Micro Fraction Collection (optional)
Injection Mechanism

The WPS-3000 Well Plate Autosampler has been specifically designed to provide unattended sample throughput, combined with superior reproducible injections, of even the smallest samples volumes. It is the ideal solution for chromatography users looking to work with the highest injection precision at nano/cap/micro flow rates.
The sample rack handles up to three well plates (96 or 384 wells—sealed or unsealed) or sample vial trays, or combinations thereof. Flawlessly exchange sample plates or use priority samples during a run sequence using the Well Plate Autosampler. Applying the cooling option, the sample rack is completely sealed, opening only during the injection cycle, for optimal storage of thermo-labile samples. The optional Micro Fraction Collection allows for automated off-line multidimensional LC (MDLC) with fully automated collection and reinjection of over 1000 samples without any manual handling.

• Three well plate capacity (up to 1152 samples)
• Micro Fraction Collection (optional)
• Patented sample thermostatting, 4–45 °C, 22 °C below ambient
• Sealed sample compartment for outstanding temperature stability
• Allows injections of thermo-labile proteins
• Dual-needle injection principle
• Large injection range: 20 nL to 100 µL
• Unmatched injection precision
• Lowest carryover: typically <0.01%
• Biocompatible option

Micro Fraction Collection

With the new Micro Fraction Collection option for the pulled loop WPS-3000 Autosampler, injection, fractionation, and reinjection can all be performed on one single, fully automated system. Taking full advantage of the three well plate capacity, the system is capable of fractionating and reinjecting over a 1000 samples, without the need for any manual handling.

UltiMate™ 3000 Nano, Capillary, and Micro LC systems with the Micro Fraction Collection option installed offer fully automated off-line Multidimensional Liquid Chromatography, without being tied to a specific method or flow rate range. Off-line MDLC offers several advantages over other MDLC methods, such as:

• Higher flexibility with respect to column dimensions and mobile phase selections
• Easy method development
• Optimization of each separation dimension
• Ability to perform multiple analyses of the fractionated sample, even with different methods

In combination with the Extended Fraction Collection capabilities of the Chromeleon®  Chromatography Management Software, set up, system control, reviewing, and data reporting are straight-forward and easily performed.

Injection Mechanism

Using the dual-needle principle, the vial septum ot the well seal is pierced by the stainless steel outer needle. The sampler guides the sampling needle, made of a fused silica capillary, through the piercing needle down to the bottom of the sample carrier. Easily program the sample needle height to match sample vial or well depth. Injections of minute sample volumes, with virtually zero sample loss—1 µL injection per 1 µL sample—are performed using the µL-pickup routine. This routine is of particular importance when injecting protein samples that cannot be diluted without the risk of protein loss or alteration.

In order to guarantee the best chromatographic performance when injecting volumes in the ranges of 20 nL–250 µL, the WPS-3000 works with a pulled loop injection mechanism. This dramatically reduces delay times in the system and provides more accurate and precise gradient profiles, reduces peak broadening and allows for better peak resolution.