A device comprising: a source configured to generate ions from constituent components of the sample; a mobility cell having a gas inlet and a gas outlet opposite the inlet along a first direction such that a gas flow introduced at the gas inlet would flow in a first direction to the gas outlet, an ion entrance; a plurality of electrodes (502, 506) configured to generate an electric field gradient in a second direction, such that ions entering the mobility cell flow in the first direction with the gas and drift according to their mobility in the gas in the second direction, wherein an angle between the first direction and the second direction is between 45° and 135°; a plurality of ion exit orifices positioned opposite the ion entrance along the second direction defined by the electric field gradient and offset from the ion entrance and spaced apart from one another along the first direction; and a plurality of ion channels (316, 400) arranged parallel to one another and arranged adjacent to the mobility cell at the plurality of ion exit orifices, the ion channels (316, 400) configured to receive and accumulate ions from the mobility cell such that ions entering an individual channel (316, 400) have a range of ion mobilities that is different from a range of ion mobilities for ions entering an adjacent ion channel (316, 400); a mass analyzer configured to determine the mass-to-charge ratio of the ions; and a transfer guide configured to transport ions from the plurality of ion channels (316, 400) to the mass analyzer; wherein a gas pressure within the mobility separator is between 1 Torr to 20 Torr. a source configured to generate ions from constituent components of the sample; a mobility cell having a gas inlet and a gas outlet opposite the inlet along a first direction such that a gas flow introduced at the gas inlet would flow in a first direction to the gas outlet, an ion entrance; a plurality of electrodes (502, 506) configured to generate an electric field gradient in a second direction, such that ions entering the mobility cell flow in the first direction with the gas and drift according to their mobility in the gas in the second direction, wherein an angle between the first direction and the second direction is between 45° and 135°; a plurality of ion exit orifices positioned opposite the ion entrance along the second direction defined by the electric field gradient and offset from the ion entrance and spaced apart from one another along the first direction; and a plurality of ion channels (316, 400) arranged parallel to one another and arranged adjacent to the mobility cell at the plurality of ion exit orifices, the ion channels (316, 400) configured to receive and accumulate ions from the mobility cell such that ions entering an individual channel (316, 400) have a range of ion mobilities that is different from a range of ion mobilities for ions entering an adjacent ion channel (316, 400); a mass analyzer configured to determine the mass-to-charge ratio of the ions; and a transfer guide configured to transport ions from the plurality of ion channels (316, 400) to the mass analyzer; wherein a gas pressure within the mobility separator is between 1 Torr to 20 Torr.