Agilent Technologies 7200 Troubleshooting And Maintenance Manual
Agilent 7200
Accurate-Mass/Q-TOF
GC/MS System
Troubleshooting and
Maintenance Manual
Agilent Technologies
Notices
CAUTION
WARNING
© Agilent Technologies, Inc. 2012, 2014
No p art o f this manu al may be re produce d in
any form or by any means (including electronic storage and retrieval or translation
into a foreign language) without prior agreement and written consent from Agilent
Technologies, Inc. as governed by United
States and international copyright laws.
Manual Part Number
G3850-90009
Edition
First Edition, August 2014
Printed in USA
Agilent Technologies, Inc.
5301 Stevens Creek Boulevard
Santa Clara, CA 95051
Warranty
The material contained in this document is provided “as is,” and is subject to being changed, without notice,
in future editions. Further, to the maximum extent permitted by applicable
law, Agilent disclaims all warranties,
either express or implied, with regard
to this manual and any information
contained herein, including but not
limited to the implied warranties of
merchantability and fitness for a particular purpose. Agilent shall not be
liable for errors or for incidental or
consequential damages in connection with the furnishing, use, or performance of this document or of any
information contained herein. Should
Agilent and the user have a separate
written agreement with warranty
terms covering the material in this
document that conflict with these
terms, the warranty terms in the separate agreement shall control.
Safety Notices
A CAUTION notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly
performed or adhered to, could
result in damage to the product or
loss of important data. Do not
proceed beyond a CAUTION notice
until the indicated conditions are
fully understood and met.
A WARNING notice denotes a
hazard. It calls attention to an
operating procedure, practice, or
the like that, if not correctly
performed or adhered to, could
result in personal injury or death.
Do not proceed beyond a
WARNING notice until the
indicated conditions are fully
understood and met.
2 Troubleshooting and Maintenance Manual
Contents
1 Introduction
Abbreviations Used 8
The 7200 Accurate-Mass Quadrupole Time-of-Flight GC/MS
System 10
7200 Accurate-Mass Q-TOF GC/MS Description 12
Side Panel AC Power Connectors 13
Back Panel Connectors 14
Interfacing Start Events to External Devices 15
Remote control processor 15
Remote start signals 15
System ready 15
Start run input 16
Important Safety Warnings 17
Safety and Regulatory Certifications 20
Intended Use 23
Cleaning/Recycling the Product 23
Moving or Storing the MS 23
2 General Troubleshooting
Troubleshooting Tips and Tricks 26
General Symptoms 27
Chromatographic Symptoms 29
Mass Spectra General Symptoms 34
Pressure Symptoms 36
Temperature Symptoms 38
Troubleshooting and Maintenance Manual 3
Common Types of Errors 40
Air Leaks 45
Contamination 46
3 CI Troubleshooting
Common CI-Specific Problems 50
Troubleshooting Tips and Tricks 51
Air Leaks 52
Pressure-Related Symptoms 55
Signal-Related Symptoms 58
Tuning-Related Symptoms 64
The CI ion source is dirty 65
Air leak 65
4 General Maintenance
Before Starting 68
Scheduled maintenance 68
Tools, spare parts, and supplies 69
High voltage precautions 69
Dangerous temperatures 69
Chemical residue 70
Electrostatic discharge 71
To Refill the EI Calibration Vial 72
Materials needed 72
Refill 72
To Refill the IRM Vial 74
Materials needed 74
Procedure 74
To Connect the GC Nitrogen Gas Source to the Collision Cell 76
4 Troubleshooting and Maintenance Manual
5 CI Maintenance
Materials needed 76
Procedure 76
To Replace the Seals in the RIS Probe 77
Materials needed 77
Procedure 77
To Separate the GC from the MS 79
Materials needed 79
Procedure 79
To Position the GC Next to the MS 82
Procedure 82
To Move or Store the MS 83
Materials needed 83
Procedure 83
To Access the Left Side Lifting Handle 86
Materials needed 86
Procedure 87
To Minimize Foreline Pump Damage from Ammonia 90
