著者

Lee Chuin Chen Kentaro Yoshimura Satoshi Ninomiya Sen Takeda Kenzo Hiraoka

出版者

The Mass Spectrometry Society of Japan

雑誌

Mass Spectrometry (ISSN:2187137X)

巻号頁・発行日

vol.6, no.3, pp.S0070-S0070, 2017-08-25 (Released:2017-08-23)

参考文献数

42

被引用文献数

2

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In this paper, we briefly review the remote mass spectrometric techniques that are viable to perform “endoscopic mass spectrometry,” i.e., in-situ and in-vivo MS analysis inside the cavity of human or animal body. We also report our experience with a moving string sampling probe for the remote sample collection and the transportation of adhered sample to an ion source near the mass spectrometer. With a miniaturization of the probe, the method described here has the potential to be fit directly into a medical endoscope.

著者

Dilshadbek Tursunbayevich Usmanov Satoshi Ninomiya Lee Chuin Chen Subhrakanti Saha Mridul Kanti Mandal Yuji Sakai Rio Takaishi Ahsan Habib Kenzo Hiraoka Kentaro Yoshimura Sen Takeda Hiroshi Wada Hiroshi Nonami

出版者

The Mass Spectrometry Society of Japan

雑誌

Mass Spectrometry (ISSN:2187137X)

巻号頁・発行日

vol.6, no.2, pp.S0059-S0059, 2017-02-24 (Released:2017-02-24)

参考文献数

89

被引用文献数

9

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In mass spectrometry, analytes must be released in the gas phase. There are two representative methods for the gasification of the condensed samples, i.e., ablation and desorption. While ablation is based on the explosion induced by the energy accumulated in the condensed matrix, desorption is a single molecular process taking place on the surface. In this paper, desorption methods for mass spectrometry developed in our laboratory: flash heating/rapid cooling, Leidenfrost phenomenon-assisted thermal desorption (LPTD), solid/solid friction, liquid/solid friction, electrospray droplet impact (EDI) ionization/desorption, and probe electrospray ionization (PESI), will be described. All the methods are concerned with the surface and interface phenomena. The concept of how to desorb less-volatility compounds from the surface will be discussed.

著者

Yuki Yamada Satoshi Ninomiya Kenzo Hiraoka Lee Chuin Chen

出版者

The Mass Spectrometry Society of Japan

雑誌

Mass Spectrometry (ISSN:2187137X)

巻号頁・発行日

vol.5, no.2, pp.S0068-S0068, 2017-04-18 (Released:2017-04-27)

参考文献数

23

被引用文献数

5

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We report on combining a self-aspirated sampling probe and an ESI source using a single metal capillary which is electrically grounded and safe for use by the operator. To generate an electrospray, a negative H.V. is applied to the counter electrode of the ESI emitter to operate in positive ion mode. The sampling/ESI capillary is enclosed within another concentric capillary similar to the arrangement for a standard pneumatically assisted ESI source. The suction of the liquid sample is due to the Venturi effect created by the high-velocity gas flow near the ESI tip. In addition to serving as the mechanism for suction, the high-velocity gas flow also assists in the nebulization of charged droplets, thus producing a stable ion signal. Even though the potential of the ion source counter electrode is more negative than the mass spectrometer in the positive ion mode, the electric field effect is not significant if the ion source and the mass spectrometer are separated by a sufficient distance. Ion transmission is achieved by the viscous flow of the carrier gas. Using the present arrangement, the user can hold the ion source in a bare hand and the ion signal appears almost immediately when the sampling capillary is brought into contact with the liquid sample. The automated analysis of multiple samples can also be achieved by using motorized sample stage and an automated ion source holder.

著者

Lee Chuin Chen

出版者

The Mass Spectrometry Society of Japan

雑誌

Mass Spectrometry (ISSN:2187137X)

巻号頁・発行日

vol.8, no.2, pp.S0079, 2019-08-26 (Released:2019-08-26)

参考文献数

87

被引用文献数

7

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Increasing the operating temperature of the liquid chromatography (LC) column has the same effect as reducing the diameter of the packing particles on minimizing the contribution of C-term in the van Deemter equation, flattening the curve of plate height vs. linear velocity in the high-speed region, thus allowing a fast LC analysis without the loss of plate count. While the use of smaller particles requires a higher pumping pressure, operating the column at higher temperature reduces the pressure due to lower liquid viscosity. At present, the adoption of high-temperature LC lags behind the ultra-high-pressure LC. Nevertheless, the availability of thermally stable columns has steadily improved and new innovations in this area have continued to emerge. This paper gives a brief review and updates on the recent advances in high-temperature liquid chromatography (HTLC). Recent efforts of hyphenating the capillary HTLC with mass spectrometry via a super-atmospheric pressure electrospray ionization is also reported.