No Loss, No Drip Fraction Collection

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The Application Notebook

The Application Notebook, The Application Notebook-06-01-2010, Volume 0, Issue 0

LEAP has developed a new instrument for collecting the entire mobile phase stream during metabolic profiling HPLC–MS analyses into a sealed, 96-well, LTuma plate.

David P. Holub, Peter Smith, and Zach Dai, LEAP Technologies, Inc.

LEAP has developed a new instrument for collecting the entire mobile phase stream during metabolic profiling HPLC–MS analyses into a sealed, 96-well, LTuma plate. There are currently no alternative "off-the-shelf" collectors which can do this. Drop collectors make it possible for a droplet to miss a collection site during a well-to-well move, causing contamination and cannot pierce sealed plates. Solenoid collectors do not collect the entire stream, as the flow is diverted to waste during a well-to-well move. Loss of sample, and ultimately time, can lead to repeat studies and add to the overall cost of development. Spills of radiolabeled compounds are, in their own right, a nightmare for any health and safety team.

LEAP developed the Collect PAL, modifying CTC Analytics PAL platform, in order to address the biotransformation laboratory's requirements. The system supports temperature control (4–40 °C) of the collected fractions. In its maximum capacity the Collect PAL can hold 24 trays, and can collect into 96- and 384-well plates, as well as 2-, 4- or 8-mL vials. LEAP Shell software controls the instrument and many application parameters are user specified to fit the methods and conditions as required. The Collect PAL has a proprietary syringe mechanism for total stream collection.

Experimental Set-up for the Gravimetric Study

  • Isocratic HPLC pump, 5 mL/min — isocratic

  • 0.05" ID Peek tubing from pump to PAL

  • Tare and Net Weight 2.0 mL, 12 × 32 mm, septa-capped vials using LEAP's Balance PAL

  • HTC Collect PAL version equipped with Ambient 6-position Stacks

  • LEAP Shell v3.0 with Collect PAL Application release 1.7

  • 100% ACN – HPLC Grade

  • 50:50 DI H2O: ACN HPLC Grade

  • 100% MeOH – HPLC Grade


The gravimetric data supports the new technology and shows LEAP meets the requirements as outlined. These gravimetric experiments are supported by more than 20 systems operating in the USA and Canada running radiolabeled experiments. Using typical LC mobile phases, two flow rates were examined and 54 vials collected at different collection times per well settings. Table I displays these results. The Collect PAL was able to provide great precision from 0.6–4.1% CV of the anticipated delivery weight to each vial. Further studies have shown that the Collect PAL can collect in speeds down to 2.4 s/well and can be optimized for HPLC and UHPLC systems collecting into 96- and 384-well plates.

Table I: Gravimetric Studies demonstrating the Precision of the Collect PAL Delivery Mechanism


LEAP Technologies has developed a new state of the art Fraction Collection Instrument, The Collect PAL, capable of meeting the demands of DMPK research groups to acquire much needed data for metabolomic profiling studies. In this development effort the Collect PAL was capable of:

  • Fraction Collection from 0.6–4.1% CV of target weight

  • Delivering the entire stream with a no-loss, no-drip mechanism into specified sealed vials

  • Collection rate down to 2.4 s/well

LEAP Technologies, Inc.

P.O. Box 969, Carrboro, NC 27510

tel. (919)929-8814; fax (919)229-8956

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