Desorption electrospray ionization–mass spectrometric analysis of low vapor pressure chemical particulates collected from a surface

• DESI–MS analysis of low vapor pressure chemical particulates collected from a surface.
• Investigated collection of low vapor pressure chemical particulates from surfaces.
• Successfully analyzed chemical particulates collected on sticky screen sampler using DESI–MS.
• Demonstrated µg level detection limits for chemical particulates.
• Normalized data against the total ion current (TIC) enabling good reproducibility.
• Successfully determined mass of TEP in a sample with 14% accuracy.

The collection of a low vapor pressure chemical simulant triethyl phosphate sorbed onto silica gel (TEP/SG) from a surface with subsequent analysis of the TEP/SG particulates using desorption electrospray ionization–mass spectrometry (DESI–MS) is described. Collection of TEP/SG particulates on a surface was accomplished using a sticky screen sampler composed of a stainless steel screen coated with partially polymerized polydimethylsiloxane (PDMS). DESI–MS analysis of TEP/SG particulates containing different percentages of TEP sorbed onto silica gel enabled the generation of response curves for the TEP ions m/z 155 and m/z 127. Using the response curves the calculation of the mass of TEP in a 25 wt% sample of TEP/SG was calculated, results show that the calculated mass of TEP was 14% different from the actual mass of TEP in the sample using the m/z 127 TEP ion response curve. Detection limits for the TEP vapor and TEP/SG particulates were calculated to be 4 μg and 6 particles, respectively.

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