To Replace the Methane/Isobutane Gas Purifier 91
To Clean the Reagent Gas Supply Lines 92
To Refill the CI Calibration Vial 93
Materials needed 93
Refill 93
6Vacuum System
Overview 96
Maintaining the Vacuum System 97
Periodic maintenance 97
Other procedures 97
Troubleshooting and Maintenance Manual 5
Vacuum System Components 97
Common Vacuum System Problems 98
Foreline Pump 99
To check the oil mist filter 99
To check the foreline pump fluid level 100
To add foreline pump fluid 100
To replace the foreline pump fluid 101
Side Plate 104
Vacuum Seals 104
Calibration Valves 105
EI Calibration Valve 105
CI Calibration Valve 106
IRM Calibration Valves 107
7Replacement Parts
To Order Parts 110
Electronics 111
Vacuum System 116
Analyzer 121
RIS Manifold 130
GC/MS Interface 132
Consumables and Maintenance Supplies 133
6 Troubleshooting and Maintenance Manual
Agilent 7200 Accurate-Mass Q-TOF GC/MS System
Troubleshooting and Maintenance Manual
1
Introduction
Abbreviations Used 8
The 7200 Accurate-Mass Quadrupole Time-of-Flight GC/MS System 10
7200 Accurate-Mass Q-TOF GC/MS Description 12
Side Panel AC Power Connectors 13
Interfacing Start Events to External Devices 15
Important Safety Warnings 17
Safety and Regulatory Certifications 20
Intended Use 23
Cleaning/Recycling the Product 23
Moving or Storing the MS 23
This section provides general information about the 7200 Accurate-Mass
Quadrupole Time-of-Flight (Q-TOF) GC/MS System, including a hardware
description and general safety warnings.
Agilent Technologies
7
1 Introduction
Abbreviations Used
The abbreviations in Table 1 are used in discussing this product. They are
collected here for convenience.
Tab l e 1 Abbreviations
Abbreviation Definition
AC Alternating current
ALS Automatic liquid sampler
BFB Bromofluorobenzene (calibrant)
CC Collision cell
CI Chemical ionization
DC Direct current
DFTPP Decafluorotriphenylphosphine (calibrant)
DIP Direct insertion probe
EI Electron impact
EPC Electronic pneumatic control
eV Electron volt
GC Gas chromatograph
id Inside diameter
IRM Internal Reference Mass
LAN Local Area Network
m/z Mass to charge ratio
MFC Mass flow controller
MS Mass spectrometer
MS1 Front quadrupole
NCI Negative chemical ionization
OFN Octafluoronaphthalene (sample)
8 Troubleshooting and Maintenance Manual
Tab l e 1 Abbreviations (continued)
Abbreviation Definition
PCI Positive chemical ionization
PFDTD Perfluoro-5,8-dimethyl-3,6,9-trioxydodecane (calibrant)
PFET 2,4,6-tris (Pentafluoroethyl)-1,3,5-triazine
PFTBA Perfluorotributylamine (calibrant)
Q-TOF Quadrupole time-of-flight
Quad Quadrupole mass filter
RF Radio frequency
RFPA Radio frequency power amplifier
TOF Time-of-flight
Torr Unit of pressure, 1 mm Hg
Turbo Turbomolecular vacuum pump
Introduction 1
Troubleshooting and Maintenance Manual 9
1 Introduction
The 7200 Accurate-Mass Quadrupole Time-of-Flight GC/MS System
The 7200 Accurate-Mass Quadrupole Time-of-Flight (Q-TOF) GC/MS System is
a standalone capillary GC detector for use with the Agilent 7890 Series gas
chromatograph. The 7200 Q-TOF features:
• Three turbomolecular vacuum pumps
• Rotary vane foreline pump
• Independently MS-heated EI or CI ion source
• Removable ion source (RIS) probe with bayonet and cooling chamber, which
allows quick change from EI to CI source with minimal loss of vacuum in
the instrument
• Independently MS-heated hyperbolic quadrupole mass filter, which can be
heated to high temperatures, minimizing the contamination typical with
low temperature analyses
• Single hexapole collision cell
• Vacuum-insulated f light tube with dual-stage ion mirror
• Fast electronics, allowing fast sampling rates
• Analog to digital detector
• Independently GC-heated GC/MS interface with automatic retraction
during source removal
Physical description
The 7200 Q-TOF GC/MS is approximately 48 cm high, 71 cm wide, and 89 cm
deep. The flight tube extends 84 cm up over the top of the instrument. The RIS
probe handle, when attached, extends 48 cm from the front of the instrument.
