|
time monitoring of the GC when it is connected with Lab Monitor & Diagnostic Software, even when also connected to a data system.
• One-button access to maintenance and service modes from the keyboard
• Preprogrammed leak tests
• Automatic Liquid Sampling is fully integrated into mainframe control.
• Set point and automation control can be done from the local keyboard or via a networked data system. Clock-time programming can be initiated from the front
panel to initiate events (on/off, method start, etc.) at a future date and time.
• A run time deviation log is created for each analysis to ensure that all method parameters were achieved and maintained.
• A full array of traditional gas sampling and column switching valves are available
• 550 timed events
• Display of all GC and ALS set points at the GC or data system.
• Context-sensitive online help Column Oven
• Dimensions: 28 × 31 × 16 cm. Accommodates up to two 105 m × 0.530 mm id capillary columns or two 10-ft glass packed columns (9 in. coil diameter, 1/4 in. od),
or two 20-ft stainless steel packed columns (1/8 in. od).
• Operating temperature range suitable for all columns and chromatographic separations.
Ambient temperature +4 °C to 450 °C.
- With LN2 cryogenic cooling: –80 to 450 °C.
- With CO2 cryogenic cooling: –40 to 450 °C.
• Temperature set point resolution: 1 °C.
• Supports 20 oven ramps with 21 plateaus. Negative ramps are allowed.
• Maximum achievable temperature ramp rate: 120 °C/min (120 V units are limited to 75 °C/min, see Table 1).
• Maximum run time: 999.99 min (16.7 h).
• Oven cool down (22 °C ambient) 450 to 50 °C in 4.0 min (3.5 min with oven insert accessory).
• Ambient rejection: < 0.01 °C per 1 °C.
Electronic Pneumatics Control (EPC)
• Compensation for barometric pressure and ambient temperature changes is standard.
• Pressure set points may be adjusted by increments of 0.001 psi, with typical control ± 0.001 for the range 0.000 to 99.999 psi; 0.01 psi for the range 100.00 psi to 150.00 psi
• User may select pressure units as psi, kPa, or bar.
• Pressure/flow ramps: Three maximum.
• Carrier and makeup gas settings selectable for He, H2, N2, and argon/methane.
• Flow or pressure setpoints for each inlet or detector parameter with both Agilent 7890A and Agilent ChemStations.
• Constant flow mode is available when capillary column dimensions are entered into the 7890A.
• Split/splitless, and PTV inlets have flow sensors for the control of split ratio.
• Inlet modules Pressure sensors: Accuracy: <± 2% full scale, Repeatability: <± 0.05 psi, Temperature coefficient : <± 0.01 psi/°C, Drift: <± 0.1 psi/6 months.
• Flow sensors: Accuracy: <± 5% depending on carrier gas, Repeatability: <± 0.35% of setpoint, normalized temperature and pressure (NTP)* per °C for He or H2; <± 0.05 mL/min NTP per °C for N2 or Ar/CH4.
• Detector modules: Accuracy: <± 3 mL/min NTP or 7% of setpoint, Repeatability:
<± 0.35% of setpoint *NTP = 25 °C and 1 atmosphere
Inlets
• Maximum of two inlets installed
• EPC compensated for atmospheric pressure and temperature variation
• Inlets available:
- Packed purged injection port (PPIP)
- Split/splitless capillary inlet (S/SL)
- Temperature-programmable cool on-column (PCOC)
- Programmable temperature vaporizer (PTV)
- Volatiles inlet (VI)
S/SL
• Suitable for all capillary columns (50 μm to 530 μm id).
• Split ratios up to 7,500:1 to avoid column overload.
• Splitless mode for trace analysis. Pressure-pulsed splitless is easily accessible for best performance.
• Maximum temperature: 400 °C.
• EPC available in two pressure ranges: 0 to 100 psig (0 to 680 kPa) for best control for columns £ 0.200 mm diameter; 0 to 150 psig for columns < 0.200 mm diameter.
