Markes International is a specialist manufacturer of instrumentation for the detection of trace-level VOCs and SVOCs in liquids, solids and gases. Established in 1997, Markes has a well-deserved reputation as the worldâ€™s leading authority in analytical thermal desorption, manufacturing and selling a comprehensive range of instruments, sampling equipment and supplies that enhance the analytical capability of GCâ€“MS. Markes has a strong history of innovation in thermal desorption, now complemented by expertise in other sample preparation techniques including high-capacity sorptive extraction, SPME and headspace. In recent years Markes has also gained recognition for its innovative, high-performance time-of-flight mass spectrometers for GC,
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New at AQE 2018 is CentriÂ®, Markesâ€™ fully automated analyte concentration system for GCâ€“MS.
Centri marks a breakthrough in versatility and performance for the sampling and preconcentration of volatile and semi-volatile organic compounds from solid, liquid and gaseous samples, prior to GCâ€“MS analysis. For the first time, it combines capability for several popular sample introduction modes with full automation and trap-based preconcentration, all on a single platform.
The techniques available on Centri are: (a) headspace or immersive high-capacity sorptive extraction using HiSorbâ„¢ probes; (b) headspace sampling; (c) solid-phase microextraction (SPME); (d) analysis of sorbent-packed thermal desorption (TD) tubes. The system can accommodate standard 20 mL or 10 mL vials, has capacity for up to 50 TD tubes, and is automated by leading robotics technology (with the full automation of high-capacity sorptive extraction being a major instrumental advance).
Centri is beneficial to environmental, food, fragrance and clinical GCâ€“MS laboratories who struggle with time-consuming manual sample preparation, and want to improve their productivity by replacing these with a variety of automated solvent-free methods. Further benefits are provided by the availability of economical cryogen-free trapping â€“ a standard technique for TD and sorptive extraction protocols, but is one that is less often used for SPME and headspace sampling. Trapping improves sensitivity to the ppt level, allows selective purging of interferents such as water and solvents, and brings the ability to split and re-collect a single sample onto a clean sorbent-packed tube. This re-collection capability of Centri is particularly important, because it eliminates repetition of lengthy sample extraction steps, brings greater peace of mind by allowing storage of valuable samples, enables analysis of a wider concentration range by changing split flow ratios, and permits easy validation of complete analyte transfer.