The weight of the instrument is 152 kg for the turbo pump mainframe. The
attached foreline (roughing) pump weighs an additional 22.2 kg.
The basic components of the instrument are: the frame/cover assemblies, the
vacuum system, the GC/MS interface, the removable ion source, the f light tube
electronics, the collision cell, the detector, and the analyzer.
10 Troubleshooting and Maintenance Manual
Vacuum gauge
The 7200 Q-TOF GC/MS is equipped with four ion vacuum gauges:
• RIS vacuum chamber
• Vacuum manifold chamber
• TOF vacuum manifold chamber
• Turbomolecular vacuum pumps exhaust
The MassHunter Workstation can be used to read the pressure (high vacuum)
in the vacuum manifold, at the turbomolecular vacuum pump discharge, and
the flight tube.
Ionization modes
The G3851BA 7200 Accurate-Mass Q-TOF GC/MS comes standard with both an
EI and CI removable ion source (RIS).
A methane/isobutane gas purifier is provided and is required. It removes
oxygen, water, hydrocarbons, and sulfur compounds.
The MS CI system has been optimized to achieve the relatively high source
pressure required for CI while still maintaining high vacuum in the collision
cell, quadrupole, and TOF tube. Special seals along the flow path of the
reagent gas and very small openings in the ion source keep the source gases in
the ionization volume long enough for the appropriate reactions to occur.
Introduction 1
The interface has special plumbing for reagent gas. A retractable insulating
seal fits onto the tip of the interface and is used for both EI and CI.
Switching back and forth between CI and EI sources takes less than 30
minutes with the new removable ion source. The RIS allows the instrument to
remain close to pressure, and provides a cooling chamber with N2 purge for
rapid source cooling without venting the machine. This saves hours in cycle
time over the traditional unit.
Troubleshooting and Maintenance Manual 11
1 Introduction
7200 Series MS
MS power
switch
7890 GC
GC power switch
7200 Accurate-Mass Q-TOF GC/MS Description
Figure 1 is an overview of a typical 7200 Accurate-Mass Q-TOF GC/MS system.
Figure 1 7200 Q-TOF GC/MS System
12 Troubleshooting and Maintenance Manual
Side Panel AC Power Connectors
Introduction 1
Figure 2 Side panel power supply (left) and back panel connections (right)
Foreline pump power receptacle (top)
The foreline pump power cord receptacle located on the left side of the MS
provides AC power for the foreline pump. If the power switch is off, no power
is supplied to the foreline pump.
Main power cord receptacle (bottom)
The AC power cord located on the left side of the MS brings in all electrical
power for the MS. The power cord can be detached from the MS.
Troubleshooting and Maintenance Manual 13
1 Introduction
Back Panel Connectors
Figure 3 Side panel power supply (left) and back panel connections (right)
Remote start connector
The remote start connector is the external connector for the remote start
circuitry on the LAN/MS control card. It receives remote start signals from the
GC.
LAN (I/O) connector
The LAN cable from the data system is connected to the LAN communications
connector. It carries all data communication between the PC and the MS.
