[ETOX]

Hi
PH solution in Mass Spectrometry,
this is related to PH in the solution (solvent+analyte) in source of mass spectrometry (ESI mode) which reflect initial (before creating the droplet)and then the PH final (after creating the droplet).
in short, I have to find PH final where I do have PH initial, the result is written but I do not know how the calculation was done.

pHfinal=  -log([H+] elec+ [H+] initial)
where [H+]initial= 10-pH initial
[H+] elec can be calculated from Faraday's law
and expressed as [H+] elec = ies/nFvf
where i ES is the ES current 0.1uA, n is the molar equivalent of electrons involved in the production of
one mole of H+ (in this case n = I), F is the Faraday constant (9.648 x 104 C mol-I), and vf is the solution flow rate through the ES capillary 10uL

PH initial is 7 and final is 5.2
the question is how 5.2 was calculated? and what if the PH initial 3


P