• Gas saver mode to reduce gas consumption without compromising performance.
• Electronic septum purge flow control to eliminate “ghost” peaks.
• Total flow setting range: 0 to 200 mL/min N2 0 to 1,250 mL/min H2 or He
• Turn top inlet sealing system is built in standard with each 7890A S/SL inlet for quick, easy, injector liner changes
PCOC
• Direct injection onto cool capillary column ensures quantitative sample transfer with no thermal degradation.
• Automatic liquid injection supported directly onto columns ≥ 0.250 mm id.
• Maximum temperature: 450 °C. Temperature programming in 3 ramps or tracking oven. Subambient control to –40 °C is optional.
• Electronic pressure control range: 0 to 100 psig.
• Electronic septum purge flow control.
• Optional solvent vapor exit for large-volume injections.
- Electronically controlled, inert, three-way valve allows solvent venting.
- Includes software for method optimization.
- Preassembled retention gaps/vent line/analytical column for easy installation.
PPIP
• Direct injection onto packed and wide-bore capillary columns.
• Electronic flow/pressure control: 0 to 100 psig pressure range, 0.0 to 200.0 mL/min flow range. Ranges are chosen to provide optimum performance over
normal packed column set point ranges.
• Electronic septum purge flow control.
• 400 °C maximum operating temperature.
• Adapters included for 1/4-in. and 1/8-in. packed columns, and 0.530-mm capillary columns.
PTV
• Most versatile inlet for difficult samples supporting cool injections and large volume injections in split and splitless modes.
• Temperature control: either LN2 (to –160 °C) or LCO2 (to –65 °C) cooling. Temperature programming of up to 3 ramps at up to 720 °C/min. Maximum temperature: 450 °C.
• EPC pressure range 0 to 100 psig.
• Split ratio up to 7,500:1.
• Electronic septum purge flow control.
• Choice of Gerstel septumless head or Merlin Microseal® septum head.
• 450 °C maximum operating temperature.
• Total flow setting range:
- 0 to 200 mL/min N2
- 0 to 1,250 mL/min H2 or He
VI
• Very low volume (32 μL) interface suitable for gas or prevaporized samples. Recommended for use with headspace, purge and trap, or thermal desorption samplers.
• Three modes for optimized sample introduction: split (up to 100:1 split ratio), splitless, and direct.
• Optimized EPC (H2 or He carrier, 0.00 to 100 psig pressure control, 0.0 to 100 mL/min flow control).
• Electronic septum purge flow control.
• Silcosteel® treated flow path provides inert surface for minimum component adsorption.
• Maximum temperature: 400 °C.
Detectors
• Electronic pneumatics control and electronic on/off for all detector gases.
• EPC compensated for atmospheric pressure and temperature variation
Detectors available:
FID
• Flame ionization detector (FID) that responds to most organic compounds.
• Minimum detectable level (for tridecane): < 1.8 pg C/s
• Linear dynamic range: >107 (± 10%). Full-range digital data path enables peaks to be quantified over the entire 107 concentration range in a single run.
• Data rates up to 500 Hz accommodate peaks as narrow as 10 msec at half height.
• Standard electronic pneumatic control for three gases:
- Air: 0 to 800 mL/min
- H2 : 0 to 100 mL/min
- Makeup gas (N2 or He): 0 to 100 mL/min
• Available in two versions: capillary column optimized or adaptable for either packed or capillary columns.
• Flameout detection and automatic reignition
• 450 °C maximum operating temperature
TCD
• Thermal conductivity detector (TCD), a universal detector that responds to all compounds, excluding the carrier gas.
• Minimum detectable level: 400 pg tridecane/mL with He carrier. (This value may be affected by laboratory environment).
• Linear dynamic range: > 105 ± 5%
• Unique fluidic switching design provides rapid stabilization from turn-on, low-drift performance.
