Agilent Technologies G6600-90006 User Manual

Agilent 355 Sulfur and 255 Nitrogen Chemiluminescence Detectors

Operation and Maintenance Manual

Agilent Technologies

Notices

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.

Acknowledgements

Torx® is a registered trademark of Textron Inc.; Teflon® is a registered trademark of E.I. du Pont de Nemours and Company. Kimwipe® is a registered trademark of the Kimberly-Clark Corporation.

Manual Part Number

G6600-90006

Edition

First edition, June 2007 Replaces G6600-90002

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.

Technology Licenses

The hardware and/or software described in this document are furnished under a license and may be used or copied only in accordance with the terms of such license.

Restricted Rights Legend

defined in FAR 2.101(a) or as “Restricted computer software” as defined in FAR

52.227-19 (June 1987) or any equivalent agency regulation or contract clause. Use, duplication or disclosure of Software is subject to Agilent Technologies’ standard commercial license terms, and non-DOD Departments and Agencies of the U.S. Government will receive no greater than Restricted Rights as defined in FAR

52.227-19(c)(1-2) (June 1987). U.S. Government users will receive no greater than Limited Rights as defined in FAR 52.227-14 (June 1987) or DFAR 252.227-7015 (b)(2) (November 1995), as applicable in any technical data.

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.

If software is for use in the performance of a U.S. Government prime contract or subcontract, Software is delivered and licensed as “Commercial computer software” as defined in DFAR 252.227-7014 (June 1995), or as a “commercial item” as

Warnings

English

WARNING

This symbol on the instrument indicates that the user should refer to the manual for operating instructions.

Any operation requiring access to the inside of the equipment, could result in injury. To avoid potentially dangerous shock, disconnect from power supply before opening the equipment.

For continued protection against fire hazard replace fuse with same type and rating.

This symbol indicates that to comply with European Union Directive 2002/96/EC for waste electrical and electronic equipment (WEEE), the Analyzer should be disposed of separately from standard waste.

WARNING

Operation and Maintenance Manual 3

This is a safety Class I product. It must be wired to a mains supply with a protective earthing ground incorporated into the power cord. Any interruption of the protective conductor, inside or outside the equipment, is likely to make the instrument dangerous. Intentional interruption is prohibited.

If this instrument is used in a manner not specified by Agilent, the protection provided by the instrument may be impaired.

High voltage is present in the instrument when the power cord is connected, even if the main power switch is in the standby mode. To avoid potentially dangerous shock, disconnect the power cord before removing the side panels.

WARNING

Ozone is a hazardous gas and a strong oxidant. Exposure to ozone should be minimized by using the instrument in a well-ventilated area and by venting the exhaust of the vacuum pump to a fume hood. The ozone generator should be turned off when the instrument is not in use.

WARNING

Burner temperature Is extremely hot. Do not touch. Allow to cool before servicing.

Hydrogen is an extremely flammable gas. Use appropriate care when handling. Inspect all connections with a suitable leak detector.

Oxygen rich environments can promote combustion and even result in spontaneous combustion under conditions of high pressure and exposure to contamination. Use only oxygen rated components and ensure that components are oxygen clean prior to use with pure oxygen.

Exceeding the gas inlet pressure of 25 psig (1.72 bar) may damage the hydrogen and oxidant sensors or burst their connective tubing.

4 Operation and Maintenance Manual

Español

WARNING

Cualquier operación que requiera acceso al interior del equipo, puede causar una lesión. Para evitar peligros potenciales, desconectarlo de la alimentación a red antes de abrir el equipo.

Para protección contínua contra el peligro de fuego, sustituir el fusible por uno del mismo tipo y características.

Este símbolo en el instrumento indica que el usuario debería referirse al manual para instrucciones de funcionamiento.

Esto es un producto con clase I de seguridad. Debe conectarse a una red que disponga de tierra protectora en el cable de red. Cualquier interrupción del conductor protector, dentro o fuera del equipo, puede ser peligroso. Se prohibe la interrupción intencionada.

