Determination of As in environmental solid matrix

Area of Science:

• Environmental Science
• Analytical Chemistry
• Spectroscopy

Background:

• European environmental guidelines emphasize arsenic (As) concentration in biomasses and complex matrices.
• Accurate As determination is crucial for environmental monitoring and compliance.

Purpose of the Study:

• To identify technical-analytical challenges in As determination using ICP-AES and AAS.
• To evaluate different instrumental spectroscopy techniques for As analysis in environmental solid matrices.

Main Methods:

• Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES).
• Atomic Absorption Spectrometry (AAS) with Deuterium (D2) and Zeeman background correction.
• Electrothermal Atomic Absorption Spectrometry (ETAAS).
• Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
• Analysis of certified reference materials: BCR 141 R (calcareous soil) and IAEA-356 (marine sediment).

Main Results:

• Spectral interference observed with ICP-AES.
• Matrix interference encountered with AAS, particularly ETAAS with D2 correction and HAAS.
• ETAAS with Zeeman background correction at 193.70 nm showed minimal matrix interference.
• ICP-MS and HAAS results confirmed potential for data overestimation and considerable standard deviation, respectively.
• Instrumental reading, not sample mineralization, identified as the critical step for As determination accuracy.

Conclusions:

• ETAAS with Zeeman background correction is a reliable method for As determination in environmental matrices.
• Most other evaluated techniques (ICP-AES, AAS variants, ICP-MS) present specific drawbacks and offer no significant advantage.
• Accurate instrumental reading is paramount for reliable As quantification in complex environmental samples.