An analytical device for analyzing ions is provided comprising a separator for separating ions according to a physico-chemical property and an interface comprising one or more ion guides. A quadrupole rod set mass filter is arranged downstream of the interface. A control system is arranged and adapted: (i) to transmit a first group of ions which emerges from the separator through the interface with a first transit time t1; and (ii) to transmit a second group of ions which subsequently emerges from the separator through the interface with a second different transit time t2.

Separation of materials is achieved using affinity binding and acoustophoretic techniques. A column provided with a fluid mixture of materials for separation and support structures may be used with acoustic waves to block flow of the support structures. The support structures can have an affinity for one or more materials in the fluid mixture. By blocking flow of the support structures, materials bound or adhered to the support structure are also blocked.