WARNING

Si este instrumento se usa de una forma no especificada por Agilent, puede desactivarse la protección suministrada por el instrumento.

Operation and Maintenance Manual 5

Français

WARNING

Chaque opération à l'intérieur de l'appareil, peut causer du préjudice. Afin d'éviter un shock qui pourrait être dangereux, disconnectez l'appareil du réseau avant de l'ouvrir.

Afin de protéger l'appareil continuellement contre l'incendie, échangez le fusible par un fusible du même type et valeur.

Le symbol indique que l'utilisateur doit consulter le manuel d'instructions.

Ceci est un produit de Classe de sécurité I. L'instrument doit être branché sur l'alimentation secteur par un fil de secteur prévu d'une prise de masse. Chaque interruption du conducteur protégeant, à l'intérieur ou á l'extérieur de l'appareil peut rendre l'instrument dangereux. Interruption intentionnelle est interdite.

WARNING

Si l'instrument n'est pas utilisé suivant les instructions de Agilent, les dispositions de sécurité de l'appareil ne sont plus valables.

6 Operation and Maintenance Manual

Deutsch

WARNING

Vor dem Öffnen des Gerätes Netzstecker ziehen!

Für kontinuierlichen Schutz gegen Brandgefahr dürfen bei Sicherungswechsel nur Sicherungen der gleichen Stärke verwendet werden!

Dieses Symbol auf dem Gerät weist darauf hin, dass der Anwender zuerst das entsprechende Kapitel in der Bedienungsanleitung lesen sollte.

Dies ist ein Gerät der Sicherheitsklasse I und darf nur mit einem Netzkabel mit Schutzleiter betrieben werden. Jede Unterbrechung des Schutzleiters au erhalb oder innerhalb des Gerätes kann das Gerät elektrisch gefährlich machen. Absichtliches Unterbrechen des Schutzleiters ist ausdrücklich verboten.

WARNING

Wenn das Gerät nicht wie durch die Firma Agilent, vorgeschrieben und im Handbuch beschrieben betrieben wird, können die im Gerät eingebauten Schutzvorrichtungen beeinträchtigt werden.

Operation and Maintenance Manual 7

Italiano

WARNING

Qualsiasi intervento debba essere effettuato sullo strumento può essere potenzialmente pericoloso a causa della corrente elettrica. Il cavo di alimentazione deve essere staccato dallo strumento prima della sua apertura.

Per la protezione da rischi da incendio in seguito a corto circuito, sostituire I fusibili di protezione con quelli dello stesso tipo e caratteristiche.

Il simbolo sullo strumento avverte l'utilizzatore di consultare il Manuale di Istruzioni alla sezione specifica.

Questo strumento è conforme alle specifiche per I prodotti in Classe I - Il cavo di alimentazione dalla rete deve essere munito di "terra". Qualsiasi interruzione del cavo di terra all'interno ed all'esterno dello strumento potrebbe risultare pericolòsa. Sono proibite interruzioni intenzionali.

WARNING

Se questo strumento viene utilizzato in maniera non conforme alle specifiche di Agilent, le protezioni di cui esso è dotato potrebbero essere alterate.

8 Operation and Maintenance Manual

Dutch

WARNING

Iedere handeling binnenin het toestel kan beschadiging veroorzaken. Om iedere mogelijk gevaarlijke shock te vermijden moet de aansluiting met het net verbroken worden, vóór het openen van het toestel.

Voor een continue bescherming tegen brandgevaar, vervang de zekering door een zekering van hetzelfde type en waarde.

Het symbool geeft aan dat de gebruiker de instructies in de handleiding moet raadplegen.

Dit is een produkt van veiligheidsklasse I. Het toestel moet aangesloten worden op het net via een geaard netsnoer. Bij onderbreking van de beschermende geleider, aan de binnenzijde of aan de buitenzijde van het toestel, kan gebruik het toestel gevaarlijk maken. Opzettelijke onderbreking is verboden.

WARNING

Indien het toestel niet gebruikt wordt volgens de richtlijnen van Agilent, gelden de veiligheidsvoorzieningen niet meer.

