069: Enhancing Selenium Detection in Food: Improving Sensitivity With ICP-OES and Hydride Generation

Introduction

The United States Food and Drug Administration (FDA) mandates that infant formulas contain selenium (Se) within established minimum and maximum levels. Hydride generation is a widely used gas-phase sample introduction technique in Atomic Emission Spectroscopy, particularly for elements that form stable hydrides. Selenium forms hydrogen selenide in the presence of acidic media and a reductant solution. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) is a highly sensitive method ideal for analyzing mineral elements in food samples. This study evaluated Se concentrations in ten infant formulas using a Multimode Sample Introduction System (MSIS) for hydride generation with ICP-OES.

Methods

Ten infant formulas were purchased from a local supermarket and digested using a microwave digestion system, which converts solid samples into liquid form through heat, pressure, and acidification. The digested samples were analyzed using MSIS-ICP-OES.

Results

Selenium was detected in all samples, with concentrations ranging from 0.20 to 0.43 ppm. The use of hydride generation over conventional nebulization significantly improved sensitivity, enhancing detection limits and precision for accurate Se determination in infant formulas.

Significance

This study demonstrates a sensitive and precise method for measuring selenium in infant formula, ensuring compliance with FDA standards. The findings support improved quality control and nutritional safety in formula production.

Author: Ana Garcia-Gonzalez