Carlos A Valdez1,2,3, Roald N Leif1,2,3, Alexander K Vu1,3, Edmund P Salazar1,3. 1. Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA. 2. Nuclear and Chemical Sciences Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA. 3. Forensic Science Center, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
Abstract
RATIONALE: Detection of 3-quinuclidinol (3Q), a marker for the chemical warfare agent 3-quinuclidinyl benzilate, is very difficult by gas chromatography-mass spectrometry (GC/MS), providing low, broad signals even when analyzed in isolated form. Therefore, a method that can convert 3Q into a substrate with enhanced detectability by GC/MS would be an important tool for its analysis. METHODS: 2,2,2-Trichloroethoxycarbonyl chloride (TrocCl) was used in the derivatization of 3Q in three different soils of varying composition and total organic content (Virginia type A soil, Nebraska EPA standard soil and Ottawa sand) when present at a 10 μg g-1 concentration in each. A direct derivatization protocol and one involving the pre-extraction of the analyte were evaluated for their individual efficiencies and subsequent analysis using electron ionization GC/MS. RESULTS: The practical derivatization of 3Q, when present at low levels (10 μg g-1 ) in three different soil matrices, was found to be rapid (1 h) and to take place smoothly at ambient temperature (and as low as 4°C). The method detection limit was determined to be 30 ng mL-1 for the Virginia type A soil, 49 ng mL-1 for the Nebraska EPA standard soil and 72 ng mL-1 for the Ottawa sand sample. CONCLUSIONS: An expedient and practical derivatization method for 3Q, a chemical warfare degradation product difficult to detect by GC/MS, has been realized using trichloroethyl chloroformate. The reaction provides 3Q-Troc, a derivative with better detectability than 3Q by electron ionization GC/MS such as peak sharpness and a unique mass spectrum for its unambiguous identification. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.
RATIONALE: Detection of 3-quinuclidinol (3Q), a marker for the chemical warfare agent 3-quinuclidinyl benzilate, is very difficult by gas chromatography-mass spectrometry (GC/MS), providing low, broad signals even when analyzed in isolated form. Therefore, a method that can convert 3Q into a substrate with enhanced detectability by GC/MS would be an important tool for its analysis. METHODS:2,2,2-Trichloroethoxycarbonyl chloride (TrocCl) was used in the derivatization of 3Q in three different soils of varying composition and total organic content (Virginia type A soil, Nebraska EPA standard soil and Ottawa sand) when present at a 10 μg g-1 concentration in each. A direct derivatization protocol and one involving the pre-extraction of the analyte were evaluated for their individual efficiencies and subsequent analysis using electron ionization GC/MS. RESULTS: The practical derivatization of 3Q, when present at low levels (10 μg g-1 ) in three different soil matrices, was found to be rapid (1 h) and to take place smoothly at ambient temperature (and as low as 4°C). The method detection limit was determined to be 30 ng mL-1 for the Virginia type A soil, 49 ng mL-1 for the Nebraska EPA standard soil and 72 ng mL-1 for the Ottawa sand sample. CONCLUSIONS: An expedient and practical derivatization method for 3Q, a chemical warfare degradation product difficult to detect by GC/MS, has been realized using trichloroethyl chloroformate. The reaction provides 3Q-Troc, a derivative with better detectability than 3Q by electron ionization GC/MS such as peak sharpness and a unique mass spectrum for its unambiguous identification. Published 2021. This article is a U.S. Government work and is in the public domain in the USA.
Authors: Carlos A Valdez; Roald N Leif; Robert D Sanner; Todd H Corzett; Mark L Dreyer; Katelyn E Mason Journal: Sci Rep Date: 2021-11-18 Impact factor: 4.996