Operation and Maintenance Manual 9

The following symbols are used on the equipment:

Caution - Refer to manual for operating instructions

Atención - Ver documentación pertinente.

Attention - Consultez les ocuments d'accomagnement.

Vorsicht - Siehe beiliegende Unterlagen.

Pericolo - Vedi documentazione allegata.

Voorzichtig - Raadpleeg di bijehorende documentatie.

Caution - Risk of electrical shock.

Atención - Riesgo de sacudidas eléctricas.

Attention - Risque de choc électrique.

Vorsicht - Risiko eines Elektroschocks.

Pericolo - Pericolo di scosse elettriche.

Voorzichtig - Hoge spanning, levensgevaar.

Caution - Hot surface.

Atención - Superficie caliente.

Attention - Surface brûlante.

Vorsicht - Heisse Oberfläche.

Pericolo - Superficie rovente.

Voorzichtig - Heet oppervlak.

10 Operation and Maintenance Manual

1 Introduction

2 System Description

Specifications 20

Technical Information — 355 SCD 20 Technical Information — 255 NCD 20 Physical Specifications 21

Theory of Operation 23

Sulfur Chemiluminescence Detector 23 Nitrogen Chemiluminescence Detector 23 Dual Plasma Controller 24

Description of Major Components 25

Dual Plasma Burner 25 Figure 1. Cross-Section of the Dual Plasma Burner for the 355 SCD 26 Figure 2. Cross-Section of the Dual Plasma Burner for the 255 NCD 27 Dual Plasma Controller 27 Ozone Generator 28 Chemiluminescence Reaction Cell and Photomultiplier Tube 28 Figure 3. 355 SCD Left Side 29 Figure 4. 355 SCD Right Side 30 Figure 5. 255 NCD Left Side View 31 Figure 6. 255 NCD Right Side View 32 Pressure Transducer 32 Vacuum Pump 32 Chemical Trap 33 Oil Coalescing Filter 33 FID Adapter (Optional) 33 NCD Reaction Cell 33 NCD Photomultiplier Tube and Cooler 34 Figure 7. Schematic for 355 SCD 35 Figure 8. Schematic for 255 NCD, in Nitrogen Mode 36 Figure 9. Schematic for 255 NCD, in Nitrosamine Mode 37

Operation and Maintenance Manual 11

3 Installation

Overview 40

Step 1: Selecting a Location 41

Power Requirements 41 Figure 10. Drawing of the Detector with Dual Plasma Burner and Controller 42 Environmental Considerations 42 Combustion Gas Requirements 42

Step 2: Unpack and Inspect the Instrument 45

Required Installation Tools 45

Step 3: Set Up the Vacuum Pump 46

Installing the Edwards RV5 Pump Oil-Sealed Vacuum Pump 46 Figure 11. RV5 Oil-Sealed Vacuum Pump and Associated Traps (Front Side) 49 Figure 12. RV5 Oil-Sealed Vacuum Pump and Associated Traps (Back Side) 49 Figure 13. RV5 Oil- Sealed Vacuum Pump and Associated Traps (Top) 50 Figure 14. RV-5 Oil-S ealed Vacuum Pump Exhaust Line 51 Installing the Welch Dry Piston Vacuum Pump 52 Figure 15. The Welch Dry Piston Pump 54 Figure 16. Oil Drain Kit with Ballast Control 54

Step 4: Connect the Power Cord 56

Figure 17. SCD Rear Panel Diagram 56

Step 5: Install the Dry Compressed Air or O

Supply 57

Step 6: Install the Signal Output Cables 58

Standard Cable Connection 58 HP 3390 Series Integrator Cable Connection 58 HP 3396 Integrator Cable Connection 58 HP 5890 GC Analog Input Board 58 Agilent 6890 GC Analog Input Board 58

