Firma:              Perkin Elmer

Modell:            Autosyst 1022 P

Kommentar:   Dokumente engl.

Introduction

What Is the 1022 GC Plus?

The 1022 GC Plus is a gas chromatography system made up of hardware and software that collects, stores, and processes chromatographic data.

The features included in the 1022 GC Plus were carefully de­signed to increase laboratory productivity and throughput, and yet still retain the ease-of-use and versatility all opera­tors desire. The 1022 GC Plus includes all the vital features required for efficient chromatographic analysis; among these are

n          Control of the GC functions and the autosampler through software

n          Data collection from two detectors using the saure method (with the two-channel Option)

n          Real-time display of the sample chromatogram

n          Replots of stored chromatograms

n          Sample analysis reports, customized to your needs

n          Batch reprocessing of multiple sample runs

n          Archive analytical results to dick for permanent record

This tutorial assumes you haue a 1022 GC Plus data collec­tion system: This includes the Autosystem GC configured with at least one injector/detector (autosampler is optional), at­tached to a single-channel Model 1022 Personal Integrator. The screens shown in this tutorial are for a single-channel system. Screens for dual-channel systems may contain addi­tional Information.

The 1022 GC Plus provides easy access to all of the above features and more by virtue of screen Windows and drop­down menus. From startup, the top-level screen's menu al­lows you to choose the work environment of your choice.

About the Keyboard

The keyboard is your link to the software. The keyboard has 35 color-coded keys divided into the following groups:

•            Function keys -- blue

•            Parameter keys -- white

•            Entry keys -- gray and black

•            Control keys -- yellow (The [Run] key is green.)

An audible short beep sounds every time a key is pressed. A long beep sounds when an error has been committed. The key groups and their locations arg illustrated in Figure 1-3.

Optional

(Description, depend on equipment)

RD Overview

Flame lonization Detectors are mass sensitive and used for the destructive analysis of organic compounds.

On entering the detector, the Sample is mixed with hydrogen and then burned in air, generating ions. These are collected and measured by the detector, the concentration being proportional to the amount of compound present.

Ion collection is enhanced by a polarized electric Field created by applying a negative voltage (—200 volts) to the jet tip.

Sensitivity is affected primarily by the hydrogen flow. A schematic of an FID is shown below.

Setting up a TCD n

TCD Overview

The Thermal Conductivity Detector is a dual channel detector which measures the difference in thermal conductivit) betwecn carricr gas flowing through a reference channel and carller gas + samplc flowing through an analytical channel.

Four tungsten-rhenium filaments are connected in a bridge circuit, two in cach channcl. The TCD is set up wich the saure amount of carricr gas flowing through both channels. The presence of a samplc component in the carricr gas flowing through the analytical channcl changes the resistance of the filament.s in that channel. This unbalances the bridge and produces a signal proportional to the amount of sample

.

Using a TCD With the Autosampler

When using a TCD wich a GSV (Gas Sampling Valve) or the autosampler at high sensitivity, a minor baselirre upset may occur at the time of injection.

If the signal goes below zero, incorporate a timed event Autozero to bring the signal back before peaks of interest elutc.

Observe the initial chromatogram to deter ine the entry to makc f or the timcd event.

Controlling the Autosampler 9

The autosampler contains three basic parts: a syringe tower, a turntable, and a sample tray (see Figures 9-1 and 9-2). The syringe tower can contain either a 0.5-µL, 5.0-µL, or 50.0-µL syringe. The sample tray contains positions for eighty-two 2-mL sample vials. The turntable contains one priority sample vial, four 4-mL waste vials, and four 4-mL wash vials.

Controlling the Autosampler

The autosampler can be configured to operate in one of two modes, single or multi program.

•            Single-program mode -- In this mode the autosampler runs a single autosampler program that specifies which injecior is to be used, the size of the injection, and the number of injections per vial. Samples are injected sequentially starting with the fii occupied vial position until no additional vials are detected. The GC is controlled by the parameters in the Active Method.

•            Multi-program mode -- In this mode the autosampler runs two programs consecutively. Each program specifies: the method to be used (each program can u a different method if desired), which injecior to use, the size of the injection, the number of injections per vial, and the starting and ending vial numbers. As each program is run, the system sets up the specified method as the Active Method.

The remainder of this chapter includes the following procedures and topics:

•            Setting Up Syringe Wash Parameters

•            Setting Injection Mode Parameters

•            Running Samples in Single Program

•            Running Samples in Multi Program

•            Other Autosampler Tasks