Micromass GCT PM Protocol
Micromass GCT PM Protocol
Micromass GCT PM Protocol
Maintenance
Protocol
GCT
Serial Number
Date
Engineer
715000707_C
Performance Maintenance
This protocol is a guide to performing maintenance tasks on the mass specrometry
system. Packaged as part of the Performance Maintenance Kit, it is intended to ensure
optimum performance and an uninterrupted period of trouble-free operation of the Mass
Spectrometry System.
The performance maintenance tasks listed in this protocol do not expose electrical or
electronic components and can therefore be performed by either the customer or a fully
qualified Waters Field Service Engineer.
NOTE: This protocol contains complex procedures that require a high level of skill to
be completed successfully. Be sure to read through the whole document to determine
your competence before proceeding.
Schedule
Waters recommends that performance maintenance be conducted annually unless the
instrument documentation specifies otherwise. Systems under heavy use or using
aggressive solvents may need more frequent maintenance.
Task Summary
The PM protocol organizes performance maintenance tasks into three sections:
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Performance Maintenance Tasks
After completing each task, place a check mark in the Done column or record a value if
a result is required (or write NA if the procedure does not apply to the instrument). Add
comments as necessary.
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Initial Performance Checks
If the instrument fails to perform adequately during initial checks, it may need service work beyond the
scope of this Performance Maintenance Protocol. Such service work may incur additional parts and
labor charges.
Record values for each item in the table below; include comments where possible.
Open and close the isolation valve checking for an adequate response time and speed of operation.
Perform an MCP gain test to confirm that the detector system is serviceable.
With heptacosa (PFTBA) as the reference gas check that the largest peak in the spectrum is not likely to
saturate the detector when the MCP is set to 2800 V.
Acquire continuum data over the mass range 400 to 800 Da. Starting from 2100 V on the MCP
increase in 100 V increments at 1 minute intervals up to 3000 V.
Generate a BPI chromatogram and observe the relative size of the step at each voltage change. These
should reduce at each stage. If the intensity continues to rise in large steps the MCP may need
attention. Note that erroneous TDC settings, faulty attenuators and other factors can affect the result.
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Initial Performance Checks
Check the resolution at Full Width Half Maximum (FWHM) of the instrument in positive ion EI mode
measuring for the 614 and 502 peaks of Heptacosa (FC43).
Ensuring that the peaks are not saturated. Make hard copies of the data and tune page settings for
later reference.
502
EITHER:
Check the sensitivity in positive ion EI mode using a standard sample (e.g. signal to noise ratio for 1
pg hexachlorobenzene).
OR
When no GC is available check the mass accuracy off the solids probe using <50ng Methyl stearate.
Comparing the measured mass versus the accepted mass calculate the Root Mean Square (RMS) error
for all sample peaks above mass 70 and >10% of base peak intensity assuming no saturation.
Make hard copies of the data and tune page settings for later use.
Test Result
GC EI sensitivity Signal to Noise Ratio =
OR
Probe mass accuracy RMS error (mDa) =
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Maintenance Tasks
The following procedures are routinely performed as part of performance maintenance. Any additional
maintenance requirements identified in the previous section are beyond the scope of this document.
For more information on these procedures, refer to the instrument Owner’s Manual (in the preventive
maintenance section).
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Maintenance Tasks
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Maintenance Tasks
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Maintenance Tasks
Start 0V
Stop 2700 V
Step 1 minute
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Final Performance Checks
If the instrument fails to perform adequately during initial checks, it may need service work beyond the
scope of this Performance Maintenance Protocol. Such service work may incur additional parts and
labor charges.
Record values for each item in the table below; include comments where possible.
Open and close the isolation valve checking for an adequate response time and speed of operation.
Perform an MCP gain test to confirm that the detector system is serviceable.
With heptacosa (PFTBA) as the reference gas check that the largest peak in the spectrum is not likely to
saturate the detector when the MCP is set to 2800 V.
Acquire continuum data over the mass range 400 to 800 Da. Starting from 2100 V on the MCP
increase in 100 V increments at 1 minute intervals up to 3000 V.
Generate a BPI chromatogram and observe the relative size of the step at each voltage change. These
should reduce at each stage. If the intensity continues to rise in large steps the MCP may need
attention. Note that erroneous TDC settings, faulty attenuators and other factors can affect the result.
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Final Performance Checks
Check the resolution at Full Width Half Maximum (FWHM) of the instrument in positive ion EI mode
measuring for the 614 and 502 peaks of Heptacosa (FC43).
Ensuring that the peaks are not saturated. Make hard copies of the data and tune page settings for
later reference.
502
EITHER:
Check the sensitivity in positive ion EI mode using a standard sample (e.g. signal to noise ratio for 1
pg hexachlorobenzene).
OR
When no GC is available check the mass accuracy off the solids probe using <50ng Methyl stearate.
Comparing the measured mass versus the accepted mass calculate the Root Mean Square (RMS) error
for all sample peaks above mass 70 and >10% of base peak intensity assuming no saturation.
Make hard copies of the data and tune page settings for later use.
Test Result
GC EI sensitivity Signal to Noise Ratio =
OR
Probe mass accuracy RMS error (mDa) =
FI source
CI inner source
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PM Confirmation
Waters Corporation
34 Maple Street
Milford, MA 01757- U.S.A.
www.waters.com
Waters, Micromass, Connections and Waters Quality Parts are registered trademarks of Waters Corporation. All other
trademarks are property of their respective onwers.
©2005 Waters Corporation. Printed in the U.S.A. May 2005 – 715000707, Rev. C
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