HP 5890 II Plus, 5890 II User Manual

Reference Manual

HP 5890 Series II and HP 5890 Series II Plus

Hewlett-Packard Company 1989,1990, 1991, 1993, 1994

HP part number 05890-90271

First edition—Jun 1989

Printed In U.S.A. Second edition—Oct 1989 Printed In U.S.A. Third edition—Jan 1990 Printed In U.S.A. Fourth edition—Oct 1990 Printed In U.S.A. Fifth edition—Oct 1991 Printed In U.S.A. Fifth edition—Mar 1993 Printed In U.S.A. Sixth edition—Jul 1994 Printed In U.S.A.

Printed in USA

Warranty The information contained

in this document is subject to change without notice.

Hewlett-Packard makes no warranty of any kind with regard to this material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. Hewlett-Packard shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.

Safety Information The HP 5890 Series II and

HP 5890 Series II Plus are IEC (International Electrotechnical Commission) Safety Class 1 instruments. This unit has been designed and tested in accordance with recognized safety standards. Whenever the safety protection of the HP 5890 Series II has been compromised, disconnect the unit from all power sources and secure the unit against unintended operation.

Safety Symbols This manual contains

safety information that should be followed by the user to ensure safe operation.

WARNING

A warning calls attention to a condition or possible situation that could cause injury to the user.

CAUTION

A caution calls attention to a condition or possible situation that could damage or destroy the product or the user’s work.

Important User Information for In Vitro Diagnostic Applications

This is a multipurpose product that may be used for qualitative or quantitative analyses in many applications. If used in conjunction with proven procedures (methodology) by qualifiedoperator, one of these applications may be In Vitro Diagnostic Procedures.

Generalized instrument performance characteristics and instructions are included in this manual. Specific In Vitro Diagnostic procedures and methodology remain the choice and the responsibility of the user, and are not included.

Sound Emission Certification for Federal Republic of Germany

If Test and Measurement Equipment is operated with unscreened cables and/or used for measurements in open set-ups, users have to assure that under these operating conditions the Radio Interference Limits are still met at the border of their premises.

The following information is provided to comply with the requirements of the German Sound Emission Directive dated January 18, 1991

Sound pressure Lp < 70db(A)

During normal operation At the operator position According to ISO 7779

(Type Test) When operating the HP

5890 Series II with cryo valve option, the sound pressure cryo valve operation for short burst pulses.



78 db(A) during

Schallemission Werden Meß- und

Testgeräte mit ungeschirmten Kabeln und/oder in offenen Meßaufbauten verwendet, so ist vom Betreiber sicherzustellen, daß die Funk-Entströbedingungen unter Betriebsbedingungen an seiner Grundstücksgrenze eingehalten werden.

Diese Information steht im Zusammenhang mit den Anforderungen der Maschinenl

sverordnung vom 18 Januar 1991.

Schalldruckpegel LP < 70 dB(A)

Am Arbeitsplatz Normaler Betrieb Nach DIN 45635 T. 19

(Typpr Bei Betrieb des HP 5890

Serie II mit Cryo Ventil Option treten beim Oeffnen des Ventils impulsfoermig Schalldrucke Lp bis ca. 78 dB(A) auf.

ärminformation

üfung)

Little Falls Site

Chapter 1 — Columns and Fittings 9.................

Column oven 11..........................................................

Column placement 12.................................................

Packed column 12....................................................

Hewlett•Packardcapillary columns 13..................................

Fittings 14...............................................................

Liners/adapters and inserts, general 17....................................

Inlet/detector liners/adapters 20...........................................

Packed column inlet liners 20..........................................

Detector liners/adapters 22............................................

ECD and TCD adapters 23............................................

Liner/adapter installation 24..........................................

Inlet inserts 25...........................................................

Packed column inlet inserts 25.........................................

Split/splitlessor split•onlycapillary inlet inserts 27......................

Jet replacement, FIDs or NPDs 30.........................................

Metal capillary columns 30................................................

Chapter 2 — Keyboard and Displays 31...............

