The hardware
The fully automated headspace sample analysis ensures high flexibility, excellent reproducibility and a high throughput. The 600 ml injection chamber (patent pending) has been designed to optimize sensitivity and minimize contamination from less volatile components and so avoid memory effects. For on-line analysis an optional inlet device can be installed.
This instrument, based on a Inficon quadrupole mass analyzer, offers high sensitivity, stability and ease of use. The mass range (1-200 amu) is adequate for most types of applications in odor analysis. Moreover, for very specific uses, the SMart Nose®-300 instrument can offer additional information.
The options
The SMart Nose® options can be installed with the standard system, or ordered later. The options are easy to install and require only small adjustments of the system.
- On-line device : heated transfer line (100 cm, 30-200°C) fitted with a quartz capillary. The heating regulation can be switched externally from measuring chamber to on-line configuration. The volatile or semi-volatile compounds present in air, or in a specific open device can be analyzed continuously.
- Switching micro-valve : an optional switching valve can link together both measuring chamber and on-line capillaries to the mass spectrometer. Thus there is no need to change the configuration manually. The valve has a very low internal volume, and is actuated manually (screwdriver switch).
- Pyrolyzer : the SMart Nose® pyrolyzer device can be fitted directly on the measuring chamber. It is composed of a heating furnace (up to 1000°C), a quartz liner, a furnace and septum purge, and an electric controller. The pyrolysis occurs at high temperatures under nitrogen inert gas (non oxidative thermal decomposition). The evolved gases are transferred in the measuring chamber and analyzed.
- Bar-code identifier : optical device that can read bar codes. The samples are labeled with bar codes containing sample information. They are read by the identifier before incubation.
- Olfactometer : sniffing device connected to the system outlet. Fitted with moist air carrier, the extra sample headspace can be sniffed during the injection.
- Pre-concentration systems : there are several preconcentration systems available, based on the same principle. The headspace is first generated in the incubator, and then concentrated on an adequate adsorbent. The contents are finally quickly desorbed and analyzed. 2 systems availlable: SPME (Solid Phase Micro-Extraction) and INDEx (Inside Needle Dynamic Extraction).
Two operational modes
Two modes of operation are available: the survey mode and the multiple channel mode (up to 64 channels). The survey mode is used to identify the ions (channels) carrying the most significant information for the characterization and discrimination of unknown samples. On the other hand, to analyze and compare large sets of samples, the multichannel mode may be preferred. In this mode, each channel is a specific detector and the parameters (dynamic range, dwell time and resolution) can be set independently. The different analysis methods are stored on the hard disk and can be reloaded at any time allowing a flexible, reproducible and multipurpose instrument.
The software
The Quadstar™ software from Inficon, used to control the spectrometer, takes care of the mass calibration of the quadrupole, the data acquisition and the processing. Sequences (macro commands) allows automated experiments or specific programmed actions. Here are some examples.
- Measuring sequences : allows to run many samples from the autosampler. The analysis is conducted automatically with user defined parameters.
- Purge sequence : allows to do an automatic cleaning of the measuring chamber.
- Calibration sequence : allows to calibrate the mass spectrometer with a series of actions launched together
- Other sequences available on demand, or user specific sequence development.
In addition, the SMart Nose® software has been designed to process the raw mass spectrometric data using statistical algorithms such as Principal Component Analysis (PCA) or Discriminant Function Analysis (DFA), to yield a more user friendly representation of the results.
Specifications
Autosampler : Sample headspace injected by syringe.
- Capacity of 32 x 10 / 20 ml or 98 x 2 ml vials (2 x 32 or 2 x 98 optional).
- Heated syringe (30-150°C) of 2.5 ml (other volumes available on demand).
- Agitated oven for incubation / desorption, ranging from 30-200°C.
- Bar code identification (optional).
- Cycle Composer software (for pre-concentration options)
Mass spectrometer: Quadrupole analyzer with two stages pumping.
- Primary pumping by a membrane pump.
- High vacuum pumping by a turbomolecular pump.
- Mass range from 1 to 200 AMU (optional: 1-100 or 1-300).
- Electron impact ionization at 70 eV (2 tungsten filaments).
- Fully adjustable source and emission parameters.
- Ion detection by either a Faraday cup or a Channeltron SEM.
SMart Nose® system : mass spectrometer, autosampler, basis plate and computer.
- Size : Length x width x height : 95 x 75 x 91 cm.
- Weight : 75 kg
- Power : 300 W standard operating mode; 600 W baking mode.
- Purge gas : N2 , He or air; minimal pressure required: 1.5 bar.
- Data system : Pentium based PC running Windows 98 or higher.
- Location : Clean (no dirt or contaminants) and cool room. Stable and strong table, minimal dimensions 150 x 80 cm.
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