English Product Name

Overview

The Dongxi Analytical AA-7090 is a professionally refurbished, dual-mode atomic absorption spectrometer engineered for high-precision elemental quantification in environmental, clinical, food safety, and industrial quality control laboratories. Designed around the fundamental principle of atomic absorption spectroscopy—where ground-state free atoms in a flame or graphite furnace absorb characteristic radiation from hollow cathode lamps—the AA-7090 integrates flame and graphite furnace atomization in a parallel configuration. This architecture enables rapid method switching without mechanical reconfiguration, minimizing downtime between sample types. Its dual-beam optical path compensates for source intensity drift and lamp aging, ensuring long-term photometric stability. The system employs both deuterium arc (D₂) and transverse alternating-current Zeeman background correction—two complementary techniques validated under ISO 11170 and ASTM D5132 for complex matrix analysis. As a factory-refurbished instrument, each unit undergoes full optical alignment, wavelength calibration verification (using NIST-traceable spectral lines), detector linearity testing, and performance validation per manufacturer specifications prior to shipment.

Key Features

• Parallel Flame-GF Configuration: Independent flame and graphite furnace modules operate concurrently; no manual realignment required when switching atomization modes.
• Transverse AC Zeeman Background Correction: Features a longitudinally oriented, variable-strength magnetic field (0.6–1.1 T in 0.1 T increments) applied perpendicular to the light path—enabling element-specific optimization of Zeeman splitting and background suppression efficiency.
• Horizontal Graphite Furnace Design: Uniform temperature distribution across the entire graphite tube length reduces analyte loss during pyrolysis and improves reproducibility of peak-area integration.
• Dual Gas Path System: Primary carrier gas (Ar or N₂) and programmable auxiliary gas channels allow precise introduction of reactive gases (e.g., O₂ for ashing, H₂ for reduction) to enhance matrix removal and extend graphite tube lifetime.
• 8-Position Encoded Lamp Turret: Fully motorized turret with automatic lamp identification ensures correct lamp selection, current setting, and spectral line alignment—reducing operator error and supporting multi-element workflows.
• Graphite Furnace Visual Monitoring: Integrated digital imaging system provides real-time observation of sample deposition, drying, charring, and atomization stages—critical for method development and troubleshooting.
• Auto-Adjustable Burner Head: Precision stepper-motor-driven vertical positioning enables repeatable alignment of the nebulizer-burner interface within the optical path, maintaining optimal sensitivity across extended operation.

Sample Compatibility & Compliance

The AA-7090 accommodates aqueous solutions, digested biological tissues, acid-leached soils, and diluted petroleum products. It supports direct solid sampling via slurry introduction into the graphite furnace and is compatible with hydride generation accessories for As, Se, Sb, Bi, Te, and Pb. All firmware and control software comply with GLP/GMP documentation requirements, including electronic signature support, audit trail logging, and user-access level management. Background correction algorithms adhere to ISO 8288:2017 (water quality—determination of metals by flame AAS) and USP (heavy metals testing). Optional 21 CFR Part 11-compliant software packages are available for regulated pharmaceutical and clinical labs.

Software & Data Management

Instrument control, method development, and data processing are handled via Dongxi’s proprietary AAWin v5.x platform. The software supports customizable sequence templates, multi-point calibration curves (linear, quadratic, or weighted), QC check standards with pass/fail thresholds, and automated report generation in PDF or CSV formats. Raw signal traces (absorbance vs. time or wavelength) are stored with full metadata—including lamp ID, gas flow profiles, temperature ramp programs, and background correction mode. Data files are structured for seamless import into LIMS environments and include embedded timestamps, operator IDs, and instrument serial numbers for traceability.

Applications

Typical applications include trace metal analysis in drinking water (EPA Method 200.9), soil extractables (EPA Method 6010D), clinical serum Cu/Zn ratios (CLIA guidelines), food product Cd/Pb screening (EU Regulation 1881/2006), and catalyst residue testing in petrochemical feedstocks. The Zeeman mode delivers enhanced selectivity for Fe, Ni, Co, and Cr in high-salt matrices, while D₂ correction remains optimal for low-interference samples requiring maximum throughput.

FAQ

Is this instrument supplied with NIST-traceable calibration verification?
Yes—each refurbished AA-7090 includes a Certificate of Performance Verification referencing NIST SRM 1643e (Trace Elements in Natural Water) and SRM 1640a (Trace Elements in Natural Water).

What maintenance documentation is included?
A complete set of English-language service manuals, optical alignment procedures, and preventative maintenance schedules is provided digitally and on USB.

Can the system be integrated into an existing LIMS?
Yes—the AAWin software supports ASTM E1384-compliant data export protocols and offers optional OPC UA connectivity for enterprise-level integration.

Does the refurbishment include replacement of critical consumables?
All graphite tubes, cuvettes, burner heads, and nebulizers are replaced with OEM-grade components; lamp inventory is verified and replenished as needed.

Is technical support available post-purchase?
Yes—Dongxi-certified engineers provide remote diagnostics, application consultation, and on-site service contracts valid globally.