Determination of Platinum and Palladium in Chelated Systems by GFAAS

Significance of the Topic

Atomic absorption spectrometry using a graphite furnace for trace determination of platinum and palladium in chelated systems plays a crucial role in studying metal–DNA interactions and supporting anti-tumor drug research, especially for cisplatin and related compounds.

Objectives and Study Overview

This application describes two graphite furnace AAS methods to quantify platinum and palladium in chelated complexes. The aims include optimizing furnace parameters, comparing premixed and autosampler calibration, and applying the methods to model systems for stability constant measurements.

Methodology

Graphite furnace AAS was performed on an Agilent SpectrAA 400 with GTA96 atomizer. For platinum, a hollow cathode lamp at 265.0 nm (0.2 nm slit, 5 mA) was used. For palladium, the lamp at 244.8 nm (0.3 nm slit, 5 mA) was employed. Stock solutions (1000 mg/L) were serially diluted in 0.1% v/v HNO₃ to prepare intermediate (10 mg/L) and working standards. Calibration via premixed and autosampler automix was evaluated.

Instrumentation

• Agilent SpectrAA 400 Atomic Absorption Spectrometer
• GTA96 Graphite Tube Atomizer
• Platinum and palladium hollow cathode lamps

Main Results and Discussion

Optimization revealed a platinum ashing range of 800–1000 °C and an atomization temperature of 2700 °C. Palladium showed analogous optimum conditions. Calibration curves from autosampler automix closely matched those from premixed standards, reducing operator error and reagent use. Precision tests with serial dilutions of K₂PtCl₄ yielded recoveries of 95–99% and low relative standard deviations. Analysis of Pt/Pd complexes with bidentate ligands produced yields between 27% and 100%, demonstrating method applicability across various ligands and solvents.

• Ashing region for Pt: 800–1000 °C; atomization: 2700 °C
• Calibration equivalence: premixed vs autosampler automix
• Precision: Pt recoveries of 95–99%
• Complex yields: 57–100% in water and DMSO

Benefits and Practical Applications

These methods enable accurate determination of aquated and chelated platinum and palladium species, supporting studies of metal–DNA binding, pharmaceutical quality control, and environmental trace analysis. Autosampler mixing streamlines workflow and minimizes manual preparation errors.

Future Trends and Applications

Future developments may include further automation, miniaturized furnace designs, coupling with speciation or hyphenated techniques, and advanced data analysis integrations to enhance throughput and data interpretability in complex biological and industrial matrices.

Conclusion

The presented graphite furnace AAS protocols deliver sensitive, reproducible, and efficient measurements of platinum and palladium in chelated systems. Optimized furnace settings and calibration strategies provide a robust platform for research and quality assurance applications.

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