# Extractive Electrospray Ionization Mass Spectrometry for Rapid Analysis of Organic and Inorganic Selenium in Honey

## TL;DR

A new method using mass spectrometry quickly detects organic and inorganic selenium in honey, which could help assess selenium intake from dietary sources.

## Contribution

This study introduces a rapid EESI-MS method for detecting and quantifying both organic and inorganic selenium compounds in honey.

## Key findings

- The method successfully identified selenomethionine and sodium selenite in honey samples with high accuracy.
- Calibration curves showed excellent linearity for selenium compounds in the range of 0.5 to 50 µg/L.
- The method achieved detection limits of 2.94 µg/kg for selenomethionine and 5.18 µg/kg for sodium selenite.

## Abstract

Selenium, a crucial trace element for human health, plays a vital role in maintaining well-being. Its insufficiency can cause various diseases, highlighting the need for adequate selenium intake in daily diets. Honey, containing diverse selenium compounds, serves as a beneficial selenium supplement. By leveraging the distinctive physicochemical properties of honey, we employed reactive extractive electrospray ionization mass spectrometry (EESI-MS) to rapidly analyze the presence of both organic selenium (selenomethionine) and inorganic selenium (sodium selenite) in diluted honey samples. We successfully identified selenomethionine (SeMet) and sodium selenite. Calibration curves constructed for SeMet and sodium selenite demonstrated excellent linear relationships within the concentration range of 0.5 to 50 µg/L. The limits of detection (LOD) for SeMet and sodium selenite were determined to be 2.94 µg/kg and 5.18 µg/kg, respectively, while the limits of quantification (LOQ) were 9.52 µg/kg and 17.4 µg/kg, respectively. Furthermore, spiked recoveries ranged from 90.6% to 105%. The average analysis time is 2 min. This study presents a precise, rapid, and convenient method for selenium determination in diluted honey. Given the limited sample size in this preliminary study, future research with larger cohorts is required to validate our findings.