Jasco PU-1580 User manual

P/N 0302-0390B
MODEL PU-1580
INTELLIGENT HPLC PUMP
MAINTENANCE MANUAL

i
Safety Considerations
To ensure operation safety, this instrument must be operated correctly and
maintained regularly according to schedule. Carefully read to fully understand all
safety precautions in this manual before operating the instrument. This manual
denotes precautions against actions that can result in hazardous situations or
equipment damage by using the signal words WARNING, CAUTION, and Note.
(1) Safety symbols
Instruction manual symbol. If the product is marked with this symbol,
refer to the instrument manuals to protect the instrument against
damage.
WARNING A WARNING indicates an potentially hazardous situation which, if not
avoided, could result in death or serious injury
.
CAUTION A CAUTION indicates a potentially hazardous situation which, if not
avoided, may result in minor or moderate injury. It may also be used
to alert against unsafe practices.
Do not proceed beyond a WARNING or CAUTION notice until you
understand the hazardous conditions and have taken the appropriate
steps.
Note A Note provides additional information to aid the operator in obtaining
optimal instrument performance.
Pressurized, hazardous solvents are used in high-performance liquid
chromatography. Always follow the proper laboratory procedures to ensure operator
safety. Always wear goggles, gloves and protective clothing when operating the
instrument, especially when injecting sample and opening valves.

ii
(2) Warning Labels
Warning labels are attached at several locations on this instrument. Do not remove,
deface or damage the warning labels. If a warning label peels off the instrument or
becomes illegible, contact your local JASCO distributor (See list on the back cover of
this manual) for a replacement label. Be sure to indicate the part number (P/N) on
the label.
(1) Fuse Warning Label (P/N: 0822-0120A)
Fuse ratings are indicated in the maintenance
manual.
(2) Electric Shock Warning Label (P/N: 0822-0125A)
Electric shock may occur if the instrument is not
properly grounded.
Since water pipes are often constructed of non-
metallic materials (e.g., polyvinyl chloride), do not
use these pipes for grounding purposes.
For safety reasons, do not use gas pipes for
grounding purposes.
FUSE
PUSH
FUSE
PUSH
T1.6A
T2.5A
100‑120V
220‑240V
FUSE
1
2
3
4
5
6
7
PRESS.ZERO
ADJ.
EVENT
VALVE
GRAD.
LOWPRESS.
8
ACINPUT
GND
FUSE
RS‑232C
R
R
(2) Electrical shock
warning label
(1) Fuse warning label
ONLY WITH FUSE OF THE SPECIFIED
AGAINST RISK OF FIRE, REPLACE
FOR CONTINUED PROTECTION
TYPE AND CURRENT RATINGS.
WARNING
Figure 1 Rear View of the UV-1580
ONLY WITH FUSE OF THE SPECIFIED
AGAINST RISK OF FIRE, REPLACE
FOR CONTINUED PROTECTION
TYPE AND CURRENT RATINGS.
WARNING
WARNING
MAINS PLUG GROUND PIN
OR GROUND TERMINAL
MUST BE CONNECTED
TO GROUND.

iii
Preface
This instruction manual serves as your guidebook for using this instrument. It is
intended to instruct first-time users on how to properly use the instrument, and to
serve as a reference for experienced users.
Before using the instrument, please read this instruction manual carefully, and make
sure that the contents are fully understood. This manual should be easily accessible to
the operator at all times during instrument operation. When not using the instrument,
keep this manual stored in a safe place. Should this instruction manual be lost, order a
replacement from your local JASCO distributor.
The manuals for this instrument consist of an operations manual and a maintenance
manual. This is the operations manual.

iv
Installation Conditions
To ensure safe operation, the following recommendations should be observed:
(1) Do not operate the instrument under voltage fluctuations exceeding 10%
of the recommended line voltage. Large fluctuations may cause the
instrument to fail.
(2) Use a three-pronged electrical outlet with a ground. When only a two-
pronged socket is available, use an adapter and be sure to connect the
ground wire of the adapter.
(3) Operate the instrument under a temperature range of 10 ∼30°C.
(4) Operate the instrument under a humidity range of 35 ∼85% (RH). If
ambient humidity exceeds 85% (RH), water vapor may deteriorate optical
components. If possible, install the instrument in a location having a
humidity of 60% or lower.
(5) Operate the instrument under an atmospheric pressure of 750 ∼1060 hPa.
(6) Avoid strong magnetic fields and sources of high-frequency waves. The
instrument may not function properly when near strong magnetic fields or
high-frequency wave sources.
(7) Avoid vibrations caused by vacuum pumps, electric motors, processing
equipment and machine tools.
(8) Avoid dust and corrosive gas. Do not install the instrument in a location
where it may be exposed to dust, especially in locations exposed to
outside air or ventilation outlets that discharge dust particles.
(9) Do not install the instrument in a location where it may be exposed to
direct sunlight.
(10) Do not install the instrument in a location where it may be directly exposed
to the air current from an air conditioner or heater, as such a location may
inhibit stable measurement.
Note: The above conditions do not ensure optimal performance of this instrument.

