Catalpol (4): UV [[lambda].sub.max] (MeOH) nm 208 nm, IR (KBr) [v.sub.max] 3450 (OH), 1670 (C=C) [cm.sup.-1],
Positive ion LC-ESIMS m/z 385 [[M+Na].sup.+] (calc.
It is observed that the linearity of ginsenosides detected in the negative ion mode was better than that in the
positive ion mode.
Specifically, Calcote and King considered only
positive ions and electrons in their equilibrium calculations (produced by thermal ionization).
All the fragmentations of cellulose are present and the base peak of fragmentation appears at m/e 76 due to
positive ion or free radical
positive ion of CS2.
Since ceramides in
positive ion mode MS/MS generate characteristic product ions of m/z 264 and 282, precursor ion scans of m/z 264 and m/z 282 were used for detecting ceramides in the adipose tissue.
Another one was stimulated by the same iontophoretic device, but the two electrodes were put in opposite positions than the previously discussed one for
positive ion stimulation.
Subscripts i = n and i = p appear for negative and
positive ions respectively.
If the potential is too low the
positive ions and the free electrons will recombine before they reach the anode.
These electrons can be excited to higher energy levels, and at appropriate electron beam energies, the atom can lose that electron producing a
positive ion. These ejected electrons are known as secondary electrons.
The
positive ion density was a moderate 2,700/[cm.sup.3] and the negative ion density was 2,400/[cm.sup.3].
He suggested that dissolved electrolytes were indeed completely dissociated in solution but that each
positive ion was attended by a cloud of negative ions, while each negative ion was attended by a cloud of
positive ions.
Positive ions are arranged in different geometries around DNA and RNA: in so-called site-bound or contact-pair geometries, a
positive ion is located in direct contact with an oxygen atom of a phosphate group.
