Selenium inorganic speciation in beers using MSFIA-HG-AFS system after multivariate optimization.

Area of Science:

• Analytical Chemistry
• Environmental Science

Background:

• Selenium speciation is crucial for understanding its bioavailability and toxicity.
• Existing methods for selenium speciation can be complex and time-consuming.
• Beer is a common dietary source of selenium, necessitating accurate analytical methods.

Purpose of the Study:

• To develop and validate a sensitive analytical method for inorganic selenium chemical speciation in beer.
• To optimize the hydride generation conditions for enhanced sensitivity.
• To determine the concentrations of different inorganic selenium species in Spanish beer samples.

Main Methods:

• Multisyringe flow injection analysis (MSFIA) coupled to hydride generation atomic fluorescence spectrometry (HG-AFS).
• Doehlert design for optimization of hydride generation parameters (NaBH4 and HCl concentrations).
• Analysis of standard reference materials and application of addition and recovery tests for validation.

Main Results:

• Achieved limits of quantification of 0.07 µg L⁻¹ for total inorganic Se and 0.08 µg L⁻¹ for Se(IV).
• The method demonstrated high accuracy and precision.
• Determined Se(IV), total inorganic Se, and Se(VI) concentrations in eight Spanish beer samples, with ranges observed for Se(IV) (<0.08 - 0.46 µg L⁻¹), total inorganic Se (0.47 - 3.04 µg L⁻¹), and Se(VI) (0.06 - 3.00 µg L⁻¹).

Conclusions:

• The proposed MSFIA-HG-AFS method is accurate, precise, and sensitive for selenium speciation in beer.
• This method provides a reliable tool for assessing inorganic selenium content in beverages.
• The findings contribute to understanding selenium levels in commonly consumed products.