Ammonium acetate as a novel buffer for highly selective robust urinary HPLC-ICP-MS arsenic speciation methodology

Area of Science:

• Analytical Chemistry
• Environmental Science
• Toxicology

Background:

• Arsenic speciation is crucial for toxicological assessments.
• Traditional methods for arsenic speciation face challenges with interference and sensitivity.

Purpose of the Study:

• To develop a novel, robust, and interference-free HPLC-ICP-MS methodology for arsenic speciation.
• To accurately quantify six predominant arsenic species in biological samples.

Main Methods:

• High-Performance Liquid Chromatography coupled with Inductively Coupled Plasma Mass Spectrometry (HPLC-ICP-MS).
• Utilized ammonium acetate as a mobile phase additive.
• Optimized chromatographic and detector parameters for enhanced selectivity and sensitivity.

Main Results:

• Successfully separated and quantified six arsenic species: arsenocholine (AC), arsenobetaine (AB), inorganic arsenic (As^III, As^V), and methylated species (DMA, MMA).
• Achieved a reproducible 30-minute chromatogram with high peak area ratio repeatability.
• Demonstrated a robust, selective, and ⁷⁵ArCl⁺ interference-free method.
• Obtained low Limits of Quantitation (LOQs) with acceptable precision and accuracy using certified reference materials.

Conclusions:

• The developed HPLC-ICP-MS method is suitable for accurate arsenic speciation in urine.
• The methodology enables reliable assessment of low-level arsenic exposure (sub ng mL^-1).
• This technique addresses limitations of traditional methods, offering improved analytical performance.