Firma:              Fisons

Modell:            8000

Kommentar:   Dokumente engl.

8000 Series Gas Chromatographs

The 8000 Series forms a complete range of high performance instrumentation, designed to meet the needs set by the current and fut-Lire Jemands of the world of chromatography. The 8000 Series has been developed to take advantage of themost recent developments in Instrument construction, and Indodes more integrated electronics, improved injector design and more comprehensive diagnostics. A comprehensive test and calibration package is available to enable the engineer to service the chromatograph from a PC in the customer’s   own laboratory. Modular design means your chromatograph's capabilities can be easily expanded at any time in the future. The 8000 Series continues the Fisons Instruments tradition of providing the Analystwith innovative and reliable instrumentation at the highest level of analytical excellence.

The chromatographs in the 8000 Series may be configured for both packed and capillary gas chromatography and may take advantage of a complete range of sampling Systems and detector units. How your chromatograph is configured will depend an the model you haue Chosen. Tables 1.1 a and 1.1 b Show the base unit configuration currently available in the 8000 Series.

All the configurations contain HYDROGEN and AIR lines suitable for the flame based detectors; FID, NPD, FPD. When operating wich ECD, a MAKE-UP GAS can be supplied along the hydrogen line.

NPD/FPD detectors, more particularly for capillary applications, ons, may require a dedicated MAKE-UP line, fitted as standard to 8160, 8340 and 8380 instrument models. Otherwise, additional lines for MAKE-UP and AIR may be optionally purchased respectively under part no. 190 04602 and 190 04609.

The AUX line in table 1.1 a refers to a factory fitted auxiliary line installed into the top of the oven. The standard base unit configurations, however, do not include connections within the pneumatics section.

To introduce the constittient parts of the base unit we will follow the chromatographic sequence through the instrument: pneumatics, injection system, oven, control unit, detectors and data processing. *

INJECTION SYSTEMS

The following injection Systems are available within. the 8000 Series GCs. Depending an the base unit configuration of your particular instrument, the chromatograph will be delivered with the appropriate injector units installed.

PACKED COLUMN INTJECTOR

The Standard FISONS Instruments injection port J70 (Fig. 1.11) for packed column instruments is designed for both vaporisation and direct on-column Sample injections. lt may acceptglass columns with an outside diameter of 4 (3 mm I.D.) to 6 mm (4 mm LD.) or metal columns with an outside diameter of 4 mm (2 mm I.D.) using an appropriate metal adaptor. If desired, a glass liner may be installed for Lise with 6 mm 0.D columns.

Figl.11. Schematic diagram of the packed column injector.

The sample is injected through a special silicone septum held in place by a septum cap. Special septum coolers are available an request to minimise septum bleed at higher temperatures, eliminating ghost peaks in the chromatogram. A septum purge may be additionally fitted to the injector (partno. 402 01800) and low bleed Septa 77 (P/N313.03209) are also available for the J70 packed column injector.

The injector unit is heated by a pair of 70 W cartridge heaters housed in an aluminium block. The temperature is regulated by the relevant temperature Controller in the Control Unit and monitored by a platinum wire Sensor in contact with the heating block. The temperature range of the injection block is 10 - 20 °C above anibient to 450 °C, adjustable in increments of 1 °C.

The packed column injector may also be modified to accept wide bore capillary columns.

VAPORISINGSPLIT-SPLITLESSINJECTOR

The 8000 Series Gas Chromatographs feature a redesigned split/splitless injector unit for

capillary gas chromato raphy (SSL 71, fig 1.12). Its development has been based an the 9

intensive research in the field of the injections with capillary, col-Linins, particularly with regard to splitless injection technique. The design of the in)*ectionport features a new flexible geometry which may be easily optimised for either Split or splitless applications (See paragraph 3.1.2) and ensures superior performances in terms of transfer of the Sample to the column ininimising heavy components discrimination.

Fig 1.12. Schematic representation of the SSL 71 split/splitless injector.

