Agilent 6890 User manual

Agilent 6890

Gas Chromatograph

Maintaining Your GC

Agilent Technologies

Notices

© Agilent Technologies, Inc. 2007

No part of this manual may be reproduced 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

G1530-90010

Edition

First edition, March 2007

Printed in USA

Agilent Technologies, Inc.

2850 Centerville Road

Wilmington, DE 19808-1610 USA

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

CAUTION

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.

WARNING

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.

Contents

1 About Maintaining the GC

Overview of Maintenance 10

Tools and Materials Required for Maintenance 12

Safety Information 14

Preparing the GC for Maintenance 15

2 Maintaining Capillary Columns

Consumables and Parts for Columns		18
To Install a Capillary Column Hanger		19
To Condition a Capillary Column	20
To Cut a Loop from a Column	23
To Reverse a Column and Bakeout Contaminants 24
To Attach a Capillary Column Using SilTite Metal Fittings			26
To Disconnect Fused Silica Tubing From a SilTite Fitting			29

3 Maintaining the Split/Splitless Inlet

Consumables and Parts for the Split/Splitless Inlet	32
Exploded Parts View of the Split/Splitless Inlet 35
To Install a Capillary Column with the Split/Splitless Inlet		36
To Change the Septum on the Split/Splitless Inlet	40
To Clean the Septum Seat in the Insert Assembly of the Split/Splitless
Inlet 42
To Change the Liner and O-Ring on the Split/Splitless Inlet		44
To Replace the Gold Seal on the Split/Splitless Inlet	46

To Replace the Filter in the Split Vent Line 48

To Clean the Split/Splitless Inlet 49

To Bakeout Contaminants from the Split/Splitless Inlet 51

4 Maintaining the Purged Packed Inlet

Consumables and Parts for the Purged Packed Inlet 54

Exploded Parts View of the Purged Packed Inlet 57

To Install a Capillary Column with the Purged Packed Inlet 58

To Change the Septum on the Purged Packed Inlet 62

Maintaining Your GC

3

To Clean the Septum Seat in the Purged Packed Inlet 64

To Install an Adapter on the Purged Packed Inlet		66
To Change the O-Ring on the Purged Packed Inlet		68
To Change the Glass Liner on the Purged Packed Inlet			69
To Install an Insulation Cup on the Purged Packed Inlet			71
To Clean the Purged Packed Inlet	72
To Bakeout Contaminants from the Purged Packed Inlet			74
To Install a Packed Metal Column	75
To Install a Packed Column Adapter on a Detector Fitting			77
To Install a Packed Glass Column	79
To Condition a Packed Column	82

To Install Ferrules on a Packed Metal Column 84

5 Maintaining the COC Inlet

Consumables and Parts for the COC Inlet 86

Exploded Parts View of the COC Inlet	89
To Install a Capillary Column with the COC Inlet 90
To Check the Needle-to-Column Size on the COC Inlet 93
To Change a Septum on the COC Inlet	94
To Install an Insert on the COC Inlet	96
To Clean the COC Inlet 98

To Replace the Needle Support Assembly in a 7683B Injector 100

To Replace a Needle in a Syringe 103

To Replace the Fused Silica Needle in a Syringe for the COC Inlet 104 To Bakeout Contaminants from the COC Inlet 106

6 Maintaining the PTV Inlet

Consumables and Parts for the PTV Inlet 108
Exploded Parts View of the PTV Inlet 110
To Install a Capillary Column with the PTV Inlet	111
To Clean the Septumless Head on the PTV Inlet	114

To Replace the Septumless Head Teflon Ferrule on the PTV Inlet 117 To Change the Septum on the PTV Inlet 119

4	Maintaining Your GC

To Clean the Septum Seat in the Septum Head Assembly of the PTV

	Inlet 121
	To Change the Liner on the PTV Inlet				123
	To Replace the Inlet Adapter for the PTV Inlet 126
	To Replace the Filter in the Split Vent Line					128
	To Bakeout Contaminants from the PTV Inlet					129
7	Maintaining the VI
	Consumables and Parts for the VI			132
	Exploded Parts View of the VI		134
	To Install a Capillary Column with the VI				135
	To Attach a Sample Transfer Line to the VI					138
	To Remove the VI Interface		139
	To Clean the VI 140
	To Install the VI Interface 141
	To Replace the Filter in the Split Vent Line					142
	To Bakeout Contaminants from the VI Inlet					143
8	Maintaining the FID
	Consumables and Parts for the FID			146
	Exploded Parts Views of the FID			149
	Selecting an FID jet	151
	To Attach a Capillary Column Adapter on an Adaptable FID						153
	To Install a Capillary Column in the FID				155
	To Replace the FID Collector Assembly				158
	To Replace an FID Jet	160
	To Perform Maintenance on the FID Collector Assembly						163
	To Check the FID Leakage Current			171

