Microchip Electrophoretic Analyses of Cationic Analytes Using Large-Volume Dual Preconcentration by Isotachophoresis and Stacking (LDIS) – Field-Amplified Sample Injection (FASI) in Y-Form Channels
Chromatography,
Journal Year:
2025,
Volume and Issue:
unknown
Published: April 23, 2025
Language: Английский
Application of on-line sample preconcentration by large-volume dual preconcentration by isotachophoresis and stacking (LDIS) on straight-channel microchips
Analytical Sciences,
Journal Year:
2024,
Volume and Issue:
40(9), P. 1611 - 1617
Published: May 16, 2024
In
this
study,
large-volume
dual
preconcentration
by
isotachophoresis
and
stacking
(LDIS)
which
is
an
on-line
sample
technique
coupling
with
electroosmotic
flow
pump
(LVSEP)
transient
(tITP)
was
applied
to
microchip
electrophoresis
(MCE)
for
improving
both
detection
sensitivities
peak
shapes.
To
realize
LDIS
in
MCE,
we
investigated
experimental
procedures
injecting
a
short
plug
of
leading
electrolyte
(LE)
solution
into
straight
microchannel
without
any
sophisticated
injector
apparatus.
We
found
that
LE
could
be
injected
sample-filled
straight-channel
only
making
the
liquid
level
outlet
reservoir
higher
than
inlet
one.
By
applying
reversed-polarity
voltage
microchip,
anionic
analytes
throughout
were
first
enriched
LVSEP,
followed
tITP.
Through
second
effect
tITP
LDIS,
sensitivity
enhancement
factor
(SEF)
asymmetry
standard
dye
improved
from
878
0.62
1330
1.14,
respectively,
relative
those
conventional
LVSEP.
It
should
noted
more
viscous
running
buffer
containing
sieving
polymers
employed
analysis,
effective
SEF
separation
efficiencies,
especially
bio-polymeric
compounds.
Finally,
oligosaccharide
protein
analyses
resulting
SEFs
1410
ca.
50
maltotriose
bovine
milk
casein,
respectively.
Language: Английский
Combination of on-line sample preconcentration by large-volume dual preconcentration by isotachophoresis and stacking (LDIS) with field-amplified sample injection (FASI) on Y-channel microchips
Analytical Sciences,
Journal Year:
2024,
Volume and Issue:
40(12), P. 2117 - 2124
Published: Aug. 20, 2024
In
our
previous
study,
the
combination
of
two
on-line
sample
preconcentration
techniques,
large-volume
stacking
with
an
electroosmotic
flow
(EOF)
pump
(LVSEP)
and
transient
isotachophoresis
(tITP),
in
microchip
electrophoresis
(MCE)
was
developed,
which
named
dual
by
(LDIS).
LDIS
apparently
effective
for
improving
sensitivity
peak
shape.
LDIS,
however,
there
a
limit
to
improvement
enhancement
factor
(SEF)
since
amount
analytes
be
concentrated
limited
channel
volume.
To
overcome
this
issue,
present
article,
coupled
field-amplified
injection
(FASI)
technique
on
Y-shaped
microchips.
The
use
Y-channel
LDIS-FASI
allowed
consecutive
LVSEP,
FASI
tITP
enrichments
simple
voltage
control.
conventional
LVSEP
analyses
standard
analyte,
SEFs
were
evaluated
2630
13,100,
respectively,
whereas
that
increased
27,900
even
at
time
0
s.
achieve
higher
SEFs,
furthermore,
150
s,
resulting
best
SEF
58,500.
It
should
emphasized
width
quite
narrow,
only
0.3–3.1
while
normal
13
Furthermore,
applied
analysis
oligosaccharide
mixture.
Due
focusing
effect
LDIS-FASI,
resolutions
improved
from
0.97–1.57
2.08–2.73.
Language: Английский