For both split and splitless applications the sample solution is injected into a glass-lined h

vaporisation chamber through a septum. The injection technique used however will determine the choice of glass liner and length of syringe needle employed (See paragraph 3.4.3).

Sample Splitting and septum flushing are accomplished by two high precision micrometric needle valves. They are located mithin the heated area of the injector preventing any condensation of sample components and subsequent sample contamination.

These valves may be manually operated (part no. 1-90 04590) for split in)* ections but may be operated automatically for splitless applications (part no. 190 04750).

Packed columns may also be installed into the SSL 71 capillary split/splitless injector using the necessary adaptor kit (part no. 190 04637).

Heating is supplied by m   80W cartridge heaters housed in an aluminium block.

The temperature is regulated bytlie relevant temperature controller in the Control Unit and monitored by a platinuni wire Sensor.

CAPILLARY COLD ON-COLUMN INJECTOR

Substantially developed from Grob's original design, the Tatest Fisons Instruments on­column injector unit (OC-V 71) is shown schematically in fig 1.13.

Fig 1.13. Capillary cold on-column injector.

The injection block is kept at ambient temperature by the primary cooling system which maintains a flow of cooling air from the rear of the Instrument directed onto the injector body. The sample is introduced directly onto the top of the capillary column using a 75 mm metal or fused silica syringe needle. The restriction located in the butterfly valve allows the syringe to enter the column while maintaining the carrier gas pressure at the head of the column. The unique secondary cooling system ensures complete sample transfer from the syringe to the capillary column and is also effective for reducing peak distortion caused by undesired phenomena.

The standard upper section of the on-column injector has an internal diameter of 0.3 mm for metal syringe seedles of 0.2 3 mm OD. An optional upper block of 0.2 mm ID is available for a fLised silica seedle of 0.17 mm OD (part no. 299 02075).

The current on-column injector has been designed to allow the following kit modifications to be easily made (fug 1.14):

-            Fully automatic valve Operation for manual injection (part no. 190 04620)

-            Direct on-column injection via a septum (OC-S 75; part no. 190 04595)

-            Injections using the AS 800 Autosimpler (OCV 80; P/INT 190 04649)

The use of an autosimpler necessarily requires the use of wide bore capillar-,- columns or at least of a wide bore pre-column.

Fig.1.14. Adaptor kits for capillai-v cold on-column injection.

H.O.T. COLD ON-COLUMN INJECTOR

High oven temperature cold on-column injection is possible with the 8000 Serien Gas Chromatographs. This technique is not available with the standard cold on-column injector bat is workable with some modifications to the standard injector. Two patented modifications are available for the standard capillary on-column injector:

- The firnt involves extending the secondarycooling system of the OC injector using a metal cooling jacket around the top 15 cin of the column .

- The second solution allows more complete control of the injection temperature by using the MFA 815 control unit.

The main advantages of the HOT cold on-column injection technique are:

-            Short analysis time

-            Short residence time for coinponents affected by column activity

-            Allows isothermal analysis of high boiling components

-            Reduces effects of column bleed and carrier gas impurities The technique, however, is limited to small sample size: 1 µl or less.

COLD SPLIT-SPLITLESS INJECTOR

The cold split-splitless injector is a patented invention of Fisons Instruments designed to extend the advantages of cold on-column injection to a wider range of sample typen. The injector includes a programmable temperature vaporising (P'1'~ unit and the MFA 815 Controller combined with the standard capillary on-column injector. The fall range of injection modes possible with this arrangement includes:

Cold on-column with secondary cooling

HOT (High Oven Teinperature) cold on-column with extended secondary cooling

PTV (Programmahle Temperature of Vaporization)

PTV total transfer

PTV with solvent elimination (Split and/or back fluste)

Sample enrichment by cryotrapping

Septumless hot split-splitless

The modified injector may be fully automated including the use of the AS 800 autosampler.

COLUMN OVEN

The 8000 Series Gas Chromatograph includes as standard a column oven with a high degree of thermal stability. Oven performance has been optimised by a unique patented solution in air circulation. A highly efficient fan featuring an innovative blade design ensures the column is maintained in an ideal thermally quiet zone.