• Signal polarity can be run-programmed for components having higher thermal conductivity than the carrier gas.
• Maximum temperature: 400 °C
• Standard EPC for 2 gases (He, H2, Ar, or N2 matched to carrier gas type)
• Make-up gas: 0 to 12 mL/min
• Reference gas: 0 to 100 mL/min
• The 7890A GC can accommodate a third detector as TCD located on the left-hand side of the GC.
Micro-ECD
• Micro-electron capture detector (micro-ECD), a very sensitive detector for electrophilic compounds such as halogenated organic compounds.
• Minimum detectable level: < 6 fg/mL lindane
• Proprietary signal linearization. Linear dynamic range: > 5 × 104 with lindane
• Data acquisition rate: up to 50 Hz
• Uses ß emission of < 15 mCi 63Ni as the electron source.
• Unique micro-cell design minimizes contamination and optimizes sensitivity
• 400 °C maximum operating temperature
• Standard EPC makeup gas types: argon/5% methane or nitrogen; 0 to 150 mL/min
NPD
• Nitrogen-phosphorus detector (NPD), a detector specific to nitrogen or phosphoruscontaining compounds.
• MDL: < 0.4 pg N/s, < 0.2 pg P/s with azobenzene/malathion/ octadecane mixture
• Dynamic range: > 105 N, > 105 P with azobenzene/malathion mixture
• Selectivity: 25,000 to 1 g N/g C, 75,000 to 1 g P/g C with azobenzene/
malathion/octadecane mixture
• Data acquisition rate: up to 200 Hz
• Standard EPC for three gases:
- Air: 0 to 200 mL/min
- H2: 0 to 30 mL/min
- Makeup gas: 0 to 100 mL/min
• Available for packed/capillary columns or optimized for capillary columns
• 400 °C maximum operating temperature
FPD
• Single-wavelength flame photometric detector (FPD), or dualwavelength
flame photometric detector (DFPD)+a sensitive, specific detector to sulfur- or
phosphorus-containing compounds.
• MDL: < 60 fg P/s, < 3.6 pg S/s with methylparathion
• Dynamic range: > 103 S, 104 P with methylparathion
• Selectivity: 106 g S/g C, 106 g P/g C
• Data acquisition rate: up to 200 Hz
• Standard EPC for three gases:
- Air: 0 to 200 mL/min
- H2: 0 to 250 mL/min
- Makeup gas: 0 to 130 mL/min
• Available in single- or dualwavelength versions.
• 250 °C maximum operating temperature
• Agilent 7890A GC’s ability to handle 4 signals allow simultaneous use of DFPD, top-mounted GC detector, and TCD.
SCD (Model 355)
• Highest sensitivity and selectivity for sulfur-containing compounds.
• MDL: Typical < 0.5 pg/s, dimethyl sulfide in toluene
• Linear dynamic range: > 104
• Selectivity: > 2 x 107 g S/g C NCD (Model 255)
• High selectivity for nitrogencontaining compounds.
• MDL: < 3 pg N/s, in both N and nitrosamine modes, 25 ppm N as nitrobenzene in toluene
• Linear dynamic range: >104
• Selectivity: > 2 x 107 g N/g C (selectivity in nitrosamine mode is matrix pendent)
See Agilent Sulfur Chemiluminescence Detector and Nitrogen Chemiluminescence Detector Specification Guide for additional information regarding performance and physical and environmental specifications.
MSD
See 5975 Series MSD specifications. Specialized detectors are available through Agilent Channel Partners including: atomic emission, helium ionization, and pulsed discharge ionization. Auxiliary EPC Devices The 7890A GC has two positions for
auxilary EPC devices located on the back of the GC. Each position can be any combination of auxiliary EPC or pneumatics control module. Note: The communication for a third detector as TCD EPC module (located on the left side of the GC) interfaces via one of these auxiliary EPC module positions. If a third detector (TCD) is installed, one of these auxiliary positions is thus taken.
