• 13 •
800-356-1688 •
2004vol. 3
MakeGC/MSColumnChanges inMinutes
WithoutVenting
EZNo-Vent
™
Connector Allows Fast Re-equilibrationwithNo Loss of Data
A lasermachined critical orifice in the EZNo-
Vent
™
connectorminimizes the amount of air
admitted into theMS source, eliminating the
need for purge gas and for the lengthy vent and
pump-down cycle otherwise requiredwith a col-
umn change.This can save hours of downtime
with each column change.The EZNo-Vent
™
con-
nector easily attaches to theMS sourcewithout
special tools or extra plumbing: Figure 1 shows
the connector installed and ready for use.
We tested the EZNo-Vent
™
connector for dead
volume, using highly volatile gases that are very
susceptible to tailing. For reference, we operat-
ed the system as a purge-and-trapGC/MS sys-
tem, with a split at the injection port andwith
the column inserted directly into theMS inter-
face.Whenwe installed the EZNo-Vent
™
connec-
tor in theMS interface, we anticipated that any
dead volume in the connector would be revealed
by tailing and broader peaks, relative to direct
connection. Peak shapewas excellent.
After establishing the connector had no effect
on peak shape, we evaluated the ability of the
MS to stabilize after a column changewithout
venting. Againwe used a purge-and-trap sys-
tem, and halogenated volatiles as the analytes.
We acquired Figure 2a, changed the column,
and acquired Figure 2b 76minutes later. Note
the peak shapes and responses are unchanged.
In the interval between the two analyseswe
verifiedMSD tuning, and the system passed bro-
mofluorobenzene (BFB) criteria. Subsequent
detailed investigations confirmed the EZNo-
Vent
™
connector will allow several column
changes in a single day, with no harm to theMS
or loss of data.
If you're tired of waiting for yourMS to stabilize
after column changes, we highly recommend an
EZNo-Vent
™
connector. It will greatly reduce
downtime and increase sample throughput.
by Brad Rightnour, Instrument InnovationsManager,
and Christopher English, Environmental Innovations Chemist
•Cut downtime by 50% ormorewhen changing columns.
•No special tools - no extra plumbing - low cost.
•Gold plated for inertness.
•100µm ID transfer line keeps analytes focused.
a)
First column, equilibrated system
b)WithEZNo-Vent™connector, acquired76min.
after installingnewcolumn
Figure2
Sampleacquiredwithinanhour andahalf after changing columns, usinganEZNo-Vent™ connector.
Figure1
MS transfer line installed inan
EZNo-Vent™ connector. Connection canbe
madequickly,without special tools.
EZNo-Vent
™
GCColumn-MassSpectrometerConnector
Description
qty.
cat.#
price
EZNo-Vent
™
Connector Kit for Agilent 5971/5972 and 5973GC/MS
Kit includes: EZNo-Vent
™
Connector, two 0.4mm ID ferrules for capillary col-
umn, two 0.4mm ID ferrules for transfer line, 100µm deactivated transfer line
(3 ft.), column plug, column nut.
kit
21323
$175
Replacement ferrules for connecting capillary column to EZNo-Vent
™
:
0.4mm ID
2-pk.
21015
$28
0.5mm ID
2-pk.
21016
$28
Replacement ferrules for connecting transfer line to EZNo-Vent
™
: 0.4mm ID
2-pk.
21043
$25
Replacement 100µmdeactivated transfer line
3 ft.
21018
$20
Replacement EZNo-Vent
™
ColumnNut
5-pk.
21900
$30
Replacement EZNo-Vent
™
Plug
2-pk.
21915
$36
Open-EndWrenches (
1
/
4
" x
5
/
16
")
2-pk.
20110
$25
5 6
4 3
7 8 9 10 11 12 13 14 15 16 17 18 19
min.
20
Conditions forbothchromatograms:
Rtx
®
-624 column, 60m, 0.25mm ID, 1.4µm (cat# 10969) using
Ez-No Vent
™
, column #1, equilibrated system.
Halogenated Volatiles@ 200 ppb inwater.
Inj.:
purge& trap
Inj. temp.:
300°C
Carrier gas:
helium, constant flow, 1.0mL/min.
Oven temp.:
60°C (hold 15min) to 220°C@ 30°C/min. (hold 1min).
Det:
Agilent 5973GC/MS
GC_EV00659c
3 4 5 6 7 8 9 10 11 12
20 min.
13 14 15
19 18 17 16
GC_EV00659d
Restek offers supplies
and innovative tools
for yourMS. Refer to
our general catalog.
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know
?
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Innovation
!