The oven is particularly designed for Optimum analytical performance in terms of accuracy and precision of retention data, and to avoid Peak distortion problems with low thermal mass columns.

INTERNAL COMPONENTS

The column oven is accessible by pulling forward the oven door lever. Opening the oven door activates a safety microswitch which automatically switches Off oven heating and the motor for the air circulation fans.

The injector inlets and detector outlets are provided on the roof of the oven. The exact specifications of the column Fittings are different depending on whether capillary or packed

column injector and detector base bodies are installed. Auxiliary gas lines where fitted end in an M8 x 1 male fitting between the injector and detector base bodies.

TEMPERATURE CONTROL

The oven is heated by resistor elements powered by a solid state relav (SSR) circuit located within the Control Unit. The oven temperature is monitored by a PT 100 platinum wire Sensor and controlled by the Control Unit. The maximum temperature is 450 "C. Three linear temperature ramps are possible or the temperature mav be programmed non-linearly using a Basic program running on the Control Unit.

The highest practical limit of temperature rate is 49.9 °Cmin ^-1 during initial ballistic programming as may, be required by splitless or cold on-column mjections.

The minimum operational temperature of the oven has been extended down to 5 OC above ambient by incorporatinuD, a modulating cooling flap, controlled by the Control Unit. Cool ambient air intake and hot air exhaust are proportioned according to the selected temperature Set point. The system is designed to allom, Separation of moderately volatile components on thick film capillary columns at near ambient temperatures without the use of a cryogenic system.

For operations at temperatures below ambient the Cryo 820 Control module is required (partno. 432 09810). This allows oven temperatures down to -50°C with carbon dioxide or -99 °C with liquid nitrogen.

DETECTOR BASE BODIES

There are nix detection Systems for the 8000 Serien Gas Chromatograph. This section will include only a brief description of each of the detector units for yöur Information and future reference. Full descriptions of the various detectors, covering installation, Operation and maintenance are available in separate manuals which may be inserted into Section 4 of this binder.

The detector options are fully and easily interchangeable. This is made possible by the presence on the analytical unit of "base bodies" that-constitute the connection between detector and analytical column. However, depending on the Instrument, not all gas lines for air, fuel and make-up may be present in the base unit. Kits are available for the installation of additional gas lines as required.

Two typen of detector base bodies are available depending on the base unit configuration you haue. The packed column base body (CB 70, fig 1.19) accepts all typen of glass and metal packed coluinns with outside diameters ranging from 4 to 6 mm. The column entern the compartment right up to the base of the detector j et which sits at the top of the base body. Hydrogen and make-up gas flow pass the end of the column. In this mannen dead volumes, and thereby column band broadening, are minimised.

Fig 1.19. CB 70 packed column detector base body

The capillary detector base body (CB 71) can accept either glass or fLised silica capillary   columns. The design permits the column to enter the detector Jet directly thereby eliminating any dead volumes. As shown in fig 1.20 the CB 71 base body allows columns to be connected using either M4 or M8x1 fittings.

Fig 1.20. CB 71 capillary detector base body.

Both detector compartments are contained in an aluminium block. For a block containing two detector base bodies heating is supplied by a single cartridge resistor of 200 W. When only one base body is mounted heating is supplied bv a pair of 70 W resistors. The temperature is monitored by a platinuni wire Sensor. The temperature range available for the detector block is 10 - 20 °C above ambient to 450°C, controllable in increments of 1 °C, but the usable temperature range will be dictated by the particular detector you wish to install.

The temperature of the hot wire detector unit is coiitrolled separately from the MAID Control unit described in the HWD detector manual.

FLAME IONJIZATION DETECTOR (FID)

The FID-80 detector has been designed to meet the Optimum performance in sensitivity and linear dynamic range.

Nearly all carbon based compounds from a few picograms to several milligrams entering the flame are linearly detected. The FID-80 geometry features high contamination resistance, ensuring stable, reproducible and long-term trouble-free performance.

