14
1.90 2.00 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90 3.00 3.10 3.20 3.30 3.40 3.50 3.60 3.70
Figure 9.
MS scan rate adjusted to detect methanol and show the region
wheremethanol elutes from anRtx
®
-VMS column.
Figure 10.
AnMCS bypass line can increase response andmaintain
linearity for ketones, alcohols, and acetates.
disconnected
MCS line
top of trap
Transfer Line
Once the sample is desorbed from the trap, it travels through the heated transfer line to the
GC. This line can bemade of nickel, fused silica, or Silcosteel
®
-treated tubing.A heating
jacket surrounds the transfer line to keep it between 120-125°C, which preventswater and
analyte condensation in the line. For direct connection, we recommendmatching the inside
diameter of the transfer line to the inside diameter of the capillaryGC column, or use of tub-
ing of a slightly smaller inner diameter than the capillary column. This helpsminimize band
broadening and poor peak symmetry for sample components. Because transfer lines can be a
source of active sites, use deactivated fused silica or Silcosteel
®
-treated tubing to reduce ana-
lyte adsorption.When using a fused silica transfer line, insert the line into ametal tube
before installing it into the heated jacket. Thiswill protect the fused silica tubing from nicks
and scratches that could cause the line to break. Be sure to use the correctValco
®
ferrules to
minimize dead volume (seeDirect Connection, page 20).
1
2
3
4
5
1. difluorodichloromethane
2. chloromethane
3. vinyl chloride
4. bromomethane
5. chloroethane
6. trichlorofluoromethane
EPAMethod 8260, Rtx
®
-VMS column, 30m, 0.25mm ID,
1.40µm (cat.# 19915)
Carrier gas:
1.3mL/min.@ constant flow
GC:
HP6890
Detector:
HP5973MSD
Oven temp.:
45°C (ISD)
MS scan range:29-260amu
methanol
CO
2
MCS
min.
bypass line
MoistureControl Bypass Line for
Tekmar 3000Purge& Trap
• Increases response for ketones, alcohols, and acetates.
• Suitable for USEPAMethods 8260, 524.2, andOLM4.1.
• Silcosteel
®
tubing for increased inertness.
• Easily attaches inminutes.
Description
qty.
cat.#
Moisture Control Bypass Line
ea.
21035
1.90 2.00 2.10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90 3.00 3.10 3.20 3.30 3.40 3.50 3.60 3.70
6
