Direct Inlet accessory for headspace vapours Brochure0 pages

Multi-purpose Direct Inlet Accessory
Direct sampling / concentration of
headspace vapours
The Multi-purpose Direct Inlet Accessory (U-INLET)
may be added to any manual UNITY thermal
desorption platform to provide a simple and
convenient mechanism for direct introduction / 'on-line'
sampling of headspace vapours from a wide range of
bulk sample containers. Vapours are either pumped or
swept through an inert, heated sampling line directly
into the electrically-cooled focusing trap of UNITY
without first being collected on a sorbent tube. After
sample collection, the focusing trap is thermally
desorbed to initiate analysis. The entire sampling and
analysis process may be carried out on- or at-line and
facilitates analysis by real-time detectors (enose
sensor arrays, process MS, etc.) as well as laboratory
GC(-MS).
The Direct Inlet Accessory comprises a purge line
(which may be used to direct carrier gas into the
sample vessel) and a heated inert sampling line
through which headspace vapours are pumped or
purged straight into the focusing trap. Sampling times
and sequences are all controlled using a dedicated
mode of UNITY software. The accessory may be used
to sample vapours from the same vessel semicontinuously
in a user-defined sequence. This is
either done to increase the total volume of vapour
sampled and enhance sensitivity or to monitor
changes in vapour composition over time. UNITY and
the Direct Inlet Accessory may also be combined with
some commercial headspace systems to automate the
concentration and analysis of multiple samples.
Applications
Key application areas include:
..characterisation of VOC profiles from natural
products and manufactured goods - food, flavour,
fragrance analysis
..measurement of residual volatiles in materials
..monitoring emissions from living organisms -
plants, microbes, fungi, insects, etc.
..monitoring trace VOC pollutants in environmental
water and soil samples
..off-odour / shelf-life testing
..monitoring organic vapour products from gasphase
reactions.
Registered in England No. 3414783 VAT Registration 700 8403 76
Mi BINLET
Figure 1. Example schematic of UNITY TD - Analysis system configured with the Direct Inlet Accessory.
Direct Inlet Accessory and
connections
Sample vessel
UNITY TD
GC-(MS)
detection
Optional
parallel
detection
e.g. enose,
direct MS
etc.