Operating temperature Limits: 3 3 0 "C with the standard flame *et (part no. 404 01800) and upto450"C with ceramlc flame iet (pari no. 40404'DOO). The control unit is the EL 800 optional Electrometer unit which may be installed'in the GC Control Unit. In this case the electrometer unit will be drived by the Control Unit keyboard.

ELECTRON C TTURE DETECTOR (ECD)

The new model ECD-80 features a very lom- volume Ionisation chamber and increased contamination resistance which ensures high sensltl\-ityavoidingexcessivebroadeningofthe chromatographic peaks. This particular geometry allows the detector to be cleaned removing " the lonization chamber without disturbing the "NI source. The detector can be heated to 400 °C, extending its application range bv allowing analysis of higher molecular weight materials. The ECD Control module is designed to maximise the detector sensitivity 11     1 in constant current mode of oOperation.and lineaity i

NITROGEN-PHOSPHORUS DETECTOR- (NPD)

The NPD-80 features a high sensitivity, high stabillty and extended linear range for

the determination of nitrogen and phosphorus containing compounds. The operating c

temperature limit is 330 °C with the standard flame j et , and 450 °C with ceramic flame jet. The control unit is the NPD 800 control modale .

FLAME PHOTOMETRIG DETECTOR (FPD)

Basel on the flame photometric principle, this detector is available with two interchangeable filtern for sulphur (394 um) and phosphorus (526 nm) containing compounds and is on,- of the most selective GC detectors. The high sensitivity and good linear dynamic range (log scale for sulphur response) provide a unique tool for the trace determination of sulphur and phosphorus containing compounds in, for example, pesticide residue analysis, pollution control and Grude oll analysis. The control unit is the FPD 700 module. To simplify the quantitative analysis of sulphur, an optional module, the linearising module LIN 700, may be added to the FPD 700 control module.

HOT WIRE DETECTOR (HWD)

The thermal conductivity detector of Fisons Instruments features a new flow geometry of the cells to increase sensitivity and reduce the noise to the lowest possible level. To protect the filainents in case of interruptions to the carrier gas supply a Sensor automatically Guts Off power to the unit. The detector is installed separately on top of the bare unit and is controlled by the H1A7-D Control module.

The HWD Control module permits constant niean temperature operations ensuring a high degree of filament protection, amplification of the Output signal by a factor of 10 and a linear dynamic range exceeding 10 ⁴ .

PHOTOIONTIZATION DETECTOR (PID 800)

In the photoionization detector the sample eluted froin the chromatographic column is energized by a UV Iamp which emits photons atadeterininedenergythentheionesuenerated are collected in an electrode.

The type of lamp used determines the selectivity and sensitivity of the detector that, for its characteristics of high specificity, finds large applications in the determination of aromatic and policyclic hydrocarbons in the environmental field.

The new detector PID 800 may operate at temperatures up to 400 "C maintaining theLTV lamp also at low temperature. This allows the analysis of highboiling compounds avoiding their condensation in the ionization chamber and ensures a lono, life expectancy of the lamp. The control of the detector is carried out by the PID 800 control module.

MULTI-DETECTOR SYSTEMS

For the analysis of coinplex matrices a significant reduction in analysis time and increase in sample information may be gained with a iiitilti-detector system. Detectors may be arranged in parallel, or with the non-destructive ECD in series, to produce a number of chromatograms from each single injection. This may prove particularly useful for the bulk analysis of product formulations (finger printing), biochemical assavs and environmental studies, etc. For the analysis of unknown compounds the use of a multiple detection system improves selectivity, increases the number of detectable compounds and provides more information for component identification.

A standard Lit is available (part no. 190 04518) which enables a F1D80, FPD80 and NPD 80- FLdetector units to be mounted o-i the ECD-80. For parallel connection of detector units an effluent Splitter kit for fiised silica capillary columns is available under pari no. 190 04521 or, alternatively, low thermal mass press-fit connections are available.