v
Maintenance
Consult your local JASCO distributor, listed at the back of this manual, regarding
maintenance. In addition, contact your local JASCO distributor representative when
transporting the instrument.
Replacement parts can be ordered according to part number from local JASCO
distributor. When the part number is not known, inform parts name,instrucment
model name and it’s serial number.
Notices
(1) Jasco shall not be held liable, either directly or indirectly, for any consequential
damage incurred as a result of the use of this product.
(2) Software prohibitions:
yCopying of software or related materials for purposes other than backup is
prohibited.
yTransfer or authorization of the use of Jasco software to or by a third party
is prohibited.
yDisclosure of confidential information related to Jasco software is prohibited.
yChanges or revisions to Jasco software are prohibited.
yUse of Jasco software on multiple workstations or terminals, through a
network or through any other means, is strictly prohibited. (This does not
apply to entities with the network license contract)
(3) The content of this manual is subject to change without notice in accordance
with product improvements.
(4) Unauthorized copying of this manual is prohibited.
(5) This manual shall not be used to guarantee or copyright industrial rights or other
rights.
(6) Company and product names listed herein are trademarks or registered
trademarks of various companies.

vi
Warranty
This product is warranted for a period of one year from the date of delivery. If any
defects should occur in the product during this period of warranty, JASCO will repair
or replace the defective part(s) or product free of charge.
This warranty does not apply to defects as a result of the following:
(1) USE FOLLOWING IMPROPER OR INADEQUATE INSTALLATION.
(2) IMPROPER OPERATION.
(3) MOVEMENT, MODIFICATION, OR REPAIR BY PERSONS OTHER THAN
AUTHORIZED JASCO PERSONNEL.
(4) USE OF PARTS OTHER THAN THOSE THAT ARE AUTHORIZED BY
JASCO.
(5) INORDINATELY RAPID DETERIORATION DUE TO THE USE OF
CORROSIVE SOLVENTS OR SAMPLES.
(6) NATURAL DISASTERS SUCH AS FIRES, WATER DAMAGE, OR
EARTHQUAKES.
In addition, this warranty does not cover:
CONSUMABLE PARTS OR PARTS THAT HAVE A SEPARATE WARRANTY OR A
WARRANTY PERIOD THAT IS DIFFERENT THAN THAT SPECIFIED ABOVE.
The warranty period for all parts and repairs supplied under this warranty expires
with the warranty period of the original product.
Jasco Corporation, 1998

vii
Table of Contents
Page
Safety Considerations .......................................................................... i
Preface................................................................................................. iii
Installation Conditions ........................................................................iv
Maintenance ..........................................................................................v
Warranty ...............................................................................................vi
Table of Contents................................................................................vii
1 Error Messages...............................................................................1
1.1 Errors during the self-diagnostic test when power is turned on............... 1
1.1.1 ROM, RAM, and DC power errors ............................................................ 1
1.1.2 Back-up errors .......................................................................................... 1
1.1.3 Pump sensor errors .................................................................................. 2
1.2 Errors during operation................................................................................. 2
1.2.1 Errors due to exceedingly high pressure .................................................. 3
1.2.2 Errors due to exceedingly low pressure.................................................... 3
1.2.3 External device errors............................................................................... 3
2 Troubleshooting..............................................................................4
2.1 Abnormal operating pressure....................................................................... 4
2.1.1 TROUBLE OVER PRESS errors .............................................................. 4
2.1.2 TROUBLE UNDER PRESS errors............................................................ 4
2.1.3 Large variations in operating pressure...................................................... 5
2.2 Baseline problems......................................................................................... 7
2.2.1 High baseline noise .................................................................................. 8
2.2.2 Spike-shaped baseline noise.................................................................... 8
2.2.3 Large baseline drift ................................................................................... 9
2.2.4 Periodic drift.............................................................................................. 9
2.2.5 Appearance of ghost peaks.................................................................... 10
2.3 Chromatogram problems ............................................................................ 10
2.3.1 Lengthening retention time ..................................................................... 10
2.3.2 Shortening retention time........................................................................ 10
2.3.3 Poor reproducibility for retention time ..................................................... 11
2.3.4 Poor reproducibility for peak areas or peak heights
(reproducibility for retention times is good)............................................. 11
2.3.5 Peak waveform problems (peak broadening, peak splitting) .................. 11
2.4 Pump section leaks ..................................................................................... 11
2.4.1 Plunger seal leaks .................................................................................. 12
2.4.2 Check valve assembly leaks................................................................... 13
2.4.3 Purge valve leaks ................................................................................... 14
2.4.4 Outlet port (line filter) leaks..................................................................... 15
2.4.5 Bottom panel drain port leaks................................................................. 16

