Low-Bleed Column,
NewReferenceMixes for
Semivolatile Organic Analytes
in DrinkingWater
UsingGas Chromatography/Mass
Spectrometry (EPAMethod 525.2)
the
800-356-1688
★
814-353-1300
2003
vol.3
Advantage
Innovators of HighResolution
Chromatography Products
in this issue
By Christopher English, Environmental Innovations Chemist &KatiaMay, Ph.D., R&DChemist
Rtx
®
-5Sil MS column provides:
✔
extremely low bleed, for greater sensitivity in GC/MS applications.
✔
excellent resolution of 110 target semivolatile compounds in
EPAMethod 525.2.
EPA 525.2 referencematerials are:
✔
economical— calibrationmixtures at 1000µg/mL concentration, for more
analyses per ampul.
✔
convenient— 106 compounds in only sixmixtures.
✔
calibrationmixtures formulated by chemical class: semivolatiles, PCB
congeners, organochlorine pesticides, nitrogen/phosphorus pesticides.
✔
six nitrogen/phosphorus pesticides in a separatemix, for stability.
Gas chromatographic analyses for semivolatile ana-
lytes in drinkingwater require an inert, thermally
stable, low-bleed stationary phase. EPAMethod 525,
a liquid-solid extraction / capillary GC/MS analysis, is
applicable formonitoring awide range of semi-
volatiles in an aqueousmatrix. The new revision,
Method525.2, includes 110 target compounds.
Restekprovides thematerials needed for this analysis:
extractiondisks, referencematerials, and an inert
column capable of excellent response for acids and
bases, even at single digit nanogramon-column
quantities.
Of the EPAGC/MSmethods for analyz-
ing semivolatiles, Method 525.2 is
themost demanding for column
inertness. Method 525.2 target
analytes includemany active
compounds, e.g., endrin,
methoxychlor, DDT, pen-
tachlorophenol. Simple
adjustments to the
injection conditions
can yield great
improvements in
sensitivity, especially for active and highmolecular
weight compounds. Analytes can degrade in the
injection port and exhibit excessive tailing. To pre-
vent this, we use aDrilledUniliner
®
inlet liner: a
Press-Tight
®
seal between the fused silica column
and the internal surface of the liner eliminates con-
tact between the sample and the hot metal surfaces
in the injection port. A pulsed injection (30psi, 0.5
min.) reduces the time the analytes spend in the
injection port, and helps tominimize breakdown.
Pulsed pressure injection increases the possibility of
breaking the seal between the column and the liner.
Therefore, head pressure should not exceed 50psi
when using the pulsed splitlessmode. A starting
temperature of 35°C helps ensure excellent peak
shapes for early eluting target analytes.
To reduce bleed and activity, Restek continues to
explore new synthesis routes for both column
deactivation and the stationary phase polymer.
Improvements in technology allow our Rtx
®
-5Sil MS
columns towithstand high bake-out temperatures
without loss of deactivation. The inset in Figure 1 is
an example of superior efficiency and low bleed for
amid-point standard, at 330°C. Peak shape and
Low-BleedGCColumn,
NewReferenceMixes
for SemivolatileOrganics
inDrinkingWater
pages 1-3
Verify Fruit JuiceQuality
fromOrganicAcidProfiles,
UsingHPLC
pages 4-5
Special-PurposeHPLCColumn
for PAHs
page 5
NewMegaMix
™
ReferenceMixes
for OLC03.2Statement ofWork
pages 6-7
SemivolatilesReferenceMix for
Wastewater Analysis byGC/MS
pages 8-9
Rtx
®
-5SilMSColumns
page 9
HighlyBase-DeactivatedHPLC
Columns
page 10
MiniatureAir Sampling
Cylinders
page 11
NewReferenceMaterials for
PurgeandTrap, Environmental,
ForensicsApplications
page 11
TO-Can
™
Canisters
for Air Sampling
page 12
SilcoCan
™
Canisters
for Air Sampling
page 13
PeakPerformers
page 14
Cool Tools
page 15
STARService
RewardsProgram
page 16