To Check the FID Baseline 172

To Install the FID Insulation Cup Assembly (Adaptable FID Only) 173 To Install the Optional FID PTFE Chimney Insert 175

To Bakeout the FID 176

9 Maintaining the TCD

Consumables and Parts for the TCD 180

Maintaining Your GC

5

To Install a Capillary Column in the TCD 182

To Install the Optional TCD Capillary Column Adapter 184

To Install a Capillary Column with the Optional TCD Capillary Column

Adapter 185

To Bakeout Contaminants from the TCD 187

10 Maintaining the uECD
Important Safety Information About the uECD 190
Consumables and Parts for the uECD		192
Exploded Parts View of the uECD 194
To Replace the uECD Fused Silica Indented Mixing Liner and Install the
Makeup Gas Adapter	195
To Install a Capillary Column in the uECD 198
To Install the Detector Insulating Cup		200
To Bakeout the uECD	202

11 Maintaining the NPD
Consumables and Parts for the NPD	206
Exploded Parts View of the NPD 209
Selecting an NPD jet 210
To Attach a Capillary Column Adapter on an Adaptable NPD		212
To Install a Capillary Column in the NPD 214
To Replace the NPD Bead Assembly	217
To Maintain the NPD Collector, Ceramic Insulators, and Jet		222
To Check the NPD Leakage Current	228

12 Maintaining the FPD

Consumables and Parts for the FPD 230

Exploded Parts View of the FPD 232

To Install a Capillary Column Adapter in the FPD 233

To Attach a Capillary Column to the FPD		235
To Change the FPD Wavelength Filter		237
To Remove the FPD Vent Tube	240
To Replace the FPD Ignitor	242
To Install the FPD Vent Tube and Cover		244

6	Maintaining Your GC

13 Maintaining a Valve

Consumables and Parts for Valves 246
Exploded Parts View of GC Rotary Valves		247
To Replace a Gas Sampling Valve Loop 248
To Align a Rotary Valve Rotor	250
To Replace a Rotary Valve in the Valve Box		251
To Remove the Upper Valve Box	254
To Install the Upper Valve Box	256

Maintaining Your GC

7

8	Maintaining Your GC

Agilent 6890 Gas Chromatograph

Maintaining Your GC

1

About Maintaining the GC

Overview of Maintenance 10

Tools and Materials Required for Maintenance 12

Safety Information 14

Preparing the GC for Maintenance 15

This section provides an overview of the maintenance procedures included in this document. It also lists the tools needed for routine maintenance and the safety information one should be aware of before performing a maintenance task.

Agilent Technologies

9

1 About Maintaining the GC

Overview of Maintenance

This manual details the routine tasks needed to maintain the 6890 Gas Chromatograph (GC). The procedures assume a basic knowledge of tool use and of GC operation. Readers are, for example, expected to know how to:

•Safely turn devices on and off

•Load methods

•Change component temperatures, flows, and pressures

•Make typical pneumatic connections using Swagelok and other standard fittings

Where to find a procedure

Included in this manual are chapters on maintaining the following GC components:

•Capillary Columns

•Split/Splitless Inlet

•Purged Packed Inlet

•COC Inlet

•PTV Inlet

•Volatiles Inlet (VI)

•FID

•TCD

•uECD

•NPD

•FPD

•Valves

Each chapter includes:

•A list of the most commonly used consumables and parts for the component

•An exploded parts view of the component

•Detailed procedures for routine maintenance tasks associated with the component

10	Maintaining Your GC

About Maintaining the GC 1

Early Maintenance Feedback feature

The Agilent Lab Monitor & Diagnostic Software includes the capability to alert users of upcoming maintenance needs. This feature, called Early Maintenance Feedback, notifies users when a counter (such as a septum counter, jet cleaning counter, injection counter, or uECD wipe test counter) has reached the specified maintenance point. After performing the required maintenance, reset the applicable counter to resume using the Early Maintenance Feedback feature. Refer to the features provided by the Agilent Lab Monitor & Diagnostic Software for more details on this.