Displaying setpoints 33...................................................

Entering setpoints 34.....................................................

Keyboard operation, INET control 37......................................

Protecting setpoints 38...................................................

Loading default setpoints 39..............................................

Chapter 3 — Temperature Control 43.................

Valid setpoint ranges 46..................................................

Cryogenic (sub•ambient)oven control 47...................................

Programming oven temperature 49........................................

Oven status 50...........................................................

Oven safety 51...........................................................

Fault: messages 52.......................................................

After a power failure . . . 53...............................................

Oven temperature calibration 54..........................................

Contents

Chapter 4 — Electronic Flow Sensing 57...............

Displaying gas flow rate 58...............................................

Designating gas type 59..................................................

Electronic flow sensor (EFS) calibration 60.................................

Preparation 61.......................................................

Setting the zero calibration value 61...................................

Setting the GAIN calibration value 63..................................

Entering specific ZERO and GAIN values 65............................

Chapter 5 — Signal Output 67........................

Zeroing signal output 68..................................................

Displaying current setpoint 69........................................

Self• setpoint 70......................................................

User•defined setpoint 72..............................................

Signal attenuation 72.....................................................

Displaying current

RANGE 2!()

Entering / setpoints 76..............................................

Switching off the +1 mV output 76.....................................

Test signal output 77.....................................................

Instrument network (INET) 79............................................

The controller 79.....................................................

An instrument 81.....................................................

Active workspace 82..................................................

HP 5890 INET states 82...............................................

INET operation 83....................................................

Automatic INET reconfiguration 85....................................

INET configuration 85....................................................

Switching between Global and Local 86.................................

INET/HP•ILaddresses 87.............................................

HP•ILloopback test 90...................................................

Warn: and fault: messages 92.............................................

File compatibility with data handling devices 94............................

What are the modes? 94...............................................

What is the proper mode for my data handling device? 94................

How do I know in which mode my GC is configured now? 94..............

How do I change modes? 95............................................

How to convert HP 339X Integrator workfiles from 5890A

to SERIES II mode: 97.............................................

ATTN 2!()

setpoints 75..............

Contents

Chapter 6 — Inlet Systems 99.........................

Packed column inlet 100...................................................

Electronic flow sensor 102..............................................

Septum•purgedpacked column inlet 103.................................

Problems at high inlet temperatures 104.................................

A thermally optimized high•temperatureinlet 104........................

Septum purge 105.....................................................

Electronic flow sensor 106..............................................

Split/splitlesscapillary inlet 107............................................

Carrier gas considerations 108..........................................

Initial column head pressure 110........................................

Split sampling 111.....................................................

Splitless sampling 114.................................................

Injection technique, split/splitless sampling 121..........................

Chapter 7 — Detector Systems 123.....................

Capillary makeup gas flow rate 124.........................................

FID and NPD jets 125.....................................................

Flame ionization detector (FID) 126.........................................

FID flameout problems 128.............................................

Nitrogen•phosphorusdetector (NPD) 129....................................

Performance considerations 132.........................................

Electron capture detector (ECD) 135........................................

Requirements for USA owners 135......................................

Temperature 140......................................................

Background level 141..................................................

Thermal conductivity detector (TCD) 143....................................

Optimizing performance 146............................................

Analyzing for hydrogen, special considerations 148.......................

TCD•to•FIDseries connection 149.......................................

Filament passivation 149...............................................

Capillary column considerations 150....................................

Flame photometric detector (FPD) 151......................................

Optimizing FPD sensitivity and selectivity 151...........................

Flame ignition problems 153............................................

Contents

Chapter 8 — Preventive Maintenance 155..............

Conditioning columns 156..................................................

(Re)Packing columns 158..................................................

Packed column inlet 159...................................................

Changing septa 159....................................................

Insert/liner care 160...................................................

Leaks 160.............................................................

Cleaning 162..........................................................

Split/splitlesscapillary inlets 163...........................................

Changing septa 163....................................................

Insert care 164........................................................

Leaks 165.............................................................

