A59
AutoProbe
TM
A
technique is of little use if "cross contamination" or
"memory effects" occur during sample analysis. This
problem does not occur in the AutoProbe because the
DEP wire is "baked out" at high temperatures between
samples. The chromatograms below show the analysis of a 250 ng
Cholestane sample dissolved in methanol. This analysis was
repeated 5 times. The DEP coil was baked out at 900 mA for 15
seconds after each sample and then a blank clean methanol sam-
ple was analyzed. The blank injection produced a flat baseline with
no carryover from the previous samples.
The charts below show the MS data at 0.18 minutes for the 250
ng of Cholestane and the blank methanol sample. Note that the
scale on the blank methanol spectrum is 1000 times the scale of the
250 nanogram of Cholestane. No peaks were found in the blank
sample that could be attributed to the Cholestane. In this study, as
well as many others, it was confirmed that "memory effects" or
"cross contamination" problems do not occur with the AutoProbe
technique. It is recommended that the high temperature "bake out"
be used in all analysis. A blank sample between analysis is option-
al.
Sensitivity
Direct probe techniques are less sensitive than GC techniques
because the probe peaks in the total ion chromatograph are com-
paratively much wider and therefore less intense. However, by uti-
lizing the rapid temperature ramp capabilities of the AutoProbe,
sample sizes less than one nanogram have been detected and
identified.
Additional information is available on the web at:
www.sisweb.com/autoprobe
Background Check After Running Strong Samples
Typical Calibration Curve for an Analyte Using the AutoProbe
Background MS After Running 5 Consecutive Strong Samples
Voltages
AutoProbe Console Voltage:
110 VAC or 220 VAC
Edwards Vacuum Pump:
110 VAC or 220 VAC
Compressed Air: minimum 60 psi
Mass Spectrometer System Requirements
Thermo TRACE DSQ
TM
or Polaris Q
TM
MS
System with XcaliburTMSoftware
(Trace MS supported in our AP1000 AutoProbe)
Dimensions
Console without CTC PAL Autosampler:
17" wide x 42" Deep x 16" High
Console with CTC PAL Autosampler:
23" wide x 42" Deep x 37" High
Weight
Console Weight:
100 pounds
TRACE DSQTM, TRACE MS, Focus DSQ, DSQ II, Polaris QTM,
ThermoTM, XcaliburTM, and Open AccessTM are Trademarks of Thermo
Electron Corporation. - for mor information visit
www.thermofinnigan.com
AutoProbe System Specifications & Requirements
Part No.
Description
AutoProbe System
AutoProbe DCI Filament
Calibration Tip
AutoProbe Seal Set
Scientific Instrument Services, Inc.
TM
FAX: 908-806-6631
www.sisweb.com/catalog/08/A59
tip...