Maintaining Your GC

11

1 About Maintaining the GC

Tools and Materials Required for Maintenance

Table 1 lists the tools needed for most GC maintenance procedures. The specific tools required to perform a maintenance procedure are listed in step 1 of the procedure.

Table 1 Tools and materials for GC maintenance

Common tools

Wrench, angled, septum nut (19251-00100)*

Wrench, open-end, 1/4-inch and 5/16-inch (8710-0510)*

Wrench, open-end, 9/16-inch and 7/16-inch (8710-0803)*

Wrench, capillary inlet (G3452-20512)*

Flathead screwdriver

Column cutter, wafer (5181-8836, 4/pk)*

Driver, nut, 1/4-inch (8710-1561)*

T-20 Torx key (8710-1807) or screwdriver*

T-10 Torx key (8710-2140) or screwdriver*

3-mm hex key wrench (8710-2411)

Electronic flow meter(s) or bubble meter(s) capable of calibrated measurements at 1, 10, and 100 mL/min flow ranges.

Electronic leak detector

Magnifying loupe, 20X (430-1020)

Metric ruler

Bench vise (for setting Swagelok fittings)

Razor or sharp knife

Tweezers (8710-0007) or thin needle-nose pliers (8710-0004)

Needle-nose pliers

ESD wrist strap (for installing new components)

Gloves, heat-resistant (for handling hot parts)

Wooden cotton swab (for removing FID filters)

Tools and materials for cleaning procedures

Cleaning brushes—The FID cleaning kit (9301-0985) contains appropriate brushes for cleaning detectors and inlets

Cleaning brushes—(8710-1346) For cleaning split/splitless inlet split vent fitting, FID and collectors

12	Maintaining Your GC

About Maintaining the GC 1

Table 1 Tools and materials for GC maintenance (continued)

Jet cleaning wire (.010 inch)

Clean, lint-free cloth (to protect contamination-sensitive detector parts)

Small ultrasonic cleaning bath with aqueous detergent (for cleaning detector and inlet parts)

Gloves, clean, lint-free, nylon (large: 8650-0030, small: 8650-0029) (for handling contamination-sensitive parts)

Steel wool, 0- or 00-grade (for cleaning an inlet’s septum seating surfaces)

* Included with the GC ship kits

Maintaining Your GC

13

1 About Maintaining the GC

Safety Information

Before performing a maintenance task, read the important safety and regulatory information found in the 6890 User Information book.

14	Maintaining Your GC

About Maintaining the GC 1

Preparing the GC for Maintenance

Before most maintenance procedures, the GC must be made ready. The purpose of this preparation is to avoid damage to both the instrument (electronics, columns, etc.) and the user (shocks, burns).

Column and oven preparation

The main hazards here are temperature (burns) and column exposure to air.

•Cool the oven by changing its setpoint to 35 °C. This allows the oven fan to assist cooling.

•Leave the carrier gas flow On until the oven has cooled. This protects the column from oxygen damage.

Inlet preparation

We are concerned with the possibility of burns and air intrusion into the column.

•After the oven and columns have cooled, reduce all inlet flows to 0.0 and turn the temperatures Off.

•For inlet-only maintenance, leave all detectors at their normal setpoints except for the TCD filament, which should be turned Off.

•If the column is to be removed, cap both ends to keep air out.

Detector preparation

This is another burn hazard area, plus the possibility of damage to the very sensitive electronics.

Some detectors (uECD, FPD, NPD) require 12 hours or longer to stabilize from the detector-off condition.

•To cool the detector, reduce the temperature setpoint to 35 °C.

•Some detectors (FID, NPD, FPD) use high voltages. The high voltage supply is part of the electrometer. Turn it Off to disable the high voltage.

•The filament in the TCD will be damaged if exposed to air while hot. To protect the filament, turn it Off.