14 Troubleshooting and Maintenance Manual
Interfacing Start Events to External Devices
Start Ground
Ready
Remote control processor
The remote control processor on the LAN/MS control card synchronizes
start-run signals with GCs and other devices. The functions of the remote
control processor are extended to the remote start (Remote) connector
(Figure 4) on the back panel of the MS. The remote start cable connects the GC
and the MS. An optional cable can extend these events to another instrument.
Remote start signals
It is often necessary to communicate with external devices (for example, a
purge-and-trap) during a run. Typically, these communications are requests to
send a system-ready signal. They also include:
• Receive a start run signal from an external device
• Program the timing of events during a run
Introduction 1
Figure 4 Remote start connector
System ready
When interfacing to an external device, it is often desirable to send a
system-ready signal to the device. In the case of a multi-sample Tekmar
purge-and-trap, each sample is purged onto a trap where it waits for a ready
signal. On receipt of the ready signal, the desorption cycle begins. When a
specific temperature is reached, the purge-and-trap closes a contact to
indicate the run has started.
Troubleshooting and Maintenance Manual 15
1 Introduction
Start run input
The ready pin on the remote start connector on the GC is held low at all times
except when the GC, MS, and data system are all ready. On system ready, a
logic high of 5 VDC is present between that pin and any ground. This same
high can be detected between the ready and ground pins on the remote start
connector on the MS.
The best way to generate a start run signal is to use the remote start connector
on the GC. Since remote start cables are made for most common devices, this
is often the simplest way. A general-purpose remote start cable (Y-Remote
Start/Stop, NON APG p/n G1530-61200), is also available that terminates in
spade lugs. Care must be taken to ensure that the system is actually ready
before the start run signal is sent.
If necessary, the remote start connector on the back of the MS can be used to
send the start run signal. A contact closure between the start and ground pins
will start the run if the system is ready.
16 Troubleshooting and Maintenance Manual
Important Safety Warnings
WARNING
WARNING
There are several important safety notices to always keep in mind when using
the MS.
Many internal parts of the MS carry dangerous voltages
If the MS is connected to a power source, even if the power switch is off,
potentially dangerous voltages exist on:
• The wiring between the MS power cord and the AC power supply
• The AC power supply itself
• The wiring from the AC power supply to the power switch
With the power switch on, potentially dangerous voltages also exist on:
• All electronics boards in the instrument
• The internal wires and cables connected to these boards
• The wires for any heater (oven, detector, inlet, or valve box)
Introduction 1
Troubleshooting and Maintenance Manual 17
All these parts are shielded by covers. With the covers in place, it should be difficult
to accidentally make contact with dangerous voltages. Unless specifically
instructed to, never remove a cover unless the detector, inlet, and oven are turned
off.
If the power cord insulation is frayed or worn, the cord must be replaced. Contact
your Agilent service representative.
Electrostatic discharge is a threat to MS electronics
The printed circuit boards in the MS can be damaged by electrostatic
discharge. Do not touch any of the boards unless it is absolutely necessary. If
you must handle them, wear a grounded wrist strap and take other antistatic
precautions.
1 Introduction
WARNING
WARNING
WARNING
Precautions to take to prevent an explosion
The use of hydrogen gas is specifically prohibited with this product.
You MUST make sure the top thumbscrew on the front analyzer side plate and the
top thumbscrew on the rear analyzer side plate are both fastened finger-tight. Do not
overtighten the thumbscrews; this can cause air leaks.
You MUST leave the collision cell chamber top plate shipping brackets fastened. Do
not remove the shipping brackets from the top plate for normal operation; they
secure the top plate in the event of an explosion.
Failure to secure your MS as described above greatly increases the chance of
personal injury in the event of an explosion.