Step 7: Install the Dual Plasma Burner 59

Figure 18. Dimensions of GC Liner Cut-Outs 59

Step 8: Install the Dual Plasma Controller 60

Figure 19. Dual Plasma Controller Rear Panel 60

Step 9: Install Column Connections 61

Capillary Columns 61 Figure 20. Measuring Column Insertion 61

12 Operation and Maintenance Manual

Packed Columns and Columns with an Outside Diameter > 0.8 mm 61

Step 10: Install the Transfer Line 62

4 Front Panel Controls and Initial Startup

Detector Front Panel Controls 64

Figure 21. Front Panel Controls 64 Power Controls 64 Display Output Controls 65 Signal Controls 65 Dual Plasma Controller Controls 66 Figure 22. Dual Plasma Controller Front Panel 66 Initial Startup 67

Detector Interface Setup 69

Initial Checkout 69 Monitoring Oxidizer and Hydrogen Flow with the Dual Plasma Controller 70

5Operation

Start-Up Procedure 72

Detector Operation 73

Detector Stability and Response 73 Column Bleed 73 Coking 73 Hydrogen Poisoning 73 Contaminated Gases 74 Fluctuating Pressures 74

Typical Operating Conditions 75

Table 1. Typical Operating Conditions 75

Detection Limits 76

Table 2. Expected Detection Limits for Chromatographic Conditions 76

Instrument Shut-Down 77

Daily Shutdown 77 Complete Shutdown 77

Special Operating Modes 78

Using the 255 NCD in Nitrosamine Mode 78 Using the SCD in High Sensitivity Mode for Nonhydrocarbon Gaseous Samples 78

Operation and Maintenance Manual 13

6Maintenance

Pump Maintenance 82

Cleaning the Detector 83

Changing the Oil Mist Filter (RV5) 84

Reaction Cell Cleaning 85

Flow Sensor Calibration 88

Detector Sensitivity 89

Assembling the Dual Plasma Burner for Component Replacement with the SCD 90

Table 3. Operating Life of Components for Edwards RV5 Vacuum Pump 82

Figure 23. Reaction Cell, PMT Housing and PMT Socket 86 Figure 24. Reaction Cell 86

Figure 25. Ferrule Placement on Lower Burner Tube 90 Figure 26. Proper Ferrule Orientation to the Large Ceramic Tube 91 Figure 27. Large Ceramic Tube Properly Inserted into the Quartz Heater Assembly 91 Figure 28. Orientation of the Double Taper Ferrule 92 Figure 29. Positioning the Upper Tube in the Union Fitting 92 Figure 30. Tightening the Heater Swivel Nut 93 Figure 31. Proper Alignment of the Burner 93

Assembling the Dual Plasma Burner for Component Replacement with the NCD 95

Figure 32. Ferrule Placement on Lower Burner Tube 95 Figure 33. Proper Ferrule Orientation to the Large Quartz Tube 96 Figure 34. The Quartz Tube Properly Inserted into the Quartz Heater Assembly 96 Figure 35. Burner Assembly Detail 97 Figure 36. Burner Assembly Alignment 97

Tube Replacement for the SCD 98

Figure 37. Orientation of the Double Taper Ferrule 98 Figure 38. Positioning the Upper Tube in the Union Fitting 99 Figure 39. Proper Ferrule Orientation to the Large Ceramic Tube 99 Figure 40. Large Ceramic Tube Properly Inserted into the Quartz Heater Assembly 100 Figure 41. Tightening the Heater Swivel Nut 100 Figure 42. Proper Alignment of the Burner 101

Tube Replacement for the NCD 102

Figure 43. Proper Ferrule Orientation to the Large Quartz Tube 102 Figure 44. Large Quartz Tube Properly Inserted into the Quartz Heater Assembly 103 Figure 45. NCD Tube Replacement Detail 104 Figure 46. NCD Tube Replacement Detail 104

14 Operation and Maintenance Manual

7 Troubleshooting

Solving Detector Problems 106

Power Problems 107

Detector Fuse 107 Vacuum Pump Fuse 107 Dual Plasma Controller Fuses 107 Table 4. Fuses for 100 V, 120 V and 230 V Versions of 355 SCD and 255 NCD 108 Figure 47. Fuse Positions on the Power Supply Board 108