Maintaining Your GC

15

1 About Maintaining the GC

16	Maintaining Your GC

Agilent 6890 Gas Chromatograph

Maintaining Your GC

2

Maintaining Capillary Columns

Consumables and Parts for Columns	18
To Install a Capillary Column Hanger	19
To Condition a Capillary Column 20
To Cut a Loop from a Column 23
To Reverse a Column and Bakeout Contaminants 24
To Attach a Capillary Column Using SilTite Metal Fittings		26
To Disconnect Fused Silica Tubing From a SilTite Fitting		29

Agilent Technologies

17

2 Maintaining Capillary Columns

Consumables and Parts for Columns

See the Agilent catalog for consumables and supplies for a more complete listing, or visit the Agilent Web site for the latest information (www.agilent.com/chem/supplies).

Table 2 Nuts, ferrules, and hardware for capillary columns

Column id (mm)	Description	Typical use	Part number/quantity
.530	Ferrule, Vespel/graphite,	0.45-mm and 0.53-mm capillary	5062-3512 (10/pk)
	0.8-mm id	columns
	Ferrule, graphite, 1.0-mm id	0.53-mm capillary columns	5080-8773 (10/pk)
	Column nut, finger-tight (for	Connect column to inlet or detector	5020-8293
	0.53-mm columns)
.320	Ferrule, Vespel/graphite,	0.32-mm capillary columns	5062-3514 (10/pk)
	0.5-mm id
	Ferrule, graphite, 0.5-mm id	0.1-mm, 0.2-mm, 0.25-mm, and	5080-8853 (10/pk)
		0.32-mm capillary columns
	Column nut, finger-tight (for	Connect column to inlet or detector	5020-8292
	.100- to .320-mm columns)
.250	Ferrule, Vespel/graphite,	0.1-mm, 0.2-mm, and 0.25-mm	5181-3323 (10/pk)
	0.4-mm id	capillary columns
	Ferrule, graphite, 0.5-mm id	0.1-mm, 0.2-mm, 0.25-mm, and	5080-8853 (10/pk)
		0.32-mm capillary columns
	Column nut, finger-tight (for	Connect column to inlet or detector	5020-8292
	.100- to .320-mm columns)
.100 and .200	Ferrule, Vespel/graphite,	0.1-mm and 0.2-mm capillary	5062-3516 (10/pk)
	0.37-mm id	columns
	Ferrule, Vespel/graphite,	0.1-mm, 0.2-mm, and 0.25-mm	5181-3323 (10/pk)
	0.4-mm id	capillary columns
	Ferrule, graphite, 0.5-mm id	0.1-mm, 0.2-mm, 0.25-mm, and	5080-8853 (10/pk)
		0.32-mm capillary columns
	Column nut, finger-tight (for	Connect column to inlet or detector	5020-8292
	.100- to .320-mm columns)
All	Ferrule, no-hole	Testing	5181-3308 (10/pk)
	Capillary column blanking nut	Testing–use with any ferrule	5020-8294
	Column nut, universal	Connect column to inlet or detector	5181-8830 (2/pk)
	Column cutter, ceramic wafer	Cutting capillary columns	5181-8836 (4/pk)

18	Maintaining Your GC

Maintaining Capillary Columns

2

To Install a Capillary Column Hanger

	WA RN ING	Be careful! The oven may be hot enough to cause burns. If the
		oven is hot, wear heat-resistant gloves to protect your hands.
		Wear safety glasses to protect your eyes from flying particles
	WARNING
		while handling, cutting, or installing glass or fused silica capillary
		columns. Use care in handling these columns to prevent puncture
		wounds.
		1 Prepare the column and oven for maintenance. See
		“Preparing the GC for Maintenance” on page 15.
		2 Select either the front or back hanger position. (Hanger is
		shown in back position.)
		Front position
		Back position

3Insert the ends of the hanger into the slots in the selected position.

Maintaining Your GC

19

2 Maintaining Capillary Columns

To Condition a Capillary Column

1 Gather the following:

• One 7/16-inch, and 1/4-inch wrenches

• No-hole ferrule (See “Consumables and Parts for Columns” on page 18.)

