Determination of selenium compounds by HPLC with ICP-MS or FAAS as selenium-specific detector

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biochemistry

Background:

• Selenium speciation is critical for understanding its biological roles and environmental fate.
• Accurate quantification of different selenium forms is essential for toxicological and nutritional studies.

Purpose of the Study:

• To develop and optimize a high-performance liquid chromatography (HPLC) method for separating four key selenium species.
• To couple HPLC with sensitive detection techniques, including flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS), for selenium analysis.

Main Methods:

• HPLC separation using an anion-exchange column with an ammonium citrate mobile phase.
• On-line detection utilizing FAAS and ICP-MS.
• Optimization of ICP-MS detection by employing an ultrasonic nebulizer (USN) to enhance signal intensity.

Main Results:

• Successful separation of selenious acid, selenic acid, trimethylselenonium ion (TMSe), and selenomethionine (SeMet) within 8 minutes.
• HPLC-FAAS achieved detection limits of approximately 1 mg/L for all species.
• HPLC-USN-ICP-MS demonstrated significantly improved detection limits, down to 0.07-0.34 µg/L, with substantial signal enhancement using the USN.

Conclusions:

• The developed HPLC method provides efficient separation of major selenium species.
• Coupling HPLC with USN-ICP-MS offers a highly sensitive and effective approach for selenium speciation analysis.
• This method is valuable for accurate selenium determination in various matrices.