Preparation, homogeneity and stability studies of a candidate LRM for Se speciation

Abstract

A laboratory reference material (LRM) was prepared from Brazil nuts (Bertholletia excelsa) for quality control (QC) purposes of selenium speciation. The preparation of this LRM led through the usual operation steps applied during routine reference material production from biota samples-preparation of the raw material, homogenisation, storage design, checking of homogeneity, microbiological status and possible irradiation effects, and monitoring the species stability vs time at different storage temperatures. The selenium speciation studies to check species stability were carried out on a HPLC-UV-HG-AFS measurement set-up. Special attention was paid to the correct identification of selenium species by applying independent HPLC separation techniques (ion-pairing and anion-exchange chromatography). The concentration of selenomethionine (SeMet) and total Se content were quantified (79.9 microg g(-1) (calculated as Se) and 82.9 microg g(-1), respectively). The homogeneity and stability of this candidate reference material passed the relevant tests recommended by Bureau Communautaire de Référence (BCR).

Effects of Brazil nut consumption on selenium status and cognitive performance in older adults with mild cognitive impairment: a randomized controlled pilot trial

“…Only one nut of this richest food source of selenium contributed with 288.75 µg of selenium daily, increasing selenium intake to more than the recommended levels (55 µg/day), but not exceeding the tolerable upper intake level (400 µg/day) [45]. Selenium in Brazil nuts is found in selenomethionine and selenocysteine species, and studies show that selenomethionine concentration ranges from 75 to 90 % [46,47]. Despite high selenium content in Brazil nuts, no participants complained of symptoms associated with selenosis, as observed by Lemire et al [48].…”

Fate of selenium species in sesame seeds during simulated bakery process

“…The usual analytical practice is based on proteolytic enzymes as tools of this process (Bodó et al, 2003;Gilon, Astruc, Astruc, & Potin-Gautier, 1995;Huerta et al, 2003;Kannamkumarath et al, 2002;Yasumoto et al, 1988). One-step enzymatic digestion with the help of two commercially available proteolytic enzymes, pronase E and protease XIV was applied (Bodó et al, 2003;Gilon et al, 1995). The ground and de-fatted sample (350 mg) was placed in a 15 mL polyethylene vial followed by the addition of 30 mg enzyme dissolved in 4.5 mL 50 mM potassium phosphate buffer (pH 7.4).…”

“…The Se-speciation analysis was carried out with the help of a high performance liquid chromatography-UV photochemical digestion-hydride generation-atomic fluorescence detection system (HPLC-UV-HG-AFS) described elsewhere (Bodó et al, 2003;Ipolyi, Corns, Stockwell, & Fodor, 2001) and only modifications are listed here. The separation was performed on a silica-based strong cationexchange column (Ionospher 5C, Varian BV, Middelburg, The Netherlands) and on a polystyrene-divinylbenzenebased anion-exchange column (Hamilton PRP X-100, Reno, NV, USA).…”

“…The separation was performed on a silica-based strong cationexchange column (Ionospher 5C, Varian BV, Middelburg, The Netherlands) and on a polystyrene-divinylbenzenebased anion-exchange column (Hamilton PRP X-100, Reno, NV, USA). The cationic separation parameters were optimised based on the study of Larsen, Sloth, Hansen, and Moesgaard (2003), while the parameters of the anionic system were adopted from Bodó et al (2003); both cationic and anionic conditions are presented in Table 1. An atomic fluorescence detector, PSA 10.033 (PSA Excalibur, Orpington, Kent, UK) was used.…”

“…spirulina (Cases et al, 2002) and some edible plant species such as Allium sp. (Ge et al, 1996;McSheehy et al, 2000;Shah, Kannamkumarath, Wuilloud, Wuilloud, & Caruso, 2004) and Brazil nuts (Bodó et al, 2003;Kannamkumarath, Wrobel, Vonderheide, & Caruso, 2002) have been extensively studied from the outstanding Se-enrichment capacity point of view. Food materials with average or low Se-contentoften the most consumed foodstuffs -are usually not aimed, with some exceptions of wheat (De la Calle- Gunti-ñ as et al, 1997;Huerta, Reyes, Marchante-Gayó n, Fernández Sánchez, & Sanz-Medel, 2003) and soybean (Yasumoto, Suzuki, & Yoshida, 1988) samples.…”