Data quality improvement for field-portable gas chromatography-mass spectrometry through the use of isotopic analogues for in-situ calibration

Abstract

Environmental contextQuantitative field-based sampling of airborne volatile organics continues to be a challenge because of the absence of laboratory supplies and facilities. Approaches are required to overcome poor data arising from difficulties with calibration of fielded instruments. This method normalises responses across portable thermal desorption gas-chromatography mass spectrometers and requires no advance calibration, enabling accurate and precise use of previously established response factors ported from the laboratory to fielded instruments. AbstractSorbent capture provides a process for collecting airborne volatile organic compounds (VOCs) for analysis by thermal desorption gas chromatography-mass spectrometry (TD-GC-MS). Under typical laboratory conditions, analytical standards are readily available and calibration of instrumentation is a routine process. In contrast, field-portable instruments are standardised using a representative curve prepared on a limited number of instruments and then applied to fielded units. The performance of field-portable TD-GC-MS systems when deployed to multiple remote sites was studied, and a large variability in sensitivity and performance was observed when using the manufacturer-prescribed methods for calibration of instruments and normalisation of the data. This variability was remedied by the implementation of a non-interfering calibration that is pre-incorporated onto the sorbent media. Use of an in-situ calibration curve constructed using stable isotope labelled standards provided robust quantification, accuracy of measurement and diagnostic capabilities for malfunctioning fielded equipment. Pre-incorporation of isotopic analogues onto thermal desorption tubes in advance of field distribution greatly improves the accuracy and reproducibility of analyses and demonstrates, for the first time, definitive quantification of target analytes using field-portable GC-MS in an operational theatre.

Interpol review of the analysis and detection of explosives and explosives residues

“…Qualley, A., Hughes, G.T., and Rubenstein, M.H. report on a method of improving the data in field-portable GS-MS by using the “pre-incorporation of isotopic analogues (of the target analytes) onto thermal desorption tubes in advance of field distribution …” [ 346 ].…”

Tehnologije koje se primjenjuju za terensku detekciju bojnih otrova: II. dio – Detektori nove generacije

“…Za prijenosne GC-MS uređaje obično se upotrebljavaju kraće kolone (duljine 5 -15 m, unutarnjeg promjera 0,10 -0,25 mm i debljine premaza 0,4 -0,1 µm). 21,22 Primjenjuju se različite tehnike ionizacije (kemijska ionizacija, ionizacija elektronima, elektroraspršenje), a kao metoda uvođenja uzorka najčešće se primjenjuje injektiranje tekućine s mikroekstrakcijom na čvrstoj fazi i toplinskom desorpcijom. 19,[23][24][25][26] Prijenosni GC-MS uređaji većinom rade na principu hvatanja iona (engl.…”

Strategy for Sustainable and Green Chromatographic Separation Science: Innovation, Technology and Application

“…EME combined with HPLC-UV detection technique has been applied for the determination of melamine in the range of 7-8000 ng mL -1 (LOD of 2.0 -5.8 ng mL −1 ), with enrichment factor in the range of . In this approach, the extraction time was 15 min, which is much shorter when compared with the HF-LPME technique (60 min) that provided a detection limit of 0.003 mg kg -1 [72,73]. For exposed solvent microextraction modes, SDME and DLLME are among the popular techniques preferred by analytical chemists.…”