The Purge and Trap Autosampler: Suggestions for Choosing the Right Model
A purge and trap autosampler helps scientists analyze trace level compounds in numerous substances. Substances that a purge and trap inlet prepares for chromatographic evaluation include: paint and other coatings, cosmetics, meals, soil, and water. The purging and trapping method is generally performed on samples that are tested for Volatile Organic Compounds (VOCs), which are carbon-based substances that vaporize at space temperature, and are recognized to trigger health problems. When a sample is ready for analysis, it undergoes the following method:
- The autosampler locations the sample in the column inlet
- Carrier gas bubbles by means of the sample to free of charge the compounds
- The compounds are trapped on the absorbent material of the column
- The column heats till the compounds vaporize
- The compounds travel via carrier gas into the gas chromotograph
All autosamplers that are developed for purging and trapping carry out this method, but distinct models offer various levels of performance. Under are tips for selecting a purge and trap autosampler for the evaluation of VOCs and other trace level compounds:
Consider Buying Used Gear
Buying utilized lab gear is a wise choice. Despite costing much less than new gear, utilized lab equipment frequently performs like new. This is simply because most lab gear is utilized non-strenuously and is effectively maintained. Simply because some organizations frequently replace lab gear to sustain funding, it is feasible to locate pre-owned gear that is basically new.
Evaluate Mechanical Robustness
The standard weak spot of a purge and trap autosampler is the arm that transports samples to the concentrator. Ideally, the arm must be reinforced to stop loose operation and sagging. An additional important mechanical component is the injection mechanism. Injectors that rely on syringes normally experience much more errors than other injectors. Consequently, choosing a model that does not use syringes is suggested.
Evaluate Carryover Prevention
Because purge and trap autosamplers procedure samples that include trace level compounds, locating an autosampler that has an superb method for carryover prevention is crucial. Maintaining the water in the pathway hot by using a hot water rinse in a fixed loop, and flushing the soil needle and transfer line with P&T Bake gas are efficient strategies for preventing carryover.
Evaluate Analytical Performance
A high-overall performance autosampler normally features a programmable, electronic delivery of 1ul-100ul without the require for priming. These traits define an IS/Surr delivery method that is acceptable for professional laboratories.
Choose Equipment for Soil and Water Samples
Since Gas Chromatography (GC) is used to analyze solid and liquid samples, choosing an autosampler with a tray that holds both strong and liquid samples is beneficial. Picking gear that holds each samples also aids laboratories economize on space and cash by possessing one autosampler for each kinds of samples as an alternative of splitting them among two units.