Ozone Generation Problems 109

Ozone Generator 109 High Voltage Transformer 109 Plugged Restrictor Lines 110

Response Problems 111

Temperature Reading Problems 112

Diagnosing General Problems 113

Table 5. Troubleshooting Detector Issues 113 Table 6. Troubleshooting Pump Issues 115 Table 7. Troubleshooting Burner Issues 116

Index

Operation and Maintenance Manual 15

16 Operation and Maintenance Manual

Agilent 355 Sulfur and 255 Nitrogen Chemiluminescence Detectors Operation and Maintenance Manual

1 Introduction

This manual will guide you in the installation, operation, and troubleshooting of the Agilent 355 Sulfur Chemiluminescence Detector (SCD) and the Agilent 255 Nitrogen Chemiluminescence Detector (NCD). This manual is intended for use with the Agilent 355 SCD or 255 NCD with the Dual Plasma Burner and Controller.

This operation and service manual has some important conventions, such as the use of boxed warnings. This information is deliberately set out from the text for emphasis and should be followed to assure operator safety and proper instrumental operation.

If you are installing the 355 SCD or 255 NCD yourself, follow the installation procedures described in the following sections. If your instrument is already installed, turn to the Operation section to begin.

Agilent Technologies

18 Operation and Maintenance Manual

Agilent 355 Sulfur and 255 Nitrogen Chemiluminescence Detectors Operation and Maintenance Manual

2 System Description

Specifications 20

Theory of Operation 23 Description of Major Components 25

Agilent Technologies

Specifications

Technical Information — 355 SCD

Sensitivity

Typical Selectivity g S/g C > 2 x 10

Linearity >10

Precision and Stability

†

Typical < 0.5 pg S/second (signal to noise 3.3:1)

<2% RSD 2 hours

<5% RSD 72 hours

Ozone flow through the Post Ozone Restrictor 20-30 mL/min at 3-6 psig

Typical reaction cell pressure 4 - 8 Torr RV5 Oil Sealed Pump

6 - 12 Torr Dry Piston Pump

Typical Burner Pressure 250-400 Torr operating

Typical Burner Temperature 800 °C

Typical Air Flow Rate 65 SCCM recommended

3-10 SCCM recommended with FID adapter

Typical Hydrogen Flow Rate 40 SCCM recommended

Signal Output Ranges 0-1V, 0-10V

Typical time to reach 800 °C from room

10 min typical(120 VAC, 60 Hz)

temperature

Typical safety shroud outside temperature <65 °C at 800 °C Burner temperature typical

Recorder output 0-1 V or 0-10 V

* Burner temperature 800 °C, 80 SCCM air, and 60 SCCM hyrdrogen, test compound dimethyl sulfide in toluene.

† Based on thiopene in benzene at 1 ppm mass sulfur, 1 µL injection split 1:10, 30 m, 0.32 mm ID, 1 µm thick CP

wax (n=10 for 2.5 hours; n=42 for 72 hours).

Subject to change without notice.

Technical Information — 255 NCD

Sensitivity <3 pg N/second (signal to noise 3:1) in both N

and nitrosamine modes

Selectivity g N/g C > 2 to 10

nitrosamine mode is matrix-dependent)

Linearity >10

20 Operation and Maintenance Manual

in N mode (selectivity in

Repeatability

Gas flow through Ozone Generator 20-30 mL/min at 3-6 psig (inlet pressure)

Typical reaction cell pressure 4 - 8 Torr RV5 Oil Sealed Pump

Typical Burner Pressure 130 - 150 torr operating

Typical Burner Temperature 900 °C

Typical Hydrogen Flow Rate 6-10 SCCM

Typical Oxygen Flow Rate 8 - 15 SCCM

Signal Output Ranges 0-1V, 0-10V, 0 - 10V

* Burner temperature 950 °C, 11 SCCM oxygen, and 6 SCCM hydrogen; 25 ppm N as nitrobenzene in toluene;

0.2 µL injection on column (HP 19095-121Z), n=7 for 3 hours; n=13 for 18 hours and n=10 n-dipropylnitrosamine in toluene at 4 µg/mL, 0.2 µL injection on column (HP 19095-121Z).

