The Micro-QT is a next generation gas valve offering uncompromising leak-tight performance in an ergonomic design. The Micro-QT is also versatile, providing numerous connection options to cover a wide range of applications. Once the valve is connected to tubing using compression fittings, mating male and female valve ends is literally just a quick “snap”.
Originally designed for environmental air sampling and analysis, the Micro-QT has found a place in numerous other applications. Micro-QT’s feature a distinctive bright and colorful Silonite coating that prevents gas phase compounds from interacting with the metal surface. The rugged, solid design stands up to thousands of connections, while maintaining leak tight operation. For scientists and professionals working with VOC and SVOCs, the Micro-QT’s compact internal volume reduces exposure to potentially contaminated surfaces and allows for easy cleaning.
The Micro-QT™ Valve is optimized for volatile and light semi-volatile compounds. The Micro-QT™ Valve is compatible with all existing Entech sampling devices by simply adding a female Micro-QT™ to ¼” adapter (PN 30-22800).
The Micro-QT™ is a next generation pneumatic valve offering uncompromised leak-tight performance in an ergonomic design. The Micro -QT™ is also versatile, providing numerous connection options to cover a wide range of applications. Once connecting the valve to tubing using compression fittings, mating male and female valve ends is literally just a quick “Snap!”
Originally designed for environmental air sampling and analysis, the Micro-QT™ has found a place in numerous other applications. Micro-QT’s feature a distinctive bright and colorful Silonite™ coating that prevents gas phase compounds from interacting with the metal surface. The rugged, solid design stands up to thousands of connections, while maintaining leak tight operation. For air, gas, and headspace sampling professionals, the Micro QT’s™ compact internal volume reduces exposure to potentially contaminated surfaces and allows for easy cleaning.
This is the complete Entech 2018 Catalog. You can download the PDF or use our Flipbook viewer (below) for a smoother experience. Please note that not all sampling products are included. The Entech store is the best place to find photos and descriptions of every product we carry.
The analysis of Air Toxics TO-15 compounds in air by GCMS requires the accurate preparation of low level standards to fulfill 3 distinct requirements:
1 Create GCMS response factors for each target compound across the full range of expected concentrations
2 Validate the canister preconcentration system for consistent preconcentration and matrix management without loss of target compounds during analysis by GCMS
3 Provide inexpensive preparation of low level standard to allow recovery testing of all sampling canisters in a laboratory’s inventory for inertness validation
The ability to meet item #1 could simply be achieved by performing a loop injection of high concentration standards, but this would not meet the requirements of #2 and #3, which require the standards to be diluted down to ambient levels, often times below 1 PPBv. As described in more detail later, it is best to use at least 2 standards when creating a GCMS calibration curve, as this typically allows method calibrations over a wider concentration range, often times up to 1000x or more.
Large concentration ranges can reduce the number of dilutions and reruns that are necessary by a laboratory, thereby increasing productivity. For example, generating a calibration curve from 0.04PPBv to 40 PPBv would allow all samples within this range to be quantified without further dilution, whereas reducing the range to just 0.04PPBv to 4 PPBv would require any samples with target compounds in the range of 4 to 40 PPB to be rerun using smaller sample volumes, or after diluting a representative aliquot into a second canister.
Items #2 and #3 in the previous list are extremely important when performing accurate TO15 analyses, yet are often not given the consideration they deserve.
Creating standards that are as similar to the concentration and matrix of real samples is critical to prove that target compounds will be recovered properly during the preconcentration and matrix elimination process. Although calibration standards are stable in Silonite coated canisters without the presence of water, it is recommended that canisters be made up with between 50-70% relative humidity just so the sample preparation system can be challenged just as it will be with real samples. A discussion follows that describes how moisture levels in this range can be used to challenge the analytical system with extremely large or small amounts of total water just by varying the preconcentration volume.
The TOV-2™ Toxic Organics Valve has been specifically designed to ensure complete recovery of low-level TO-14a and TO-15 target compounds. A pack less system features an ultra-compact, passivated sample path with no internal weld scars, and a Silonite™ coating option for superior inertness and durability. The TOV-2 has Entech’s exclusive NF technology that uses replaceable nickel ferrules that exhibit less carryover relative to replaceable vespel or V/G ferrules. The TOV-2’s new “sure-seal” valve seat creates a leak-tight seal even more easily than before. A low-cost kit is available so you can easily maintain valves at the peak of scientific reliability and performance. The TOV-2 Valve is the only repairable valve on the market! Ask your Entech Analytical Solutions Manager or Distributor about how this advancement can deliver maximum recovery with minimal carryover for assured compliance with new lower level VOC methods.