• Column nut

		=
		Do not use hydrogen as the carrier for conditioning! It could vent
	WA RN ING
		into the oven and present an explosion hazard.
		2 Prepare the column and oven for maintenance. See
		“Preparing the GC for Maintenance” on page 15.
		Be careful! The oven and/or detector may be hot enough to cause
	WARNING
		burns. If the detector is hot, wear gloves to protect your hands.
		Wear safety glasses to protect your eyes from flying particles
	WARNING
		while handling, cutting, or installing glass or fused silica capillary
		columns. Use care in handling these columns to prevent puncture
		wounds.
		3 Install the column into the inlet using the new ferrules. See:
		• “To Install a Capillary Column with the Split/Splitless
		Inlet” on page 36
		• “To Install a Capillary Column with the Purged Packed
		Inlet” on page 58
		• “To Install a Capillary Column with the COC Inlet” on
		page 90
		• “To Install a Capillary Column with the PTV Inlet” on
		page 111
		• “To Install a Capillary Column with the VI” on page 135

20	Maintaining Your GC

Maintaining Capillary Columns

2

4 Cap the detector column fitting.

5 Set a minimum velocity of 30 cm/s, or as recommended by the column manufacturer. Let gas flow through the column at room temperature for 15 to 30 minutes to remove air.

6 Program the oven from room temperature to the maximum temperature limit for the column. Increase the temperature at a rate of 10 to 15 °C/min. Hold at the maximum temperature for 30 minutes.

7 Prepare the GC for maintenance. See “Preparing the GC for Maintenance” on page 15.

	WA RN ING	Be careful! The oven and/or detector may be hot enough to cause
		burns. If the detector is hot, wear gloves to protect your hands.
		Wear safety glasses to protect your eyes from flying particles
	WARNING
		while handling, cutting, or installing glass or fused silica capillary
		columns. Use care in handling these columns to prevent puncture
		wounds.
		8 Attach the column to the detector. For details, select your
		specific detector from the following list:
		• “To Install a Capillary Column in the FID” on page 155
		• “To Install a Capillary Column in the NPD” on page 214
		• “To Install a Capillary Column in the TCD” on page 182
		• “To Install a Capillary Column in the uECD” on page 198
		• “To Install a Capillary Column Adapter in the FPD” on
		page 233

Maintaining Your GC

21

2 Maintaining Capillary Columns

9Restore the analytical method.

•For FID or FPD, immediately turn off the flame.

•For NPD, immediately turn off the bead.

10After the GC becomes ready, wait 10 minutes, then ignite the detector flame or bead.

22	Maintaining Your GC

Maintaining Capillary Columns

2

To Cut a Loop from a Column

		1	Gather the following:
			• New ferrule(s) for the column inlet connection
			• Column cutter
		2	Prepare the inlets for maintenance. See “Preparing the GC
			for Maintenance” on page 15.
		Be careful! The oven and/or inlet may be hot enough to cause
	WA RN ING
		burns. If either is hot, wear heat-resistant gloves to protect your
		hands.
		Wear safety glasses to protect your eyes from flying particles
	WARNING
		while handling, cutting, or installing glass or fused silica capillary
		columns. Use care in handling these columns to prevent puncture
		wounds.
		3	Loosen the inlet column nut and remove the column from the
			inlet.
		4	Uncoil one loop of column from the column hanger.
		5	Cut the unwanted loop from the column.
		6	Install the column into the inlet using the new ferrules. See:
			• “To Install a Capillary Column with the Split/Splitless
			Inlet” on page 36