Physical Specifications

<1.5% RSD 8 hours (~ the same in N and nitrosamine)

<2% RSD 18 hours (~3% RSD in nitrosamine mode over 21 hours)

6 - 12 Torr Dry Piston Pump

Power requirements

355 SCD Detector 115 VAC, 50/60 Hz, 1400 W

100 VAC, 50/60 Hz, 1400 W 220-240 VAC, 50/60 Hz, 650W

255 NCD Detector 115 VAC, 50/60 Hz, 1400 W

100 VAC, 50/60 Hz, 1400 W 220-240 VAC, 50/60 Hz, 650W

Dual Plasma Controller 100-120 VAC, 50/60 Hz, 200 W

220-240 VAC, 50/60 Hz, 200 W

Dimensions and weight

Detector Height: 16.0 in (40.6 cm)

Width: 9.2 in (23.4 cm) Depth: 21.8 in (55.3 cm) 355 SCD Weight: 34.0 lbs (15.0 kg) 255 NCD Weight: 37.5 lbs (17.0 kg)

Operation and Maintenance Manual 21

Dual Plasma Controller Height: 5.0 in (12.7 cm)

Width: 9.5 in (24.1 cm) Depth: 12.5 in (31.8 cm) Weight: 9.9 lbs (4.5 kg)

Dual Plasma Burner Height: 12.3 in (31.2 cm)

Diameter: 4.0 in (10.2 cm) Weight: 1.9 lbs (0.9 kg)

Oil Sealed Vacuum Pump (RV5) Height: 10.3 in (26.1 cm)

Width: 6.0 in (15.2 cm) Depth: 16.9 in (43.0 cm) Weight: 47.3 lbs (21.5 kg)

Oil Free Dry Piston Pump Height: 12.0 in (30 cm)

Width: 9.0 in (22.9 cm) Depth: 14.0 in (35.6 cm) Weight: 29.9 lbs (13.6 kg)

Installation Category II

Pollution Degree 2

Ambient Temperature 50 - 104 °F (10-40 °C)

Relative Humidity Up to 95%, noncondensing

Normal Operating Environment Intended for indoor use only

Maximum Altitude 2,000 m (6,562 ft)

Mains Supply Voltage Fluctuation not to exceed 10% of nominal

voltage

22 Operation and Maintenance Manual

Theory of Operation

Sulfur Chemiluminescence Detector

The Agilent model 355 Sulfur Chemiluminescence Detector (SCD) is a sulfur-selective detector for gas chromatography. Operation of the SCD is based on the chemiluminescence (light-producing reaction) from the reaction of ozone with sulfur monoxide (SO) produced from combustion of the analyte:

Sulfur compound (analyte)

SO + O

→ SO2 + O2 + hη (<300–400 nm)

→ SO + H

A vacuum pump pulls the combustion products into a reaction cell at low pressure, where excess ozone is added. Light produced from the subsequent reaction is optically filtered and detected with a blue-sensitive photomultiplier tube and the signal is amplified for display or output to a data system. Figure 1 is a pneumatic flow diagram that illustrates how the components of the system are integrated.

The Detector has an enclosed, dedicated (Dual Plasma) Burner designed to enhance production of the SO intermediate. This Dual Plasma Burner mounts in the detector port of the GC. A Dual Plasma Controller provides temperature control and gas-flow regulation to operate the Dual Plasma Burner.

The Agilent model 355 SCD provides high sensitivity (<0.5 pg S/sec), with linear and equimolar response over four orders of magnitude (per Sulfur atom) while maintaining high selectivity over common solvents. The Agilent SCD is compatible with most commercially available gas chromatographs.

