巻号一覧
44 巻 (1996)
- 6 号 p. 563-
- 5 号 p. 501-
- 4 号 p. 461-
- 3 号 p. 293-
- 2 号 p. 105-
- 1 号 p. 1-
44 巻, 4 号
選択された号の論文の4件中1～4を表示しています
- |<
- <
- 1
- >
- >|
報文
-
Kohichi KOTAKI, Tatsuo ARIKAWA1996 年 44 巻 4 号 p. 461-472
発行日: 1996年
公開日: 2007/07/20
ジャーナル フリーAn attempt was made to enhance the Lyman-α emission for the detection of low energy atomic hydrogen beams diffracted from the surface by means of (1+2) resonantly enhanced multiphoton ionization (REMPI). Employing a Kr-Ar mixing cell, the efficiency of frequency tripling to generate the vacuum ultraviolet (VUV) emission around the Lyman α line was fairly enhanced by about one order of magnitude compared to that with an ordinary pure Kr cell. An ionization chamber filled with acetone was also investigated for the detection and monitoring of the VUV light. Monochromatic atomic hydrogen (H) beams were prepared either via photodissociation of hydrogen-bromine (HBr) molecules at 243 nm with de Broglie wavelengths of 0.31Å and 0.25Å, or via photodissociation of hydrogen-iodine (HI) molecules at 266 nm with de Broglie wavelengths of 0.35Å an 0.23Å, respectively. Employing these H-beams, feasibilities for detection and visualization of diffraction patterns from the surface by the use of a fast optical imaging system were investigated by means of computer simulation experiments.抄録全体を表示PDF形式でダウンロード (806K) -
Mitsuo TAKAYAMA, Toshiyuki KOSAKA, Takeshi KINOSHITA1996 年 44 巻 4 号 p. 473-481
発行日: 1996年
公開日: 2007/07/20
ジャーナル フリーFormation of the [M-H]+ ions of Trolox and α-tocopherol produced under fast atom bombardment (FAB) conditions has been examined by using collision-induced dissociation (CID) technique with tandem mass spectrometry. The CID spectra of the [M-H]+ ions of these compounds have been compared with those of the M+· and [M+H]+ ions. The CID spectra of the [M-H]+, M+·, and [M+H]+ ions of Trolox showed characteristic ion peaks at m/z 163, 164, and 165, respectively, whereas the CID spectra of the [M-H]+, M+·, and [M+H]+ ions of α-tocopherol showed a common peak at m/z 165 which comes from an intramolecular hydrogen rearrangement reaction, despite a common structure unit corresponding to those fragment ions. In order to explain the results obtained, possible structures of the [M-H]+ ions of Trolox and α-tocopherol would be presented though the site(s) of a hydrogen loss from analytes could not be determined. The structure characteristics of analytes and the mechanism to form [M-H]+ ions under matrix FAB conditions have been discussed, and it has been concluded that the formation of molecular-related ions [M-H]+, M+·, and [M+H]+ occurs competitively according to the nature of analyte and matrix molecules under matrix FAB conditions.抄録全体を表示PDF形式でダウンロード (534K) -
Yukio YOKOYAMA, Yoshiyuki MOCHIDA, Toshinaga KAWAI, Shigeo NAKAMURA, M ...1996 年 44 巻 4 号 p. 483-491
発行日: 1996年
公開日: 2007/07/20
ジャーナル フリーEffects of additives, introduced to a sample through vapor phase, on the formation of protonated molecules and/or molecular adduct ions were investigated in liquid ionization mass spectrometry for the analysis of methyl hydroperoxyoleates. Water and formic acid having small proton affinities were useful for increasing ion abundance of protonated molecules [M+H]+. 2-Aminoethanol and pyridine having slightly greater proton affinities were useful for forming molecular adduct ions [M+H+L]+ (L: additive molecule). The use of additives, acting as matrix for producing [M+H]+ and/or as reagent for forming [M+H+L]+ in liquid ionization mass spectrometry, provided useful mass spectral characteristics of the molecular weight and structure of unknown compounds.抄録全体を表示PDF形式でダウンロード (516K)
ノート
-
高山 光男, 高橋 利枝1996 年 44 巻 4 号 p. 493-497
発行日: 1996年
公開日: 2007/07/20
ジャーナル フリーA criterion for the choice of liquid matrix in fast atom bombardment mass spectrometry (FAB-MS) has been presented. The results obtained from the criterion indicated that suitable matrices for positive-ion FAB are thioglycerol (TG), dithiothreitol (DTT), and m-nitrobenzyl alcohol (NBA) and those for negative-ion FAB are triethanolamine (TEA) and diethanolamine (DEA). Further, the criterion proposed that glycerol (G) is a suitable matrix material for both positive and negative-ion modes. These indications were in good agreement with the empirical facts.抄録全体を表示PDF形式でダウンロード (431K)
- |<
- <
- 1
- >
- >|