  The extremely thin atmosphere of Jupiter's volcanic moon Io primarily
consists of sulfur (S), sodium (Na), and oxygen (O) molecules that are
controlled by the combination of the sublimation and volcanic outgasses. We
present the first spectroscopic detection of the two rotational emission lines
of acetone (CH$_{3}$COCH$_{3}$) and a single emission line of disulfur monoxide
(S$_{2}$O), and carbon monoxide (CO) at frequency $\nu$ = 346.539, 346.667,
346.543, and 345.795 GHz respectively using the archival data of
high-resolution Atacama Large Millimeter/Submillimeter Array (ALMA)
interferometer with band 7 observation. All molecular species are detected with
$\ge$5$\sigma$ statistical significance. Jupiter's moon Io is the most
volcanically active body in the solar system with a very thin and spatially
variable atmosphere. The volcanic gas CH$_{3}$COCH$_{3}$, S$_{2}$O, and CO are
mainly coming from volcanic plumes. The statistical column density of
CH$_{3}$COCH$_{3}$ line is N(CH$_{3}$COCH$_{3}$) = 3.18$\times$10$^{15}$
cm$^{-2}$ but for the cases of S$_{2}$O and CO, the column densities are
N(S$_{2}$O) = 2.63$\times$10$^{16}$ cm$^{-2}$ and N(CO) = 5.27$\times$10$^{15}$
cm$^{-2}$ respectively. The carbon monoxide gas is mainly formed by the
photolysis of the volcanic gas acetone.