Cleaning 168..........................................................

Liner and/or insert care 169................................................

Glass inserts 169......................................................

Repacking a split insert 170............................................

Metal inserts and/or liners 171..........................................

Flame ionization detector (FID) 171.........................................

Jet exchange/replacement 172..........................................

Cleaning 173..........................................................

Ignition problems 177..................................................

Nitrogen•phosphorusdetector (NPD) 178....................................

Cleaning 178..........................................................

Removing/replacing the NPD collector 181...............................

Type B NPD transformer/collector assembly 184..........................

Reinstallation 186.....................................................

Electron capture detector (ECD) 188........................................

Frequency test 188....................................................

Carrier gas evaluation 188.............................................

Leaks 189.............................................................

Thermal cleaning 190..................................................

Packed column: 191....................................................

Capillary column: 191..................................................

Radioactivity leak test (wipe test) 192...................................

Thermal conductivity detector (TCD) 192....................................

Cleaning 192..........................................................

Flame photometric detector 193............................................

Cleaning/replacing FPD windows, filters, seals 193.......................

Cleaning/replacing the FPD jet 197.....................................

FPD leak testing (GC with electronic flow sensor) 198....................

FPD leak testing (GC without electronic flow sensor) 199.................

Conditioning chemical traps 200............................................

Contents

Chapter 9 — Chromatographic Troubleshooting 201......

Introduction 202..........................................................

Baseline symptoms 202....................................................

Position 202...........................................................

Wander and drift 203..................................................

Noise 204.............................................................

Spiking 206...........................................................

Retention time symptoms 207..............................................

Retention time drift 207................................................

Retention time wander (reproducibility) 207.............................

Peak symptoms 209.......................................................

No peaks 209..........................................................

Inverted peaks 209....................................................

Extra peaks 209.......................................................

Deformed peaks 211...................................................

Troubleshooting valve systems 214..........................................

Chromatographic symptoms 214........................................

Locating leaks 216........................................................

Pressure check 217........................................................

Electronic pressure control 218.............................................

Safety shutdown 219...................................................

Proper configuration 220...............................................

Switch setting examples 221............................................

Chapter 10 — Test Sample Chromatograms 223........

Test sample chromatograms 225............................................

Index 241.............................................

This page intentionally left blank.

Columns and Fittings

The HP 5890 SERIES II (hereafter referred to as HP 5890) provides flexibility in choices among inlets, columns, and detectors through use of liners and adapters, allowing any standard column to be used without sacrificing performance. Additionalflexibility is gained through positions of inlets and detectors relative to each other and through the large internal volume of the oven.

This section provides information for the following:

The column oven.

Fittings.

Liners and inserts.

ECD and TCD capillary makeup gas adapters.

The first three items must be considered before a column may be installed properly at either an inlet or a detector. In addition, for an FID or NPD, and depending upon the column to be installed (packed versus capillary), the correct jet must be installed before installing the column. Jet installation is described in Chapter 8, Preventive Maintenance.

For specific information on ordering fittings, liners, and inserts, see

Hewlett•Packard's analytical supplies catalog.

Columns and Fittings

Column oven

Figure 1-1

Inlet Ftg

Nut Plate

The Column Oven

The oven door latch, located beneath the lower right corner of the door, is pressed upward to open the door.

Motor•drivenflapsat the rear of the oven admit room air for cool down or

near•ambientoperation, so the door is kept closed except for access to columns (the oven cools most efficiently with its door closed).

Det Ftg

The oven can maintain temperature down to about 7

C above ambient without auxiliary cooling. If lower temperatures are required, a cryogenic valve (for either liquid CO

or liquid N1) is needed. Liquid CO permits reliable temperature control down to -50^C; liquid N1provides reliable control down to -80 450

C. The maximum oven temperature is

Columns and Fittings

Column oven

Column placement

Generally, a column may be installed between any inlet and detector. A rigid1/4•inchpacked glass column, however, if installed in the B

(rear•most)inlet, can only be installed in the B (rear•most)detector. Distance relationships among inlets and detectors are shown in Figure 1•2.