viii
2.4.6 Inlet tube fitting leaks.............................................................................. 16
3 Pump Inspection and Calibration ................................................17
3.1 Pressure tests (pressure ramp and holding tests) ................................... 17
3.1.1 Preparation ............................................................................................. 17
3.1.2 Pressure Test 1 (pressure ramp test) ..................................................... 17
3.1.3 Pressure Test 2 (pressure holding test).................................................. 18
3.2 Adjustment of Zero Pressure...................................................................... 18
3.2.1 Conditions under which adjustment is required ...................................... 18
3.2.2 Adjustment using the PRESS ZERO ADJ trimmer ................................. 18
3.3 Flow rate calibration.................................................................................... 19
3.3.1 Conditions under which the flow rate must be adjusted ......................... 19
3.3.2 Input method for the flow rate calibration value...................................... 20
3.3.3 Flow rate calibration: Step 1 (without back pressure)............................ 20
3.3.4 Flow rate calibration: Step 2 (with back pressure) ................................. 21
4 Maintenance ..................................................................................23
4.1 Air bubble removal ...................................................................................... 23
4.2 Pump solvent replacement ......................................................................... 24
4.2.1 Solvent replacement preparations.......................................................... 24
4.2.2 Replacing the solvent with water ............................................................ 25
4.2.3 Replacing the water with methanol......................................................... 26
4.2.4 Notes on solvent replacement ................................................................ 26
4.3 Cleaning using an acid or alkaline solution ............................................. 27
4.3.1 Conditions under which cleaning is required .......................................... 27
4.3.2 Acid and alkaline solution concentrations............................................... 27
4.3.3 Cleaning procedure ................................................................................ 28
5 Part Replacement and Operations Check ...................................30
5.1 Plunger seal replacement ........................................................................... 30
5.1.1 Plunger seal replacement preparations .................................................. 30
5.1.2 Plunger seal removal .............................................................................. 31
5.1.3 Plunger seal installation.......................................................................... 35
5.1.4 Pump head, solvent selection valve, and purge valve attachment ......... 36
5.1.5 Post-replacement verification ................................................................. 37
5.2 Line filter replacement................................................................................. 37
5.2.1 Check for line filter clogs......................................................................... 37
5.2.2 Line filter replacement procedure ........................................................... 38
5.2.3 Post-replacement verification ................................................................. 39
5.3 Inlet filter replacement................................................................................. 39
5.3.1 How to check for inlet filter clogs ............................................................ 39
5.3.2 Inlet filter replacement procedure ........................................................... 39
5.4 Pump head check valve assembly replacement ....................................... 40
5.4.1 Preparations for check valve assembly replacement.............................. 40
5.4.2 Check valve assembly replacement procedure ...................................... 41
5.4.3 Post-replacement verification ................................................................. 43

ix
5.5 Replacement of the plunger washing mechanism diaphragm ................ 43
5.5.1 Preparations for diaphragm replacement ............................................... 43
5.5.2 Exposing the diaphragm......................................................................... 44
5.5.3 Diaphragm replacement ......................................................................... 45
5.5.4 Assembly of the head mount flange and other units............................... 45
5.5.5 Post-replacement verification ................................................................. 46
5.6 Purge valve needle and purge valve packing replacement...................... 46
5.6.1 Purge valve needle replacement ............................................................ 47
5.6.2 Purge valve packing replacement........................................................... 47
5.7 Plunger replacement ................................................................................... 48
5.7.1 Plunger replacement preparations.......................................................... 48
5.7.2 Exposing the plunger .............................................................................. 48
5.7.3 Plunger replacement............................................................................... 49
5.7.4 Assembly of head mount flange and other parts .................................... 51
5.7.5 Post-replacement verification ................................................................. 51
5.8 Solvent selection valve disk replacement ................................................. 51
5.9 List of consumable parts ............................................................................ 52