• “To Install a Capillary Column with the Purged Packed Inlet” on page 58

• “To Install a Capillary Column with the COC Inlet” on page 90

• “To Install a Capillary Column with the PTV Inlet” on page 111

• “To Install a Capillary Column with the VI” on page 135

Maintaining Your GC

23

2 Maintaining Capillary Columns

To Reverse a Column and Bakeout Contaminants

1 Gather the following:

• 1/4-inch wrench

• Column cutter

2 Prepare the GC for maintenance. See “Preparing the GC for Maintenance” on page 15.

	WA RN ING	Be careful! The oven and/or detector may be hot enough to cause
		burns. If the detector is hot, wear gloves to protect your hands.
		Wear safety glasses to protect your eyes from flying particles
	WARNING
		while handling, cutting, or installing glass or fused silica capillary
		columns. Use care in handling these columns to prevent puncture
		wounds.
		3 Disconnect the column from the inlet and detector.
		4 If necessary, cut a loop from the column. (See “To Cut a Loop
		from a Column” on page 23.) Do not attach the column to the
		inlet.
		5 Remove the column from the hanger and reverse its position
		(inlet and detector ends) and place the column back on the
		hanger.
		6 Attach the column to the inlet.
		Select your specific inlet from the following list:
		• “To Install a Capillary Column with the Split/Splitless
		Inlet” on page 36
		• “To Install a Capillary Column with the Purged Packed
		Inlet” on page 58
		• “To Install a Capillary Column with the COC Inlet” on
		page 90
		• “To Install a Capillary Column with the PTV Inlet” on
		page 111
		• “To Install a Capillary Column with the VI” on page 135
		7 Attach your column to the detector.
		Select your specific detector from the following list:
		• “To Install a Capillary Column in the FID” on page 155
		• “To Install a Capillary Column in the NPD” on page 214

24	Maintaining Your GC

Maintaining Capillary Columns

2

•“To Install a Capillary Column in the TCD” on page 182

•“To Install a Capillary Column in the uECD” on page 198

•“To Install a Capillary Column Adapter in the FPD” on page 233

8Set the column flow to the normal operating value, or set the capillary column gas velocity to 30 cm/s.

For split splitless, PTV, and VI inlets select split mode and set the split vent flow to 200 mL/min.

9Purge the column with carrier flow for at least 10 minutes before heating the oven.

10Set the inlet temperature to 300 °C or 25 °C above the normal operating temperature.

11Set the column oven 25 °C above the GC method final oven temperature to bake contaminants out of the inlet, mostly through the split vent. Do not exceed the column manufacturer’s maximum temperature limit.

12Bakeout for 30 minutes.

Maintaining Your GC

25

2 Maintaining Capillary Columns

To Attach a Capillary Column Using SilTite Metal Fittings

This procedure is used to attach a capillary column to a

Microfluidic splitter or switch or an Ultimate Union.

1 Gather the following:

• SilTite ferrules (see Table 3)

• Swaging nut for SilTite ferrules (G2855-20555)

• Two 1/4-inch open-end wrenches

• One 7/16-inch open-end wrench

• Column cutting tool (5181-8836)

• Internal nut (G2855-20530)

• Lint free gloves

Table 3 Available SilTite metal ferrule packages

Part number	SilTite ferrule description
5188-5361	For 0.2- to 0.25-mm columns
5188-5362	For 0.32-mm columns
5188-5363	For 0.53-mm columns

	CAU TI O N	Wear clean, lint-free gloves to prevent contamination of parts with
		dirt and skin oils.
		2 Pass the tubing end through the internal nut and SilTite
		ferrule leaving approximately 1 cm of fused silica tubing
		protruding beyond the ferrule. Thread the swaging nut onto
		the internal nut with the tube protruding.

26	Maintaining Your GC

Maintaining Capillary Columns

2

3Using two wrenches against each other, tighten the two nuts together a little at a time, occasionally checking to see if the ferrule is gripping the tube. When the ferrule just starts to grip, notice position of the nuts and then tighten one of the nuts by turning 45 to 60 degrees of rotation, but no more than 60 degrees (one flat).

4 Remove the swaging nut.

Maintaining Your GC

27

2 Maintaining Capillary Columns

5 Using a wafer column cutter, trim the tubing at the small end of the ferrule, leaving approximately 0.3 mm of tubing extending beyond the ferrule.

Check the end of the tube with a magnifier. The end of the tube need not be perfectly square, but should not have cracks that extend under the ferrule.

	NO TE	It is important that the tube end does not extend beyond 0.5 mm from the
		end of the ferrule.

6Insert the assembled ferrule and nut into the SilTite fitting. Tighten with a wrench by only 15 to 20 degrees of rotation.

28	Maintaining Your GC

Maintaining Capillary Columns

2

To Disconnect Fused Silica Tubing From a SilTite Fitting

Loosen and remove the internal nut. If tubing and ferrule do not come free, insert a pointed object (pen, paper clip) into the ferrule release hole and press firmly. You will hear a click as the ferrule releases.

The SilTite ferrule seal should remain leak-free for many disconnections and reconnections.

Maintaining Your GC

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2 Maintaining Capillary Columns

30	Maintaining Your GC