Device for adjunctive detoxification of blood, the device including: a first fluid passage (407, 417) having a first fluid connection defining an upstream end and a second fluid connection defining a downstream end of the first fluid passage, the first fluid passage being adapted to receive blood at its upstream end and to return blood at its downstream end; a second fluid passage (435, 463) extending from a first location in the first fluid passage to a second location in the first fluid passage; a separator for separating at least one of blood cells and molecules of high and medium molecular weight from blood, the separator being arranged to effect separation between the first fluid passage and the second fluid passage; and at least one clearance or removal compartment arranged in the second fluid passage and adapted to subject a passing fluid, such as plasma or plasma water received from the separator to treatment, wherein the second fluid passage (435, 463) extends from a first location adjacent to the upstream end of the first fluid passage to a second location adjacent to the downstream end of the first fluid passage, such that the fluid of plasma or plasma water treated by the at least one clearance or removal compartment can be returned directly to the blood, characterized in that the at least one clearance or removal compartment comprises one or more aptamers to remove at least one of uremic toxins, groups of uremic toxins and precursor molecules of uremic toxins from the passing fluid of plasma or plasma water, wherein the second fluid passage is provided with a first flow control means and downstream of the first flow control means is connected to a component containing an ethylene diamine tetra acetic acid solution or any other Mg 2 +-ion-chelating or binding compound or structure, which component can be selectively connected to the second fluid passage by means of a control valve, and wherein a continued second fluid passage is provided with a second flow control means and upstream of the second flow control means, but downstream of the clearance or removal compartment, the continued second fluid passage gives access to a waste component via a waste control valve and a fourth flow control means in the form of a pump, such that the aptamers can be regenerated in the clearance or removal compartment. a first fluid passage (407, 417) having a first fluid connection defining an upstream end and a second fluid connection defining a downstream end of the first fluid passage, the first fluid passage being adapted to receive blood at its upstream end and to return blood at its downstream end; a second fluid passage (435, 463) extending from a first location in the first fluid passage to a second location in the first fluid passage; a separator for separating at least one of blood cells and molecules of high and medium molecular weight from blood, the separator being arranged to effect separation between the first fluid passage and the second fluid passage; and at least one clearance or removal compartment arranged in the second fluid passage and adapted to subject a passing fluid, such as plasma or plasma water received from the separator to treatment, wherein the second fluid passage (435, 463) extends from a first location adjacent to the upstream end of the first fluid passage to a second location adjacent to the downstream end of the first fluid passage, such that the fluid of plasma or plasma water treated by the at least one clearance or removal compartment can be returned directly to the blood, characterized in that the at least one clearance or removal compartment comprises one or more aptamers to remove at least one of uremic toxins, groups of uremic toxins and precursor molecules of uremic toxins from the passing fluid of plasma or plasma water, wherein the second fluid passage is provided with a first flow control means and downstream of the first flow control means is connected to a component containing an ethylene diamine tetra acetic acid solution or any other Mg 2 +-ion-chelating or binding compound or structure, which component can be selectively connected to the second fluid passage by means of a control valve, and wherein a continued second fluid passage is provided with a second flow control means and upstream of the second flow control means, but downstream of the clearance or removal compartment, the continued second fluid passage gives access to a waste component via a waste control valve and a fourth flow control means in the form of a pump, such that the aptamers can be regenerated in the clearance or removal compartment.