Nitrogen Chemiluminescence Detector

Operation of the Agilent model 255 Nitrogen Chemiluminescence Detector is based on the chemiluminescence or light-producing reaction of ozone with nitric oxide formed from combustion. Reacting nitric oxide with ozone results in the formation of electronically excited nitrogen dioxide. The excited nitrogen dioxide emits light, a chemiluminescence reaction, in the red and infrared region of the spectrum. The light emitted is directly proportionally to the amount of nitrogen in the sample,

O + other products

NO + O

NO2 NO2 + hη (>800 nm)

The light (hη) emitted by the chemical reaction is optically filtered and detected by a photomultiplier tube. The signal from the photomultiplier tube is amplified for display or output to a data system. Organic compounds containing nitrogen react to form nitric oxide, carbon dioxide, and water.

2/O2

--------------

R-N + O

Operation and Maintenance Manual 23

→ NO + CO

+ H2O

Dual Plasma Controller

The Dual Plasma Controller provides all operational parameters of the Dual Plasma Burner except for the Detector base temperature. The Detector base temperature is controlled by circuitry in the GC. Parameters monitored or regulated by the Controller include Burner temperature, Burner temperature set-point, hydrogen and oxidant flow rates, and Burner pressure. The temperature set-point, actual pressure, oxidant and hydrogen flow rates are displayed by rotation of a 4-position switch. Power, valve operation, temperature within set-point range and fault conditions are indicated with LED illumination on the front display panel.

The Dual Plasma Controller incorporates several safety features. The safety circuitry detects faults such as power loss, vacuum loss, thermocouple failure, heater element failure, broken ceramic tube, or high temperature. When a fault is detected, the Fault LED illuminates and hydrogen and oxidant flow is stopped by normally-closed solenoid valves.

Dual Plasma Burner with the 355 SCD

The Dual Plasma Burner is based on the same chemistry and basic principles of earlier SCD Burner designs. A key difference, however, is the addition of a second “flame” or “plasma,” the lower is oxygen-rich and the upper is hydrogen-rich. The Burner consists of a tower assembly that contains an outer sheath for burn protection, a heating element, thermocouple, and combustion tubes. Conversion of sulfur containing compounds to SO occurs within the ceramic reaction chamber housed in the Burner assembly. Agilent also provides a Flame Ionization Detector (FID) option for the simultaneous collection of hydrocarbon and sulfur chromatograms for some GCs.

Dual Plasma Burner with the 255 NCD

Compounds eluted from the GC column are combusted in the Dual Plasma Burner first by an oxygen rich flame (plasma) followed by catalytic combustion on a Noble metal screen. For hydrocarbons, this two stage combustion technique results in complete conversion of the matrix to products, such as carbon dioxide and water, which do not chemiluminesce with ozone. Nitrogen atoms in a compound are converted into nitric oxide and potentially other nitrogen oxide species. In the second stage, the catalyst is used to convert other nitrogen oxide species to nitric oxide, resulting in a high efficiency of conversion.

24 Operation and Maintenance Manual

Description of Major Components

Dual Plasma Burner

The Dual Plasma Burner consists of a tower assembly that contains an outer sheath for burn protection, a heating element, thermocouple, and combustion tubes. In the SCD, conversion of sulfur containing compounds to SO occurs within the ceramic reaction chamber housed in the Burner assembly and potentially interfering hydrocarbons are oxidized to CO

the oxidant. In the NCD, oxygen is used as the oxidant.

A fitting is located on top of the Burner. The vacuum line from the Detector box is connected directly to the top of this fitting and H2 is input to the longer side of this fitting. The air inlet is connected to the base of the Burner.

The Burner is mounted onto the GC by a model-specific mounting kit (see www.Agilent.com/chem or contact Agilent for the most current information). The GC column is inserted into the Burner using a 1/32" knurled nut and fused silica adapter ferrule.

A cross-section illustration of the Dual Plasma Burner for the 355 SCD is shown in Figure 1 and for the 255 NCD is shown in Figure 2.

and H2O, with air as

Operation and Maintenance Manual 25

Figure 1 Cross-Section of the Dual Plasma Burner for the 355 SCD

26 Operation and Maintenance Manual

Figure 2 Cross-Section of the Dual Plasma Burner for the 255 NCD

Dual Plasma Controller

The Dual Plasma Controller powers the Dual Plasma Burner and supplies its gases. Hydrogen and oxidant should be provided at 25 psig (1.72 bar) and the Controller is plugged into an appropriate AC electrical outlet.