18 Troubleshooting and Maintenance Manual
Many parts are dangerously hot
Many parts of the GC/MS operate at temperatures high enough to cause
serious burns. These parts include, but are not limited to the:
• Inlet
• Oven and its contents
• Val ve box
• Column nuts attaching the column to an inlet or detector
• Foreline pump
• GC/MS transfer line
Always cool these areas of the system to room temperature before working on
them. They will cool faster if you first set the temperature of the heated zone
to room temperature. Turn the zone off after it has reached the setpoint. If you
must perform maintenance on hot parts, use a wrench and wear gloves.
Whenever possible, cool the part of the instrument that you will be
maintaining before you begin working on it.
WARNING
Be careful when working behind the instrument. During cool-down cycles, the GC
WARNING
WARNING
emits hot exhaust that can cause burns.
The insulation around the inlets, detectors, valve box, and the insulation cups is
made of refractory ceramic fibers. To avoid inhaling fiber particles, we recommend
the following safety procedures: ventilate your work area; wear long sleeves,
gloves, safety glasses, and a disposable dust/mist respirator; dispose of insulation
in a sealed plastic bag in accordance with local regulations; wash your hands with
mild soap and cold water after handling the insulation.
The oil pan under the standard foreline pump can be a fire hazard
Oily rags, paper towels, and similar absorbents in the oil pan could ignite and
damage the pump and other parts of the MS.
Introduction 1
Combustible materials (or flammable/nonflammable wicking material) placed
under, over, or around the foreline (roughing) pump constitutes a fire hazard. Keep
the pan clean, but do not leave absorbent material such as paper towels in it.
Troubleshooting and Maintenance Manual 19
1 Introduction
Safety and Regulatory Certifications
The 7200 Q-TOF GC/MS conforms to the following safety standards:
• Canadian Standards Association (CSA): CAN/CSA-C22.2 No. 61010-1-04
• CSA/Nationally Recognized Test Laboratory (NRTL): UL 61010–1
• International Electrotechnical Commission (IEC): 61010–1
• EuroNorm (EN): 61010–1
The 7200 Q-TOF GC/MS conforms to the following regulations on
Electromagnetic Compatibility (EMC) and Radio Frequency Interference
(RFI):
• CISPR 11/EN 55011: Group 1, Class A
• IEC/EN 61326-1
• AUS/NZ
This ISM device complies with Canadian ICES-001. Cet appareil ISM est
conforme a la norme NMB—001 du Canada.
The 7200 Q-TOF GC/MS is designed and manufactured under a quality system
registered to ISO 9001.
Information
The Agilent Technologies 7200 Accurate-Mass Q-TOF GC/MS meets the
following IEC (International Electrotechnical Commission) classifications:
Equipment Class I, Laboratory Equipment, Installation Category II, and
Pollution Degree 2.
This unit has been designed and tested in accordance with recognized safety
standards and is designed for use indoors. If the instrument is used in a
manner not specified by the manufacturer, the protection provided by the
instrument may be impaired. Whenever the safety protection of the MS has
been compromised, disconnect the unit from all power sources and secure the
unit against unintended operation.
20 Troubleshooting and Maintenance Manual
Symbols
Introduction 1
Refer servicing to qualified service personnel. Substituting parts or
performing any unauthorized modification to the instrument may result in a
safety hazard.
Warnings in the manual or on the instrument must be observed during all
phases of operation, service, and repair of this instrument. Failure to comply
with these precautions violates safety standards of design and the intended
use of the instrument. Agilent Technologies assumes no liability for the
customer’s failure to comply with these requirements.
See accompanying instructions for more information.
Indicates a hot surface.
Indicates hazardous voltages.
Indicates earth (ground) terminal.
Indicates potential explosion hazard.
Indicates radioactivity hazard.
Indicates electrostatic discharge hazard.
Indicates that you must not discard this
electrical/electronic product in domestic household
waste.
Troubleshooting and Maintenance Manual 21
1 Introduction
Electromagnetic compatibility
This device complies with the requirements of CISPR 11. Operation is subject
to the following two conditions:
• This device may not cause harmful interference.
