AS-500 Graphite Furnace Autosampler

Overview

The AS-500 Graphite Furnace Autosampler is an engineered precision liquid handling system designed exclusively for integration with atomic absorption spectrometers (AAS) equipped with electrothermal graphite furnace atomizers. It operates on a syringe-driven positive-displacement principle, delivering sub-microliter volumetric accuracy and positional repeatability critical for trace elemental analysis in complex matrices. By eliminating manual pipetting, human error, and inter-operator variability, the AS-500 ensures high reproducibility (RSD < 1.0%) across replicate analyses—meeting stringent requirements for regulatory compliance in environmental testing, clinical toxicology, food safety, and pharmaceutical quality control laboratories.

Key Features

• 70-position sample rack accommodating standard 13 mm × 100 mm borosilicate glass vials, plus six dedicated 25 mL reservoir positions for stock standards, blanks, and chemical modifiers (e.g., Pd-Mg nitrate, NH₄H₂PO₄)
• Computer-controlled micro-syringe delivery with ±0.1 µL volumetric accuracy and fixed injection point targeting within the graphite tube center—ensuring consistent thermal history and atomization efficiency
• Automated calibration curve generation: dilutes a single stock standard to produce up to 20 discrete concentration levels directly into the graphite furnace, minimizing standard consumption and cross-contamination risk
• Programmable multi-step protocols including sequential aspiration of sample, modifier, and matrix modifier; configurable rinse cycles between injections using deionized water or dilute acid
• Unattended operation capability: full sequence execution—including sample loading, dilution, injection, furnace heating initiation, and post-injection cleaning—without operator intervention
• Maximum per-injection volume of 70 µL; up to 99 repeated injections per sample position for method validation or signal averaging
• Optional integrated concentration/dilution module enabling offline pre-concentration (e.g., chelation-based enrichment) or matrix-matched dilution prior to furnace introduction

Sample Compatibility & Compliance

The AS-500 handles aqueous, acidic (up to 10% HNO₃ or HCl), and organic-aqueous mixtures compatible with standard graphite furnace AAS methods. All wetted components—including syringe barrel, needle, and fluidic pathways—are constructed from chemically inert materials (e.g., PTFE, sapphire, and fused silica) to prevent adsorption or leaching of analytes such as Pb, Cd, As, and Se. The system supports method documentation and audit trails aligned with GLP and ISO/IEC 17025 laboratory accreditation frameworks. While not FDA 21 CFR Part 11–certified out-of-the-box, its software architecture permits configuration of electronic signatures, user access levels, and immutable data logging when deployed with compliant LIMS or instrument control platforms.

Software & Data Management

Controlled via Windows-based application with intuitive graphical interface, the AS-500 software guides users through method setup using context-sensitive prompts and real-time status feedback. Each method file stores complete protocol parameters—including aspiration volumes, dwell times, rinse sequences, and modifier addition timing—as structured XML metadata. Raw injection logs (timestamp, volume, position ID, error codes) are exported in CSV format for traceability. Integration with Thermo Scientific iCE 3500, PerkinElmer PinAAcle 900Z, or Shimadzu AA-7000 series is achieved through standardized RS-232 or USB virtual COM port communication, enabling synchronized furnace temperature ramp triggering upon injection completion.

Applications

• Regulatory monitoring of heavy metals in drinking water (EPA Method 200.9, ISO 11171)
• Quantification of essential and toxic elements in biological fluids (serum, urine) per CLIA and CAP guidelines
• Analysis of residual catalysts (e.g., Pd, Rh) in active pharmaceutical ingredients (APIs) per ICH Q2(R2)
• Determination of trace nutrients (Fe, Zn, Cu) in fortified foods and infant formula (AOAC 984.27)
• Speciation-unresolved total element screening in soil extracts and sediment digests (ISO 17294-2)

FAQ

What is the minimum detectable injection volume?
The AS-500 achieves reliable aspiration and dispensing down to 0.1 µL using a calibrated gas-tight syringe with pressure-compensated plunger drive.
Can the AS-500 be used with non-graphite-furnace AAS systems?
No—it is mechanically and electronically optimized for electrothermal atomization only; it lacks nebulizer interface hardware or spray chamber compatibility.
Is method validation support included?
Yes—the software includes built-in tools for RSD calculation across replicates, carryover assessment via blank-after-standard sequences, and linearity evaluation of generated calibration curves.
Does the system require external compressed air or vacuum sources?
No—all fluid handling is driven by the internal stepper-motor–actuated syringe; only standard AC power and serial/USB connectivity are required.
How is carryover minimized between high-concentration and low-concentration samples?
Three-stage automated rinsing (sample loop, needle exterior, and interior capillary) with configurable rinse solvent volume and dwell time ensures <0.05% carryover for analytes like Cd and Pb.