1
1 Error Messages
1.1 Errors during the self-diagnostic test when power is turned on
The PU-1580 automatically checks the following items when the power is turned on:
yROM (Memory)
yRAM (Memory)
yC-MOS RAM (Memory backed up by battery)
yDC power (Direct current power supply)
yPressure sensor
When there is an abnormality in any of the above areas, an ERROR will be
displayed on the LCD and the self-diagnostic test will be terminated.
1.1.1 ROM, RAM, and DC power errors
When ROM, RAM, DC POWER ERROR appears on the display, turn the power off
and then on again. If the error reoccurs, contact your local JASCO distributor.
1.1.2 Back-up errors
When the contents of the C-MOS RAM (Memory backed up by battery) have been
erased, BACK UP ERROR will appear on the display. When this happens, various
parameter settings will be erased and the default settings will be restored. If a BACK
UP ERROR occurs, the procedures listed below should be followed.
(1) While holding down the [SHIFT] key, press the [▼] key to continue the self-
diagnostic test.
(2) When the self-diagnostic test has been completed and the monitor screen
appears, refer to Section 3.3 to enter the flow rate calibration setting. This
should rectify the error, and the instrument should operate normally until the
power is turned off again.
Note: When using the pump in gradient mode or when the instrument is being
controlled by a system controller, the pump number ([SHIFT][4]), gradient
mode ([SHIFT][5]), program number ([SHIFT][PRGM]), and other settings
must be checked (Refer to the operations manual for details).
(3) If the error reoccurs the next time the power is turned on, the battery should
be replaced. Contact your local JASCO distributor for information on this
procedure.

2
1.1.3 Pump sensor errors
When the pump sensor signal exceeds the normal range (±1.0 MPa), P. SENSOR
ERROR will appear on the display.
Possible causes:
(1) Pump pressure is too high (1.0 MPa or higher).
This may occur for example when fluid is being pumped by a pump in the
high-pressure gradient system.
(2) Time variation in the pressure sensor.
(3) Malfunction in the pressure sensor or pressure sensor signal circuit.
What to do:
After opening the purge valve, turn the power off and then again. If the error
does not reoccur, the error was probably a result of the pump power being
turned on while the pump was pressurized. If the error reoccurs, time variation
in the pressure sensor or a malfunction in a sensor or signal circuit is the most
likely cause.
If an error arises due to time variation in the pressure sensor, zero the sensor
using the zero adjustment trimmer, then turn the power on again (See Section
3.2). If the problem continues, a malfunction has occurred in the pressure
sensor or pressure sensor signal circuit. If this happens, contact your local
JASCO distributor.
1.2 Errors during operation
Table 1 lists the problems that can be detected by the PU-1580 during operation.
When a problem is detected, a message will appear on the LCD. Press [CLEAR] to
return to the monitor screen.
Table 1.1 Error Messages During Operation
Error Message Meaning
TROUBLE OVER PRESS!!
TROUBLE UNDER PRESS!!
TROUBLE EXT. STOP IN!!
Operating pressure is too high
Operating pressure is too low
Pump has stopped due to an error
(stop) signal from an external
device
Note: When the setting time of the pump-off timer has elapsed, the PUMP STOP!!
TIMER OFF message will appear and solvent delivery will be terminated.

3
1.2.1 Errors due to exceedingly high pressure
If the operating pressure exceeds the maximum pressure (P.MAX) setting, a
TROUBLE OVER PRESS error message will appear on the display. If the operating
pressure is within an appropriate range, increase the maximum pressure (P.MAX)
setting. If the operating pressure is higher than the normal range, See Section 2.1.1
for information regarding how to deal with TROUBLE OVER PRESS errors.
1.2.2 Errors due to exceedingly low pressure
If the operating pressure drops below the minimum pressure (P.MIN) setting, a
TROUBLE UNDER PRESS error message will appear on the display. If the
operating pressure is within an appropriate range, decrease the minimum pressure
(P.MIN) setting. If the operating pressure is lower than the normal range, See
Section 2.1.2 for information regarding how to deal with TROUBLE UNDER PRESS
errors.
Note: The TROUBLE UNDER PRESS message will appear after the operating
pressure has remained below the minimum pressure setting for a period of
two minutes. Momentary pressure drops caused by bubbles drawn into the
pump are ignored.
1.2.3 External device errors
If an error occurs in an external device, a TROUBLE EXT. STOP IN error message
will appear on the display. If this happens, the external device in which the error has
occurred, i.e., the external device that output the stop signal, to normal operating
status.