• This device must accept any interference received, including interference
that may cause undesired operation.
If this equipment does cause harmful interference to radio or television
reception, which can be determined by turning the equipment off and on, the
user is encouraged to try one or more of the following measures:
1 Relocate the radio or antenna.
2 Move the device away from the radio or television.
3 Plug the device into a different electrical outlet, so that the device and the
radio or television are on separate electrical circuits.
4 Make sure that all peripheral devices are also certified.
5 Make sure that appropriate cables are used to connect the device to
peripheral equipment.
6 Consult your equipment dealer, Agilent Technologies, or an experienced
technician for assistance.
Changes or modifications not expressly approved by Agilent Technologies
could void the user’s authority to operate the equipment.
Sound emission declaration
Sound pressure
Sound pressure Lp < 70 dB according to EN 27779:1991 and
EN ISO 3744:1995.
Schalldruckpegel
Schalldruckpegel LP < 70 dB nach EN 27779:1991 und EN ISO 3744:1995.
22 Troubleshooting and Maintenance Manual
Intended Use
Agilent products must only be used in the manner described in the Agilent
product user guides. Any other use may result in damage to the product or
personal injury. Agilent is not responsible for any damages caused, in whole or
in part, by improper use of the products, unauthorized alterations,
adjustments or modifications to the products, failure to comply with
procedures in Agilent product user guides, or use of the products in violation
of applicable laws, rules or regulations.
Cleaning/Recycling the Product
To clean the unit, disconnect the power and wipe down with a damp, lint-free
cloth. For recycling, contact your local Agilent sales office.
Moving or Storing the MS
Introduction 1
The best way to keep your MS functioning properly is to keep it pumped down
and hot, with carrier gas flow. If you plan to move or store your MS, a few
additional precautions are required. The MS must remain upright at all times;
this requires special caution when moving. The MS should not be left vented to
atmosphere for long periods. For more information, see “To Move or Store the
MS” on page 83.
Troubleshooting and Maintenance Manual 23
1 Introduction
24 Troubleshooting and Maintenance Manual
Agilent 7200 Accurate-Mass Q-TOF GC/MS System
Troubleshooting and Maintenance Manual
2
General Troubleshooting
Troubleshooting Tips and Tricks 26
General Symptoms 27
Chromatographic Symptoms 29
Mass Spectra General Symptoms 34
Pressure Symptoms 36
Temperature Symptoms 38
Common Types of Errors 40
Air Leaks 45
Contamination 46
This is a quick reference to symptoms and possible causes of the most
common problems experienced by users. For each symptom, one or more
possible causes are listed. In general, the causes listed first are the most likely
causes or the easiest to check and correct.
This chapter does not include corrective actions for the possible causes listed.
Some of the corrective actions required may be dangerous if performed
incorrectly. Do not attempt any corrective actions unless you are sure you
know the correct procedure and the dangers involved. See the other chapters
in this manual for more information.
If the material in this chapter and in the online help proves insufficient to help
you diagnose a problem, contact your Agilent Technologies service
representative.
Agilent Technologies
25
2 General Troubleshooting
Troubleshooting Tips and Tricks
Rule 1: “Look for what has been changed.”
Many problems are introduced accidentally by human actions. Every time any
system is disturbed, there is a chance of introducing a new problem.
• If the MS was just pumped down after maintenance, suspect air leaks or
incorrect assembly.
• If carrier gas or helium gas purifier was just changed, suspect leaks or
contaminated or incorrect gas.
• If the GC column was just replaced, suspect air leaks or a contaminated or
bleeding column.
Rule 2: “If complex isn’t working, go back to simple.”
A complex task is not only more difficult to perform but also more difficult to
troubleshoot. If you’re having trouble detecting your sample, verify that
autotune is successful.
Rule 3: “Divide and conquer.”