Figure 1-2

Top View

(showing relationshipof inlets to detectors)

Front

Installation Restrictions, Rigid Columns

1mm

228 +

Packed column

Packed columns require no physical support other than that provided by proper installation at inlet and detector fittings.

Columns and Fittings

Column oven

Hewlett-Packard capillary columns

Hewlett•Packardcapillary columns are wound on wire frames which mount on a pair of brackets which slip into slots at the top of the oven interior.

Figure 1-3

Typical Hewlett-Packard Capillary Columns

Columns and Fittings

Fittings

Figure 1-4.

Column Hanger

Part No. 1460-1914

Installed Bracket for Hewlett-Packard Capillary Columns

Column Installed

The bracket has two positions from which to hang the column wire frame. Depending upon frame diameter, use the position which best centers the column in the oven. Column ends should come off the bottom of the frame, making smooth curves to inlet and detector fittings. Avoid allowing any section of the column itself to come in contact with oven interior surfaces.

Fittings

The following is a brief comparison of common types of fittings (nuts, ferrules, O•rings)used to install columns, and to install inlet and detector

liners and/or inserts. Each type has its own set of advantages and disadvantages:

Columns and Fittings

Fittings

Graphite O•ringsor ferrules have excellent sealing quality and long service life, can be used continuously to 400

C, and are generally recommended for most applications, particularly capillary and glass columns. They are also recommended for inlet and detector liners, and for split/splitlesscapillary inlet inserts.

Since they do not adhere permanently to glass or metal, they can be removed easily without damage to the column, tubing, liner, or insert. A rear metal ferrule may be needed if recommended by the manufacturer.

Commonly used with metal columns and tubing, brass nuts and ferrules on the column prevent damage to inlet and detector liners, but may develop leaks above 250

C or with temperature

programming. Also commonly used with metal columns and tubing, stainless steel

fittings minimize possibility of leakage at high temperature, but require care in installing columns; overtightening may damage the column end or inlet/detector fitting.

Teflon ferrules may be used to 250^C but are recommended only for isothermal work, because they develop leaks when temperature•programmed.

Commonly used with glass columns, Vespel (or graphite•filledVespel) ferrules are reusable and work well to 350

C. These ferrules may

leak or crack if tightened when cold.

Glass columns can be installed using silicone O•rings. For O•ring installation, a back metal ferrule, reversed, is necessary to provide a flat surface to seal against.

Silicone O•ringsare useful to about 250

C, but, due to bleed, interfere in high•sensitivitywork. They also gradually lose elasticity and crack, so they must be replaced fairly often.

Columns and Fittings

Fittings

Table 1-1. Typical Fittings for Columns and Inlet/Detector Liners, Adapters, and Inserts

Type Description Typical Use Part No.

1/4-inch swage, nut 1/4-inch packed metal columns 5080-8753 stainless steel, front ferrule pkg, 20 of each back ferrule

1/8-inch swage, nut 1/8-inch packed metal columns 5080-8751 stainless steel, front ferrule pkg, 20 of each back ferrule

1/4-inch swage, nut 1/4-inch packed metal columns 5080-8752 brass, pkg, front ferrule 20 of each back ferrule

1/8-inch swage, nut 1/8-inch packed metal columns 5080-8750 brass, pkg, front ferrule 20 of each back ferrule

Vespel, 1/4-inch ferrule inlet/detector liners, 5080-8774 pkg of 10 1/4-inch glass packed columns

Vespel, 1/8-inch ferrule metal columns 0100-1107 pkg of 10

graphite, 1.0-mm ferrule capillary columns 5080-8773 pkg of 10

graphite, 0.5-mm ferrule capillary columns 5080-8853 pkg of 10

graphite 6.35-mm O-ring inlet/detector liners, 0905-0767

1/4-inch glass packedcolumns,

split capillary inlet insert graphite 6.52-mm O-ring splitless capillary inlet insert (use) 0905-1004 silicone 6.0-mm O-ring inlet/detector liners 0905-0322

1/4-inch glass packedcolumns,

split/splitless capillaryinlet inserts silicone 1.0 mm O-ring capillary columns 0905-0759 Note: Dimensions given are id’s of the O-ring or ferrule.