WARNING

Operation and Maintenance Manual 27

Exceeding the gas inlet pressure of 25 psig (1.72 bar) may damage the hydrogen and oxidant sensors or burst their connective tubing.

The parameters monitored or regulated by the Controller include Burner

temperature, hydrogen and oxidant f low rates, and Burner pressure. The temperature, actual pressure, oxidant and hydrogen flow rates are selected for display by rotation of a 4-position control knob. Power, valve operation, temperature within set-point range and fault conditions are indicated with LED illumination on the front display panel.

Ozone Generator

The SCD and NCD produce ozone by corona discharge using a clean, pressurized air or oxygen source. Use of oxygen should increase ozone production and, hence, Detector response. High voltage to the ozone generator is applied only when the reaction cell pressure is less than 100 torr in the SCD and less than 200 torr in the NCD. Gas flow through the ozone generator is controlled by a pressure regulator and flow restrictors.

WARNING

Ozone is a hazardous gas and a strong oxidant. Exposure to ozone should be minimized by using the instrument in a well ventilated area, changing the chemical trap regularly, and venting the exhaust of the vacuum pump. The ozone generator should be turned off when the instrument is not in use to reduce maintenance requirements.

Chemiluminescence Reaction Cell and Photomultiplier Tube

Sulfur monoxide (formed in the Burner) and ozone (produced in the ozone generator located in the Detector) are mixed in the reaction cell. The cell is designed such that the reaction between SO and O

the photomultiplier tube (PMT). A UV band pass filter (300 - 400 nm) located between the reaction cell and the PMT selectively transmits the light emitted by the SO/O

the UV band pass filter eliminates interference from non-sulfur containing analytes (e.g. nitric oxide, olefins, etc.) which also undergo chemiluminescent reactions with ozone. A background signal is typically present as a result of ozone-wall interactions and low level sulfur contamination of Detector gases. This background signal can be used as a troubleshooting aid (see Section 10).

reaction. Efficient combustion in the ceramic tubes coupled with

occurs directly in front of

28 Operation and Maintenance Manual

7 9

1. Ozone Generator

2. High Voltage Transformer

3. Photomultiplier Tube Socket

4. Photomultiplier Housing

5. Reaction Cell

Figure 3 355 SCD Left Side

6. Vacuum Line

7. Particulate Filter

8. Pre-Ozone Restrictor

9. Post-Ozone Restrictor

10. Pressure Transducer

Operation and Maintenance Manual 29

P4 P5

WHT LOAD NEUT

P2 P3

TP3

TP8

RV1

TP9 TP11

TP8 TP10 TP3

TP12

AMP 1 I

ALCO

11 12 15

ELECTRONICS

OZONE

PUMP

TP4

TP5 TP1

TP2

TP12

HV/100

TP11

TP13

GND

TP14

TP9 TP10

TP15 TP6

TP7 TP16

LOAD NEUT

PUMP

OUT

P6 P7

OZONE

GEN

WHT

LINE NEUT

WHT

IN OFST

OUT OFST

RV1

RV2

TP2

TP7 TP6 TP4 TP 5

TP13

OUT

TO FRONT

TP1

PANEL

SIEVERS RESEARCH

USA

Figure 4 355 SCD Right Side

11. Amplifier Cable

12. HV Cable

13. PMT Amplifier

14. EMI Filter

15. Fuses

16. Pressure Regulator

17. Transfer line

18. Front panel display

30 Operation and Maintenance Manual

+ 88 hidden pages

Agilent Technologies G6600-90006 User Manual

Contents

Specifications

Physical Specifications

Theory of Operation

Sulfur Chemiluminescence Detector

Nitrogen Chemiluminescence Detector

Dual Plasma Controller

Description of Major Components

Dual Plasma Burner

Dual Plasma Controller

Ozone Generator

Chemiluminescence Reaction Cell and Photomultiplier Tube