module Precursor:sig..end
type t = {
mslevel :int;
(* 1: MS, 2: MS/MS,... *)
mz :float;
(* MassToChargeRatio *)
z :float;
(* ChargeState *)
int :float;
(* Intensity *)
val mass : t -> floatmass p return the mass of the precursor p without charge.