Auxiliary EPC Module
• Three channels of pressure control
• EPC compensated for atmospheric pressure and temperature variation when connected to a user-defined capillary column
• Psig (gauge) and psia (absolute) pressure control
• Forward pressure regulated
• Maximum of 2 auxiliary EPC modules per GC Pneumatics Control Module (PCM)
• 2 channels for operation
• EPC compensated for atmospheric pressure and temperature variation when connected to a user-defined capillary column
• First channel:
- Pressure or flow control
- Psig (gauge) and psia (absolute) pressure control
- Forward pressure regulated
• Second channel:
- Pressure control
- Psig (gauge) and psia (absolute) pressure control
- Forward pressure or back pressure regulated
• PCM can be located in either/ both inlet EPC positions, and in either/both uxiliary positions on the back of the 7890A GC
• Maximum of 3 PCMs per GC Capillary Flow Technology Agilent’s proprietary Capillary Flow Technology provides devices with reliable, leak-free, in-oven apillary
connections to help analyze complex samples and provide gains in productivity.
Devices feature:
• Photolithographic chemical milling for low dead volume flow pathways
• Diffusion bonding to form a single flow plate
• “Credit card” profile for fast thermal response
• Projection welded connections for leak-tight fittings
• Deactivation of all internal surfaces in the sample path for inertness
All of the following purged Capillary Flow devices require one channel from an auxiliary EPC or PCM module.
Deans Switch
Deans switching provides additional selectivity using 2-dimensional GC analysis. Peaks of interest that may be coeluting on one column are diverted to a separate column of different stationary phase. This technique can also reduce maintenance
costs by having troublesome solvents or other components bypass detectors or columns.
• Dimensions: 65 mm x 31 mm x 1 mm (65 mm x 31 mm x 11 mm, including weldment connectors with tubing to reach through top of oven.)
• Weight: 30 grams, not including connector tubing. Purged Effluent Splitters
A 3-way purged effluent splitter sends column effluent to three detectors, even an MSD. More information can be obtained in a single run to help locate target peaks in unknowns. A 2-way purged effluent splitter version is also available.
• Dimensions: 65 mm x 31 mm x 1 mm (65 mm x 31 mm x 11 mm, including weldment connectors with tubing to reach through top of oven.)
• Weight: 26 grams, not including connector tubing.
QuickSwap
The QuickSwap device, for GC/MS, allows you to change a column or perform inlet maintenance without venting the MSD, saving a considerable amount of downtime.
• Dimensions:
31 mm x 16 mm x 1 mm (31 mm x 16 mm x 22 mm, including weldment connectors)
• Weight: 10 grams, not including connector tubing.
Backflush
Each of the above purged Capillary Flow devices also provides the ability to backflush. By reversing column flow immediately after the last compound of interest has eluted, you can eliminate long bakeout times for highly retained (or
high-boiling) contaminants, thereby shortening cycle times and protecting the column and detector. As backflush occurs after peaks of interest have eluted, the chromatographic method for peaks of interest does not need to change. Backflush
is available when the column is attached to a split/splitless, volatiles interface, or PTV inlet.
The 7890A GC firmware has been optimized for backflush operation:
• Displays positive and negative flows
• Inlet/outlet pressures settable to the limits of the controlling EPC devices.
• EPC can be introduced at any column or restrictor connection
• Capillary Flow configuration of up to six columns/restrictors Agilent GC Multitechnique ChemStation, EZChrom Elite data system, and GC/MSD ChemStation now include user-interface screens to simplify backflush set-up and
operation with the 7890A GC.
ALS Interface Module
• 7683 ALS Interface standard. Provides power and communications for up to two 7683 automatic injectors, one automatic sampler tray, and one bar code reader.
• Injector and tray install easily without the need for alignment. |
