Autosampler 3950 HPLC

The Autosampler 3950 can inject from up to 768 positions when equipped with microtiter plates (either high or low formats) or from up to 96 standard 2 ml sample vials. Sample carryover is significantly minimized thanks to a highly-effective interior and exterior needle wash procedure. This autosampler is also fast and flexible: one complete sample injection cycle takes less than one minute, including needle wash. Three different injection modes are supported; “full loop filling” (highest precision and reproducibility), “partial loop filling” (variable volumes, e.g. for dilution series) and “µl pickup” (loss-free injection of extremely small sample volumes), allowing the user to optimize sample usage. The headspace pressure function prevents bubbles from forming in the vial during sample uptake. Precolumn derivatization is supported.

For high-pressure injections of up to 1000 bar, the autosampler is equipped with a so-called ILD™ valve (Intermediate Loop Decompression). This valve consists of a rotor-stator combination and includes a central port for depressurizing. For high pressure applications, the sample loop is depressurized prior to receiving the sample. This way, the sample is not diluted with solvent. Because the valve is switched extremely fast, pressure spikes are reduced. Analyses are more precise and wear of the column is reduced.

Key features:

-         1000 bar

-         0.1-5000 µl injection volume

-         PASATM (pressure-assisted sample aspiration) 

-         ILD (intermediate loop decompression)

-         Cooling/heating version (4-40°C)

-         With sample tray cooling (4 - 22°C) and biocompatible sample path.

Different types of HPLC Autosamplers 3950:

-        Standard version of a fast and very versatile analytical HPLC autosampler, 1000 bar, 0.1- 5000 µl injection volume.

-        Cooling/heating version of a fast and very versatile analytical HPLC autosampler, 1000 bar, 0.1-5000 µl injection volume.

-        Analytical HPLC autosampler with biocompatible flow path.

-        Analytical HPLC autosampler with biocompatible flow path and sample cooling

Sample injection

Sample capacity

microtiter plates for max. 768 samples or sample plates for max. 96 vials

Vial/plate dimensions

Max. plate/vial height: 47 mm (incl. septa or capmat)

Injection volume range

0.1–5000 µl programmable

Sample loop

10 µl standard

Dispenser syringe

250 µl

Headspace pressure

built-in compressor, only for vials with septum

Switching time inj. valve

< 100 ms

Piercing needle precision

± 0.6 mm

Sample tray cooling



Vial detection

missing vial/well plate detection by sensor

Needle wash

programmable: wash between injections and wash between vials

Wetted materials

Stainless steel (SS316), Tefzel®, Vespel®, glass, Teflon® (PTFE). 

Analytical performance

Injection modes

full loop, partial loopfill and µl pickup mode; PASA™ (pressure-assisted sample aspiration)

Injection precision

RSD (Relative Standard Deviation):

full loop injection: <0.3%

partial loop injection at an injection volume >10 µl: <0.5%

microliter pickup injection at an injection volume >10 µl: <1.0%

Injection volumes

full loop: max. 5000 µl 
partial loop: max. 2500 µl (50% loop volume)
µl pickup: max. 2455 µl (50% loop volume - 1,5x needle volume)

1 µl increment for all injection modes

Sample carryover

< 0.05 % with programmable needle wash

Injections per vial

max. 9 injections

Injection cycle time

minimum 7 s from the same vial, 14 s from different vials;

< 60 s for ≤ 100 µl sample injection in all injection modes, incl. 300 µl needle wash

Analysis time

max. 9 h, 59 min, 59 s



2 programmable TTL inputs (next injection, freeze, stop)


1 programmable relay output (inject marker, auxiliary, alarm)


Ethernet (LAN)

Technical parameters

Ambient conditions

temperature range: 4–40 °C; 39.2–104 °F

air humidity: below 90 % humidity (non condensing)


Power supply

90–230 V AC ± 10 %; 50–60 Hz; 200 VA


300 x 360 x 510 mm (W x H x D)


19.0 kg