Columns and Fittings

Liners/adapters and inserts, general

A liner/adapter is installed from below, inside the oven; it serves both as an adapter to mate the particular column to the inlet or detector and to provide correct internal volume for proper operation.

Inserts are used with inlets only, and, when required, are installed from above, at the top of the inlet; these are discussed specificallylater in this section (see Inlet inserts).

In general, the analysis to be performed determines the column to be used. The column then dictates hardware required for the inlet and detector (liner, insert, adapter, jet (FID or NPD)).

Note:

A correctly designed 1/4•inchpacked glass column requires no liners since the column ends themselves serve this purpose.

The appropriate liner/adapter, and insert if required, must be installed prior to installing a column.

Tables 1•2and 1•3summarize hardware required for various combinations of inlets, columns, and detectors.

Columns and Fittings

Liners/adapters and inserts, general

Table 1-2. Hardware and Recommended Fittings for Packed Column Installation

Packed Columns

1/8-inch Metal 1/4-inch Metal 1/4-inch Glass

Recommended 1/8-inch 1/4-inch 1/4-inch swage- Column Fittings swage-type nut swage-type nut type nut and

and ferrules

graphic ferrule or silicone O-ring(s)

Packed Column 19243-80510

19243-80520

Inlet Liners or or

19243-80530

19243-80540

(requires glass insert) (requires glass insert)

FID/NPD

19231-80521

19231-80530

Liners/Adapters

TCD Liners/Adapters None 19302-80020

ECD Liner/Adapters 19301-80530

Use 1/4-inch swage-typenut and Vespel or graphite ferrule to install liner/adapter.

See Chapter8 for details regardingjet exchange(if necessary).

See information later in this chapter regarding proper installation of swage-type fittingson packed metal columns.

None None

None

19302-80020 (may require altering the column)

Columns and Fittings

Liners/adapters and inserts, general

Table 1-3. Hardware and Recommended Fittings for Capillary Column Installation

Capillary Columns

HP Series 530

320¿m ID 200¿m ID Metal/

Glass

Recommended Capillary column Capillary column Same as 320¿m Same as Column Fittings nut and 1.0-mm nut and 0.5-mm HP Series

graphite ferrule, or graphite or 530

silicone O-ring(s) silicone O-ring(s)

Packed Column 19244-80540

Not Not Not

Inlet Liners (requires glass Recommended Recommended Recom-

insert) mended

Split/Splitless & 18740-60840 Same Same Same Split-Only with graphiteor Capillary Inlet silicone O-ring Split Sampling

Split/Splitless 18740-80220 Same Same Same Capillary Inlet with graphite or Insert: Splitless silicone O-ring Sampling

Programmable 19245-20580

19245-20520 19245-20510 19245-

On-Column 20550 Capillary Inlet Insert

FID/NPD

19244-80550

Same Same Same

Liners/Adapters TCD 18740-20950 19232-80550

Same Same

Liners/Adapters and

18740-20960

ECD 19244-805501,

19233-80530 Same Same

Liners/Adapters

Use 1/4-inch swage-typenut (if a nut is notsuppliedas part ofthe adapter) and graphite or Vespel ferrule to install liner/adapter.

0.11-inch jet must beused; see Chapter8 for informationregarding jet exchange (if necessary).

Use only if detector is not configured with capillary makeupgas adapter. If makeup adapter is provided,it is used instead (usually with makeup gas turnedoff).

Columns and Fittings

Inlet/detector liners/adapters

Interchangeable stainless steel liners/adapters, installed from inside the oven, are used with the packed column inlet, and with all detectors, depending upon the column to be installed.

Packed column inlet liners

Figure 1-5

Liner

Installed Liner, Packed Column Inlet

Liners for the packed column inlet are available in three sizes: one for

1/8•inchcolumns, one for 1/4•inchcolumns, and one for HP Series 530

capillary columns.

