Field portable low temperature porous layer open tubular cryoadsorption headspace sampling and analysis part II: Applications

Abstract

This paper details the sampling methods used with the field portable porous layer open tubular cryoadsorption (PLOT-cryo) approach, described in Part I of this two-part series, applied to several analytes of interest. We conducted tests with coumarin and 2,4,6-trinitrotoluene (two solutes that were used in initial development of PLOT-cryo technology), naphthalene, aviation turbine kerosene, and diesel fuel, on a variety of matrices and test beds. We demonstrated that these analytes can be easily detected and reliably identified using the portable unit for analyte collection. By leveraging efficiency-boosting temperature control and the high flow rate multiple capillary wafer, very short collection times (as low as 3 s) yielded accurate detection. For diesel fuel spiked on glass beads, we determined a method detection limit below 1 ppm. We observed greater variability among separate samples analyzed with the portable unit than previously documented in work using the laboratory-based PLOT-cryo technology. We identify three likely sources that may help explain the additional variation: the use of a compressed air source to generate suction, matrix geometry, and variability in the local vapor concentration around the sampling probe as solute depletion occurs both locally around the probe and in the test bed as a whole. This field-portable adaptation of the PLOT-cryo approach has numerous and diverse potential applications.

Research trends in forensic science: A scientometric approach to analyze the content of the INTERPOL reviews

“…Raman spectroscopy has become field-portable as reported in the study by Shand on analyzing samples (chemicals, drugs and explosives) at the crime scene (Shand, 2008). Other portable devices reported in the IFSMS references lists include: PLOT-cryoadsorption (Bruno, 2016;Harries et al, 2016), GC-TMS (Fredeen et al, 2010), GC-MS (Bednar et al, 2012), GC-MS/MS (Prieto et al, 2005), XRF (Bergslien et al, 2006;Rold an et al, 2010), and OR NIR (Morillas et al, 2018).…”

Field portable low temperature porous layer open tubular cryoadsorption headspace sampling and analysis part I: Instrumentation

“…These applications are discussed fully in the companion paper, Field-portable low temperature porous layer open tubular cryoadsorption headspace sampling and analysis part II: pplications. [34]…”

“…A companion paper (Part II) presents examples of some of these applications. [34] There are four primary aspects to making the approach functional in the field: (1) the design and construction of a portable PLOT-capillary platform, (2) the design and construction of an appropriate supporting equipment platform, (3) the design of the service interface between the PLOT-capillary platform and the supporting equipment platform, and (4) the design and construction of suitable probes used to collect vapors. In particular, the portable PLOT-cryo capillary platform must be made field operable and robust (i.e., without the amenities of the laboratory), the supporting equipment platform must be made lightweight, portable and robust, the service interface between the PLOT capillary must be made flexible and efficient, and a selection of stand-off probes of different sizes and configurations to allow sampling in soil, under concrete slabs, in tanks, freight containers, motor vehicles, etc., must be available and reliable.…”

Composition of the C6+ Fraction of Natural Gas by Multiple Porous Layer Open Tubular Capillaries Maintained at Low Temperatures

“…Detailed information on the development of multi-PLOT-cryo instrumentation and associated applications can be found in previous papers; , hence, only a brief description will be provided here. Bundles of six individual capillaries [made from an alumina (a highly retentive, polar adsorbent) PLOT column with a 0.32 mm inside diameter] were embedded in epoxy to form a wafer equipped with compression fittings (Figure ).…”