtained in the system of Ce(III).View full abstractDownload PDF (989K)
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