Columns and Fittings

Inlet/detector liners/adapters

In addition, liners for the packed column inlet are available to accept glass inserts (discussed later) for reduced reactivity, to trap nonvolatile residues, or for use with an HP Series 530

No liner is used with 1/4•inchpacked glass columns. The long leg of the column fits into the inlet body, replacing the liner. Packing and glass wool plug must be below the tip of the needle for best results.

Metal columns are installed with a liner appropriate for the column diameter.

If necessary, glass columns can be installed using a metal liner (preferably those accepting a glass insert), but this is not recommended. There may be problems with dead volume in connections, and preventing contact of sample with metal surfaces.

capillary column.

Columns and Fittings

Inlet/detector liners/adapters

Detector liners/adapters

Figure 1-6

Liner/Adapter

Typical Installed Detector Liner/Adapter

Detectors require a liner/adapter to be installed when used with packed metal columns (either 1/8•or 1/4•inch),and with any type of capillary

column. Normally, no liner is required with 1/4•inchpacked glass columns, since the leg of the column itself serves as the liner.

For the FID or NPD, the correct detector jet must be installed prior to installation of the liner. (If jets must be exchanged, see Chapter 8, Preventive Maintenance.)

Columns and Fittings

Inlet/detector liners/adapters

ECD and TCD adapters

A makeup gas adapter must be installed in the ECD or TCD base to install a capillary column, and to augment carrier flow through the column with additional gas flow needed for optimal detector operation. The adapter must be removed for packed column applications.

In addition, to install an HP Series 530

capillary column in an ECD or TCD having no capillary makeup gas adapter, the following adapters are used: Part No. 19244•80550for the ECD, and Part No. 18740•20950and

18740•20960for the TCD. Finally, to use a 1/4•inchcolumn with the TCD (having a base designed

for 1/8•inchcolumns), a 1/8•to 1/4•inchadapter is required (Part No. 19302•80020). For the ECD (having a base designed for 1/4•inch columns), to use a 1/8•inchcolumn, a 1/4•to 1/8•inchadapter is required (Part No. 19301•80530).

Columns and Fittings

Inlet/detector liners/adapters

Liner/adapter installation

Figure 1-7

Liner

1/4-inch Ferrule

Liner Retainer Nut

Capillary Column Nut

WARNING

Packed Column Inlet Liner for HP Series 530 Capillary Column Use

Nut and Ferrule Installed on a Liner/Adapter

1-mm Graphite Ferrule

With one exception, liners/adapters are installed in the same manner; if the liner/adapter has not been used before, a new ferrule must be installed.

The single exception is the adapter to install an HP Series 530

capillary

column in a TCD without provision for capillary makeup gas (Part No.

18740•20950and 18740•20960). In this case, no ferrule is required to form a seal with the detector base.

Note: A graphite ferrule is strongly recommended; since metal ferrules tend to lock permanently onto the liner/adapter, their use may require replacing the entire liner/adapter, should a permanent leak develop.

Exercise care! The oven, and/or inlet or detector fittings may be hot enough to cause burns.

Note: The liner/adapter must be kept as clean as possible to prevent introducing contamination into the inlet or detector. Use a clean, lint•freecloth to remove fingerprints, etc., from the end of the liner/adapter to be inserted into the inlet or detector base. CH

(methanol) may be used as a solvent.

Columns and Fittings

Inlet inserts

1. Assemble a brass nut and graphite ferrule onto the liner/adapter.

2. Insert the liner/adapter straight into the detector base as far as

3. Holding the liner/adapter in this position, tighten the nut finger•tight.

4. Use a wrench to tighten the nut an additional 1/4 turn.

5. Install the column; then heat the oven, inlet, and detector to desired

Inlet inserts

Inserts are used in inlets, and can be installed from the top of the particular inlet.

Packed column inlet inserts

possible.

operating temperatures and, only if necessary to stop leaks, tighten fittings further.

