GCxGC

Overview

The BTX is the latest generation of LECO’s Benchtop (or BT) GC-TOFMS series. For the past 8 years, the Pegasus BT series has proven reliability in labs performing unbiased, non-targeted analyses and tackling difficult matrices. A diverse spectrum of investigators—including those in industries like Petroleum, Life Sciences, Environmental Analysis, Pharmaceuticals, Food Safety, and others—have gained deeper insights into the complex chemistries of their samples thanks to the incredible Pegasus BT.

How it works

The ON736 Oxygen/Nitrogen system is designed for simultaneous measurement of oxygen and nitrogen content of steel and other inorganic materials. The instrument features custom software designed specifically for touch operation.

A pre-weighed sample is placed in a graphite crucible which is heated in an impulse furnace to release analyte gases. Oxygen present in the sample reacts with the graphite crucible to form CO and CO2. An inert gas carrier, typically helium, sweeps the liberated gases out of the furnace and through a Mass Flow Controller. The gas then flows through a heated reagent, where the CO is oxidized to form CO2, and H2 is oxidized to form H2O. Oxygen is detected as CO2 using a non-dispersive infrared (NDIR) cell. CO2 and H2O are then scrubbed out of the carrier gas stream. A Thermal Conductivity (TC) detector is used to detect the remaining nitrogen.

The detection system is comprised of both NDIR and TC detectors. NDIR cells are based on the principle that analyte gas molecules absorb infrared (IR) energy at unique wavelengths within the IR spectrum. Incident IR energy at these wavelengths is absorbed as the gases pass through the IR absorption cells. TC detection takes advantage of the difference in thermal conductivity between carrier and analyte gases. Resistive TC filaments are placed in a flowing stream of carrier gas and heated by a bridge circuit. As analyte gas is introduced into the carrier stream, the rate at which heat transfers from the filaments will change producing a measurable deflection in the bridge circuit.

The concentration of an unknown sample is determined relative to calibration standards. To reduce interferences from instrument drift, reference measurements of pure carrier gas are made prior to each analysis.

Instrument Support

Most companies offer 90 days—we offer 90 years (and counting). Access the same expert service whether you bought your equipment yesterday or years ago. From training to tech support, our responsive team of experts is ready to help you improve productivity and achieve success in laboratory.