Visualization of volatile substances in different organelles with an atmospheric-pressure mass microscope.
We have developed a mass microscope (mass spectrometry imager with spatial resolution higher than the naked eye) equipped with an atmospheric pressure ion-source chamber for laser desorption/ionization (AP-LDI) and a quadrupole ion trap time-of-flight (QIT-TOF) analyzer. The optical microscope combined with the mass spectrometer permitted us to precisely determine the relevant tissue region prior to performing imaging mass spectrometry (IMS). An ultraviolet laser tightly focused with a triplet lens was used to achieve high spatial resolution. An atmospheric pressure ion-source chamber enables us to analyze fresh samples with minimal loss of intrinsic water or volatile compounds. Mass-microscopic AP-LDI imaging of freshly cut ginger rhizome sections revealed that 6-gingerol ([M + K](+)at m/z 333.15, positive mode; [M - H](-) at m/z 293.17, negative mode) and the monoterpene ([M + K](+) at m/z 191.09), which are the compounds related to pungency and flavor, respectively, were localized in oil drop-containing organelles. AP-LDI-tandem MS/MS analyses were applied to compare authentic signals from freshly cut ginger directly with the standard reagent. Thus, our atmosphere-imaging mass spectrometer enabled us to monitor a quality of plants at the organelle level.
Harada
Takahiro
T
Technology Research Laboratory, Shimadzu Corporation, 3-9-4 Soraku-gun, Seika-cho, Kyoto 619-0237, Japan.
Yuba-Kubo
Akiko
A
Sugiura
Yuki
Y
Zaima
Nobuhiro
N
Hayasaka
Takahiro
T
Goto-Inoue
Naoko
N
Wakui
Masatoshi
M
Suematsu
Makoto
M
Takeshita
Kengo
K
Ogawa
Kiyoshi
K
Yoshida
Yoshikazu
Y
Setou
Mitsutoshi
M
D001274:Atmospheric Pressure; D002396:Catechols / Q000032:analysis; D005233:Fatty Alcohols / Q000032:analysis; D020939:Zingiber officinale / Q000737:chemistry; D039821:Monoterpenes / Q000032:analysis; D053719:Tandem Mass Spectrometry / Q000295:instrumentation* / Q000379:methods; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000737:chemistry
D002396:Catechols; D005233:Fatty Alcohols; D039821:Monoterpenes; D055549:Volatile Organic Compounds; C007845:gingerol