Chromatographic Determination of Total Selenium in Biofortified Allium   sp. following Piazselenol Formation and Micro-Solid-Phase Extraction

• Published in: Molecules (Basel, Switzerland) Vol. 26; no. 21; p. 6730
• Main Authors: Bosca, Bogdan M, Mot, Augustin C
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 06-11-2021; MDPI
• Subjects: Allium; Allium - chemistry; Azoles - chemistry; Calibration; Chromatography; Diamines; Drug Compounding; Ethylenediaminetetraacetic acids; High performance liquid chromatography; Hydrochloric acid; Hydrogen peroxide; Hydroxylamine; Liquid chromatography; Methods; micro-solid-phase extraction; Molecular Structure; Nitric acid; Open systems; Organoselenium Compounds - chemistry; Phenylenediamine; piazselenol; Reaction time; Reagents; Reference materials; Scientific imaging; Selenium; Selenium - analysis; Solid Phase Microextraction; Solid phases; Temperature effects; United States > US; Germany; selenium; piazselenol; micro-solid-phase extraction; Allium
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules26216730

Herein, a method based on selective piazselenol formation is applied for total selenium determination in biofortified
species. Piazselenol is formed by reacting Se(IV) with an aromatic diamine, namely 4-nitro-1,2-phenylenediamine, in acidic medium. Samples were digested in a nitric acid/hydrogen peroxide open system, followed by selenate reduction in hydrochloric acid. Reaction conditions were optimized in terms of pH, temperature, reaction time, and other auxiliary reagents for interference removal, namely, EDTA and hydroxylamine. For the extraction of the selectively formed 4-nitro-piazselenol, micro-solid-phase extraction (μSPE) was applied, and the analysis and detection of the corresponding complex was performed by HPLC coupled with DAD. An external standard calibration curve was developed (R
= 0.9994) with good sensitivity, and was used to calculate the total selenium content from several
plants material, with good intermediate precision (RSD% < 16%). The accuracy of the method was evaluated using both, a comparison with an accepted reference method from our previously published data, as well as three certified reference material with recoveries between 84-126%. The limit of detection was determined to be 0.35 μg/g (in solids) and 1.1 μg/L (in solution), while the limit of quantification was 1.07 μg/g and 3.4 μg/L (in solution). Using the proposed method, selenium content can be quickly and accurately determined in several types of samples. In addition, this study present experimental conditions for overcoming the interferences that might be encountered in selenium determination using piazselenol.