High Capacity HPLC Autosampler Low Carryover For Food Safety Testing

Maximize sample throughput and data integrity with our flow-through autosampler, designed for high-sensitivity pesticide residue, veterinary, and mycotoxin analysis. It delivers injection precision better than 0.3% RSD even at 0.1 µL volumes, with a verified carryover specification of less than 0.003%. The thermostat-controlled tray protects thermally labile samples and maintains chain of custody. An advanced needle wash routine and programmable injection sequences, including air gap sandwiching and feed injection, make it the first choice for food safety labs operating under ISO 17025 and SANTE guidelines.

Carryover is the number-one enemy of trace-level analysis. In pesticide residue labs, a single high-concentration control sample can leave fuberidazole or chlorpyrifos on the needle seat, producing a false positive in the next blank injection. Sample degradation on the bench causes inaccurate results. Manual sample prep mistakes—missed vials, transposition errors, mislabeling—cost hours of re-analysis. Additionally, validation protocols like SANTE/11312/2021 demand proof of carryover ≤0.1% for each analyte, and a poorly designed autosampler cannot meet this goal.

We engineered the autosampler with a true flow-through needle that is continuously flushed by mobile phase between runs. The needle and seat are fabricated from passivated stainless steel with an electropolished finish (Ra<0.2 µm) to eliminate adsorption sites. Four programmable wash solvents are available; the system can rinse the external needle surface with strong organic and then water, sequentially. The sample tray holds 216 standard 2-mL vials, or 384-well plates via an adaptor, and can be set to 4°C to 40°C. Pre-injection air gaps prevent sample dispersion. Full barcode reading and LIMS integration eliminate manual data entry, so your run log is auditable from vial scan to final report.

• Multi-residue pesticide analysis in fruits and vegetables (QuEChERS extracts)

• Veterinary residues in meat/seafood

• Mycotoxins in cereals, nuts, and spices

• Trace nitrosamines in substances

• Drinking water organic contaminant monitoring

• Clinical TDM (therapeutic monitoring)

The robotic arm picks a vial, reads the barcode, then draws the sample into the sample loop or needle seat. A high-precision syringe drive meters the volume. Before injection, a small air gap seals the sample plug. The needle then docks into the high-pressure injection port; the valve switches to allow mobile phase to sweep the plug into the column. After injection, the needle immediately undergoes an internal flush while the external surface is washed in a separate station, all before the next vial is picked, completely decoupling sample from sample.

Calculate your daily sample load: a 216-vial capacity supports roughly 200 injections/day on a 10-min method. If you run overnight batches, a second tray can be pre-loaded on a swap cart for 5-min changeover. Choose the wash station solvents based on your analytes: use DMSO or DMF for tough-to-remove compounds. For wines or high-sugar matrices, include a water wash step to prevent sucrose crystallization. Request a demo with your worst-case analyte to verify carry-over; we will provide a test protocol and data before purchase.

Q1: Can I use 96-well plates directly?
A: Yes, with an optional plate handler. The system holds two deep-well plates or four microtiter plates, maintaining temperature control throughout.

Q2: How do you prevent needle clogging from particulate samples?
A: We recommend filtering all samples to 0.2 µm. The system also includes a pressure watchdog that aborts the injection if back-pressure exceeds a user-defined maximum, preventing column damage.

Q3: How long does it take to wash the needle?
A: A standard double-wash program takes 25 seconds. Needle wash occurs during the chromatographic run, so it adds zero extra cycle time.

Q4: Is dead volume minimized for fast UHPLC?
A: Yes, the entire flow path from needle tip to column inlet has a dispersion volume under 5 µL with a 0.12 mm i.d. tubing kit, preserving UHPLC peak shape.