L10 ion chromatograf

HPLC analysers - L10 ion chromatograph

is a compact analytical ion chromatograph with integrated conductometric detector CD DUO and microsyringe pump LINAR 30, together with a column oven and manual loop injector. A simple capillary ion suppressor with inert membrane pump is delivered in a basic version. System is controlled by microprocessor, graphic display and keyboard. External control is possible (serial line).

The heart of the unit is linear pump  LINAR 30. Its stainless steel precisely polished cylinder has volume 30 ml. A piston with front PTFE sealing is mounted on a special ball screw which is connected to the gearbox and step motor. Mechanical pump part is situated in chromatograph box in horizontal position and the cylinder is slightly inclined to secure that all air bubbles leave lightly the cylinder (see Fig 2). Input high pressure solenoid valve is combined with a output ball valve (corundum ceramics). On the output line is inserted a low volume pressure gauge. 

The suction (full cylinder within 2 min.) can be done either manually or automatically when pump stop the action. The flow rate calibration is enabled using special password. Upper pressure limit setting is available.

System employs a conductivity detector CD DUO. It has two important features - signal sampling on the pulse end and two cells (measuring reference) conductivity comparison. Common conductivity detectors utilize square AC pulses on electrodes and integral current is measured. It brings a inaccuracy, as pulses are deformed due non-conductivity influences.

CD DUO circuits select from each pulse only its end where the current is measured (see the picture 3). In addition the measured current is directly compared with the reference cell signal. Reference cell is filled with the same electrolyte as measuring one and their differences appear only in time when sample zone is present.

Comparative measurement  further decrease nonconductive effects and eliminates partially temperature changes effect. Both used tenets results in practically noiseless signal even in high sensitivities.

Column oven is a solid state one with possibility to set the temperature up to 99 °C. For special purposes a cooled oven can be delivered. Standard six port manual loop injector with a polyimide rotor is delivered having 20 ul loop. Other loop volumes are available.

CHROM L10 LION ion chromatograph can be utilized with arbitrary ion columns  with I.D. in the range 1 - 5 mm. Cylinder volume is large enough to secure 30 minutes analysis with 4,6 mm I.D. Column.