This technique is known as “half-split” troubleshooting. If you can isolate the
problem to only part of the system, it is much easier to locate.
To determine whether an air leak is in the GC or the MS, you can vent the MS,
remove the column, and install the blank interface ferrule. If the leak goes
away, it was in the GC.
26 Troubleshooting and Maintenance Manual
General Symptoms
This section describes symptoms you might observe when first turning on the
GC/MS system. All of these symptoms would prevent operation of the system.
GC does not turn on
Nothing happens when the GC is switched on. The GC fans do not turn on and
the keypad display does not light.
• Disconnected GC power cord
• No voltage or incorrect voltage at the electrical outlet
• Failed fuse in the GC
• GC power supply is not working correctly
MS does not turn on
Nothing happens when the MS is switched on. The foreline pump does not
start. The cooling fan for the high-vacuum pump does not turn on.
• Disconnected MS power cord
• No voltage or incorrect voltage at the electrical outlet
• Failed primary fuses - Not user replaceable
• MS electronics are not working correctly
General Troubleshooting 2
Foreline pump is not operating
The MS is receiving power (the fan is operating) but the foreline pump is not
operating.
• A large air leak (usually the analyzer door open) has caused pumpdown
failure. You must power cycle the MS to recover from this state.
• Disconnected foreline pump power cord
• Malfunctioning foreline pump
• Check power switch on foreline pump
Troubleshooting and Maintenance Manual 27
2 General Troubleshooting
MS turns on but then the foreline pump shuts off
The MS will shut down both the foreline pump and the turbo pumps if the
system fails to pump down correctly. This is usually because of a large air leak
or the side plate has not sealed correctly. This feature helps prevent the
foreline pump from sucking air through the system, which can damage the
analyzer and the turbo pumps.
You must power cycle the MS to recover from this state.
28 Troubleshooting and Maintenance Manual
Chromatographic Symptoms
These are symptoms you may observe in the chromatograms generated by data
acquisition. In general, these symptoms do not prevent you from operating
your GC/MS system. They indicate, however, that the data you are acquiring
may not be the best data obtainable. These symptoms can be caused by
instrument malfunctions but are more likely caused by incorrect
chromatographic technique.
Two of the symptoms, Low sensitivity and Poor repeatability also apply to
mass spectral data.
No peaks
If an analysis shows no chromatographic peaks, only a flat baseline or minor
noise, run the automated tune program. If the MS passes tune, the problem is
most likely related to the GC. If the MS does not pass tune, the problem is most
likely in the MS.
Passes tune
General Troubleshooting 2
• Incorrect sample concentration
• No analytes present
• Syringe missing from the ALS or not installed correctly
• Injection accidentally made in split mode instead of splitless mode
• Empty or almost empty sample vial
• Dirty GC inlet
• Leaking GC inlet*
• Loose column nut at the GC inlet*
* This could cause a fault condition in the GC that would prevent the GC
from operating.
Does not pass tune
• Calibration vial is empty
• Excessive foreline or analyzer chamber pressure
• Very d i r t y i o n s o ur c e
Troubleshooting and Maintenance Manual 29
2 General Troubleshooting
• Calibration valve is not working correctly
• Bad signal cable connection
• Filament has failed or is not connected correctly
• Bad ion source wiring connection
• Bad detector wiring connection
• Failed MS detector
Peaks are tailing
• Active sites in the sample path
• Injection is too large
• Incorrect GC inlet temperature
• Insufficient column flow
• GC/MS interface temperature is too low
• Ion source temperature is too low
Peaks are fronting
• Column film thickness mismatched with analyte concentration (column
overload)
• Initial oven temperature is too low
• Active sites in the sample path
• Injection is too large
• GC inlet pressure too high
• Insufficient column flow
Peaks have flat tops
• Insufficient solvent delay
• Incorrect scale on the display
• Injection is too large
30 Troubleshooting and Maintenance Manual
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