4
2 Troubleshooting
2.1 Abnormal operating pressure
The PU-1580 continually monitors the operating pressure. Such monitoring is helpful
in detecting not only pump problems, but also problems such as clogged line filters.
Jasco recommends that the operating pressure and the pressure variation under
normal operating conditions be monitored closely.
This chapter describes likely causes for problems that might occur while using the
PU-1580. Refer to Fig. 2.1 for a list of part names used in this chapter. The
descriptions presented in this chapter are primarily concerned with pump problems
and how to deal with these problems.
2.1.1 TROUBLE OVER PRESS errors
Table 2.1 Dealing with TROUBLE OVER PRESS errors
Cause Confirmation Method What to Do
Downstream side of pump is
clogged
For example, a clog
occurring in the manual
injector, autosampler,
column filter, tubing, fittings,
or other sections.
Remove and examine devices
and/or part(s) that may be
clogged in the flow route
Refer to the
appropriate
manual
Line filter is clogged Operate the pump without
anything connected to the outlet
port. If the pressure is 2.0 MPa
or higher when pumping at 10
ml/min, the line filter is clogged
Replace the
line filter
(See Section
5.2)
Internal damper or internal
tubing(S) is clogged
Remove the outlet port line filter
and pump the solvent. If the
pressure is 2.0 MPa or higher
when pumping at 10 ml/min, the
internal damper or an internal
tubing is clogged.
This problem
requires service
by trained
JASCO service
personnel.
Contact your
local JASCO
distributor.
2.1.2 TROUBLE UNDER PRESS errors
Exceedingly low pressure may occur for one of two reasons. The first is that the
pump is not able to deliver solvent at the specified flow rate. The second is the
presence of a leak (such as a leak downstream from the pump) causing the actual
flow rate to be lower than specified, even though the solvent delivery capacity is
nominal. Table 2.2 lists potential causes, confirmation methods, and methods for
solving problems that may arise due to exceedingly low pressure.

5
Table 2.2 Dealing with TROUBLE UNDER PRESS errors
Cause Confirmation
Method
What to Do
Pump head contains air
bubbles
Open the purge valve and
remove the air bubbles (See
Section 4.1)
Inlet filter is clogged (use of
buffer solutions often leads
to clogging)
Check for
clogging
(See Section
5.3)
Replace the inlet filter
Plunger seal is leaking Tighten the pump head
securing screws (See Section
2.4.1)
If the leaking continues,
replace the plunger seal (See
Section 5.1)
Inlet tube fitting is leaking Tighten the fitting
(See Section 2.4.6)
Leak at downstream side of
pump (manual injector,
autosampler, column, fitting,
etc.)
Refer to the appropriate
manual
Pump head deterioration Perform
pressure tests
(See Section
3.1)
Clean the pump head
thoroughly using an acid or
alkaline solution
(See Section 4.3)
2.1.3 Large variations in operating pressure
Table 2.3 lists potential causes, confirmation methods, and methods for solving
problems that may arise due to large variations in operating pressure.

6
Table 2.3 Dealing with Large Pressure Variations
Cause Confirmation
Method
What to Do
Pump head contains
air bubbles
Open the purge valve and remove
the air bubbles (See Section 4.1)
Inlet filter is clogged
(use of buffer
solutions often leads
to clogging)
See Section 5.3.1 Replace the inlet filter if clogged
Insufficient
degassing of the
solvent
Degas the solvent
Inlet tube fitting is
leaking
Tighten the fitting
(See Section 2.4.6)
Plunger seal is
leaking
Tighten the pump head securing
screws
(See Section 2.4.1)
If leaking continues, replace the
plunger seal (See Section 5.1)
Pump head
deterioration
Perform pressure
tests
(See Section 3.1)
Clean the pump head thoroughly
using an acid or alkaline solution
(See Section 4.3)
Abnormal plunger
movement
Sound of metal
contacting metal
can be heard
Loosen the pump head securing
screws slightly

7
Inlet tube
Check valve assembly (OUT)
Head mount flange
Drain pipe
Inlet filter Pump heads
Left side: Delivery head
Right side: Modifier head
Solvent selection valve knob
(or "knob") Purge valve knob Outlet port (line filter inside)
Check valve assembly (IN)
Pump head
Outlet port
Drain port
Bottom view
Head mount flange
Figure 2.1 Pump Parts and Part Names
2.2 Baseline problems
This section describes problems that may occur when the detector is a UV detector.

