Dongxifenxi AA-7000 Used Flame and Graphite Furnace Atomic Absorption Spectrometer

Overview

The Dongxifenxi AA-7000 is a dual-mode atomic absorption spectrometer engineered for trace metal quantification in liquid samples across environmental, pharmaceutical, food safety, and industrial quality control laboratories. It operates on the fundamental principle of atomic absorption spectroscopy: ground-state free atoms in a flame or graphite furnace absorb characteristic radiation from hollow cathode lamps (HCLs), with absorbance directly proportional to analyte concentration per Beer–Lambert law. The instrument integrates both flame atomization (for ppm-level analysis of elements such as Ca, Mg, Na, K, Fe, Cu, Zn) and electrothermal graphite furnace atomization (for sub-pg detection of Cd, Pb, As, Se, Cr, Ni). Its dual-beam optical architecture compensates for source intensity drift and lamp aging, ensuring long-term baseline stability and measurement reproducibility without manual recalibration between runs.

Key Features

• Dual-atomization capability: Switchable flame and graphite furnace modes—no hardware reconfiguration required; furnace module includes integrated temperature programming with up to 30-step ramping profiles.
• Automatic background correction: Combines deuterium arc and high-frequency modulated hollow cathode lamp methods for accurate correction of molecular absorption and light scattering in complex matrices (e.g., wastewater digests, biological tissues).
• Solid-state detector system: High quantum efficiency photodiode array with 2048-pixel resolution enables precise spectral isolation at 0.2 nm nominal bandwidth, minimizing interferences from adjacent emission lines.
• Refurbishment protocol: Each unit undergoes full OEM-equivalent refurbishment—including optical alignment verification, burner head cleaning/replacement, graphite tube lifetime assessment, HCL output calibration, and pneumatic system leak testing—prior to shipment.
• Robust mechanical design: Stainless-steel optical bench with thermal mass stabilization minimizes vibration sensitivity and ambient temperature drift during extended furnace runs.

Sample Compatibility & Compliance

The AA-7000 accommodates aqueous solutions, acid-digested environmental solids (EPA Method 200.2, 3050B), biological digestates (AOAC 999.10), and food extracts (ISO 6869:2000). Sample introduction supports autosampler integration (optional AS-7000), programmable dilution, and matrix-matched standard addition calibration. All firmware and software comply with GLP requirements per ISO/IEC 17025:2017 Annex A.5 and support 21 CFR Part 11–compliant electronic signatures when paired with validated AAWin v3.x configuration (audit trail, user access levels, and operation logging enabled by default).

Software & Data Management

AAWin v3.x provides intuitive method setup, real-time signal visualization, peak area/integration optimization, and multi-point calibration curve fitting (linear, quadratic, weighted least-squares). Raw data files (.aaw) are stored with embedded metadata: lamp ID, slit width, integration time, furnace temperature program, and operator ID. Export formats include CSV, PDF reports (with digital signature), and XML for LIMS integration. The software maintains full audit trail logs covering method edits, result modifications, and instrument parameter changes—retained for ≥18 months per internal validation protocol.

Applications

• Environmental labs: Quantification of heavy metals in drinking water (EPA 7000B), soil leachates (TCLP), and airborne particulate filters (NIOSH 7300).
• Pharmaceutical QC: Residual catalyst analysis (Pd, Pt, Rh) in APIs per ICH Q2(R2); elemental impurities screening per USP /.
• Food safety: Lead and cadmium in rice, infant formula, and seafood per GB 5009.12–2023 and EU Commission Regulation (EU) No 2023/915.
• Academic research: Speciation studies via hydride generation coupling (As, Sb, Bi) and direct solid sampling (via optional laser ablation interface).

FAQ

Is this unit covered by a warranty?
Yes—each refurbished AA-7000 carries a 12-month limited parts-and-labor warranty covering defects in materials and workmanship under normal laboratory use.
Can the instrument be validated for GMP environments?
Yes—full IQ/OQ documentation packages are available upon request, including test protocols aligned with ASTM E2656–18 and manufacturer-recommended acceptance criteria.
What consumables are included with purchase?
Standard delivery includes one set of quartz cuvettes, two graphite tubes (pyrolytically coated), five HCLs (Fe, Cu, Zn, Cd, Pb), and AAWin v3.x installation media with activation license.
Does it support third-party autosamplers?
It natively communicates with Dongxifenxi AS-7000; RS-232 and USB interfaces allow integration with select CETAC, GBC, or PerkinElmer autosamplers via custom serial command mapping.
How is performance verified prior to shipment?
Each unit passes a full performance qualification: detection limit verification (3σ of blank), precision test (RSD ≤ 1.5% for 10 replicate injections), linearity check (r² ≥ 0.999 over 3 orders of magnitude), and background correction accuracy assessment using certified reference materials (NIST SRM 1643e, 1640a).