Figure 1-8

Flared End

Glass Insert for Packed Column Inlet Liner

Assuming the correct inlet liner is installed, a glass insert is installed as described on the next page.

Columns and Fittings

Inlet inserts

WARNING

Figure 1-9

Exercise care! the oven, and/or inlet, or detector fittings may be hot enough to cause burns.

Flared End

Insert

Installing a Glass Insert in a Packed Column Inlet

1. In handling the insert, avoid contaminating its surface (particularly

its interior).

2. Remove the septum retainer nut and septum.

3. Carefully remove the old insert (if present) by withdrawing it straight

up. A match stick or similar fibrous item may be used as an aid in lifting the insert from the inlet.

4. Install the new insert by dropping it carefully, straight into the inlet

liner, flared end up.

Columns and Fittings

Inlet inserts

Note: For the liner and insert for an HP Series 530¿capillary column, if the column is already installed, a new insert may not seat properly in the liner; the column may prevent it from dropping completely into the liner.

If the insert does not drop completely into the liner, do not force it (either the liner or the column may shatter); instead, remove the column, seat the insert, and then replace the column.

5. Replace the septum and septum retainer nut.

Split/splitless or split-only capillary inlet inserts

Figure 1-10

Viton O-ring (Preferred) Viton O-ring

Split Use Splitless Use

Split/Splitless and Split-Only Capillary Inlet and Inserts

A specific inlet insert is required, depending upon the particular sampling mode. Specific sampling modes include:

Split, for major•componentanalyses

Purged splitless, for trace•componentanalyses

Columns and Fittings

Inlet inserts

The split insert contains packing material (10% OV•1on 80/100 High Performance Chromosorb•W),held in place by silanized glass wool plugs, located immediately above a mixing chamber. This ensures proper volatilization and homogeneous mixing of the sample prior to its entry into the column.

WARNING

Caution

Exercise care! The oven, and/or inlet, or detector fittings may be hot enough to cause burns.

If operating in split mode, carrier gas pressure must be reduced before opening the inlet. If not done, pressure may blow insert packing out of the inlet, altering its characteristics. Pressure is reduced at the backpressure regulator for the inlet.

1. In handling the insert, avoid contaminating its surface (particularly

its interior).

2. Remove the insert retainer nut. The septum retainer nut need not be

removed from the insert retainer nut assembly.

Columns and Fittings

Inlet inserts

Figure 1-11

Caution

Installation, Split/Splitless Capillary Inlet Insert

3. Using tweezers, forceps, or similar tool, remove any insert already in

place.

4. Inspect the new insert to be installed: For a split mode insert, the end

with the mixing chamber and packing is inserted first into the inlet.

5. Place a graphite or silicone O•ringon the insert, about 2 to 3 mm from

its top end.

6. Install the insert, pressing it straight down, as far as possible, into

the inlet.

Do not add any seal either at the bottom of the inlet or at the bottom of the insert; to do so will damage the inlet and/or shatter the insert.

7. Replace the insert retainer nut, tightening it to firm finger•tightness

to form a leak•freeseal. Do not overtighten.

Columns and Fittings

Jet replacement, FIDs or NPDs

Depending upon the column type (packed versus capillary) to be used, and/or analyses to be performed, exchanging the jet in an FID or NPD may be necessary. This must be done prior to column installation, and is particularly important in optimizing FID performance.

Exchanging the jet in either an FID or an NPD is described in Chapter 8, Preventive Maintenance.

Metal capillary columns

Most metal capillary columns (0.6 to 1.0 mm od) can be connected directly. Some metal capillaries have a large•diametersleeve soldered on

each end; this must be removed. Use a small triangular file to score the tubing behind the sleeve; then bend the sleeve back and forth until it breaks.

It is important to have fresh ends of the column, free of burrs, jagged edges, and/or loose particles of column, stationary phase, and/or material from a sealing ferrule or O•ring.

Therefore, whenever the column must be cut to provide fresh ends, use a suitable file to first score the column at the point at which it is to be broken. This is done normally after installing on the column the column nut and ferrule (or O•ring)required for installation.

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