8
2.2.1 High baseline noise
Table 2.4 lists potential causes, confirmation methods, and methods for solving
problems that may arise due to high baseline noise.
Table 2.4 Dealing with High Baseline Noise
Cause Confirmation
Method
What to Do
Variations in pump pressure Stop solvent delivery.
If the noise
disappears, the
cause lies in the
pump. If the noise
remains, the cause
lies in the UV
detector.
See Section 2.1.3.
(Particularly when the
pressure monitor shows
large variations in
pressure.)
Mixing noise (when running a
gradient program or using a
post-column derivatization
system)
See above Add an extra mixer or
damper to the pump
Detector cell problems
Bubbles
Contamination
Leakage
Refer to the
maintenance manual of
the UV detector
Decrease in the light intensity
of the detector
Light source deterioration
Mirror deterioration
Refer to the
maintenance manual of
the UV detector
2.2.2 Spike-shaped baseline noise
Table 2.5 lists potential causes, confirmation methods, and methods for dealing with
spike-shaped baseline noise.
Table 2.5 Dealing with Spike-Shaped Baseline Noise
Cause Confirmation Method What to Do
Bubbles in the cell (In this
case, spike-shaped noise
occurs only toward
increasing absorption)
Stop solvent delivery. If the
noise stops, there are
probably air bubbles in the
cell
Refer to the
maintenance
manual for the UV
detector
Electrical noise Ground the
instrument

9
2.2.3 Large baseline drift
Table 2.6 lists potential causes, confirmation methods, and methods for dealing with
large baseline drift.
Table 2.6 Dealing with Large Baseline Drift
Cause Confirmation Method What to Do
Insufficient solvent
replacement
Does the drift level decrease with
time?
Wait (increase the
flow rate if
necessary)
Insufficient column
equilibration
See above See above
Time variation of
eluent (composition,
dissolved gas level,
etc.)
Use an eluent that is
better suited to the
conditions
Detector instability
(cell bubbles,
contamination,
leakage, etc.)
Refer to the
maintenance manual
of the UV detector
Eluent contamination Lengthen the detector
wavelength. If the drift
decreases, there is a problem
with the eluent
Use a higher grade
eluent
Contamination of
pump or equipment
upstream from the
pump
Lengthen the detector
wavelength. If the drift becomes
smaller, there is a problem with
equipment contamination
Clean the
contaminated device
using an acid or an
alkaline solution
(See Section 4.3)
Contamination
downstream from the
pump (manual
injector, autosampler,
column, tubing,
fittings)
Remove the device or part that
appears to be contaminated and
check the drift
Clean or replace the
contaminated device
or part
2.2.4 Periodic drift
Table 2.7 lists a potential cause, a confirmation method, and a method for dealing
with periodic drift.

10
Table 2.7 Dealing with Periodic Baseline Drift
Cause Confirmation Method What to Do
Variations in ambient
temperature
Is a breeze from the air
conditioner striking a
column or detector?
Protect the column
using thermal
insulation or a
windbreak
2.2.5 Appearance of ghost peaks
Table 2.8 lists potential causes, confirmation methods, and methods for dealing with
ghost peaks.
Table 2.8 Dealing with Ghost Peaks
Cause Confirmation
Method
What to Do
Contamination of pump or
equipment upstream from the
pump
Clean using an acid or
an alkaline solution
(See Section 4.3)
Eluent contamination Use a higher grade
eluent
Contamination in sample
injection section (manual
injector or autosampler)
Watch the ghost
peaks while injecting
eluent in the sample
injection section
Clean any equipment
that has been
determined to be
contaminated
2.3 Chromatogram problems
2.3.1 Lengthening retention time
Table 2.9 lists potential causes, confirmation methods, and methods for dealing with
lengthening retention times.
Table 2.9 Dealing with Lengthening Retention Times
Cause Confirmation Method What to Do
Decrease in actual flow
rate
See Section 2.1.2
Insufficient column
equilibration
Increase the column re-
equilibration time
Variation in ambient
temperature
Is a breeze from the air
conditioner striking the
column?
Protect the column
using thermal insulation
Variation in eluent
composition
Prepare the eluent
again
2.3.2 Shortening retention time