TS-FF-AAS and multivariate calibration: A proposition for sewage sludge slurry sample analyses

Area of Science:

• Environmental Chemistry
• Analytical Chemistry

Background:

• Sewage sludge analysis requires accurate heavy metal quantification.
• Traditional methods may lack sensitivity for trace contaminants.

Purpose of the Study:

• To develop and validate a sensitive method for cadmium (Cd) and lead (Pb) determination in sewage sludge.
• To improve detection and quantification limits compared to conventional techniques.

Main Methods:

• Utilized thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS).
• Employed a nickel (Ni) tube atomizer with an air/acetylene flame.
• Applied two partial least squares (PLS) multivariate calibration models using total peak profiles.

Main Results:

• Successfully determined Cd and Pb concentrations in sewage sludge slurry samples.
• Achieved low limits of detection (LOD) and quantification (LOQ): Cd (0.2 µg kg⁻¹, 0.7 µg kg⁻¹) and Pb (8 µg kg⁻¹, 26 µg kg⁻¹).
• Demonstrated a threefold improvement in LOD/LOQ compared to linear calibration with aqueous standards.

Conclusions:

• The proposed TS-FF-AAS methodology with PLS calibration offers enhanced sensitivity for Cd and Pb analysis in complex matrices like sewage sludge.
• This method provides a valuable tool for environmental monitoring and sludge management.