English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Gas phase reactions between hydrated protons H + (H 2 O)  n  and a substance M, as seen in atmospheric pressure chemical ionization (APCI) with mass spectrometry (MS) and ion mobility spectrometry (IMS), were modeled computationally using initial amounts of [M] and [H + (H 2 O)  n  ], rate constants k  1 to form protonated monomer (MH + (H 2 O)  x  ) and k  2 to form proton bound dimer (M 2 H + (H 2 O)  z  ), and diffusion constants. At 1 × 10 10 cm -3 (0.4 ppb) for [H + (H 2 O)  n  ] and vapor concentrations for M from 10 ppb to 10 ppm, a maximum signal was reached at 4.5 μs to 4.6 ms for MH + (H 2 O)  x  and 7.8 μs to 46 ms for M 2 H + (H 2 O)  z  . Maximum yield for protonated monomer for a reaction time of 1 ms was ∼40% for k  1 from 10 -11 to 10 -8 cm 3 ·s -1 , for k  2 / k  1 = 0.8, and specific values of [M]. This model demonstrates that ion distributions could be shifted from [M 2 H + (H 2 O)  z  ] to [MH + (H 2 O)  x  ] using excessive levels of [H + (H 2 O)  n  ], even for [M] &gt; 10 ppb, as commonly found in APCI MS and IMS measurements. Ion losses by collisions on surfaces were insignificant with losses of &lt;0.5% for protonated monomer and &lt;0.1% for proton bound dimer of dimethyl methylphosphonate (DMMP) at 5 ms. In this model, ion production in an APCI environment is treated over ranges of parameters important in mass spectrometric measurements. The models establish a foundation for detailed computations on response with mixtures of neutral substances.

Parametric Sensitivity in a Generalized Model for Atmospheric Pressure Chemical Ionization Reactions