title: Evaluation of selenium species in selenium-enriched pakchoi (Brassica chinensis Jusl var parachinensis (Bailey) Tsen & Lee) using mixed ion-pair reversed phase HPLC-ICP-MS.
abstract: HPLC-ICP-MS based on ion-paired reversed phase chromatography for the selenium speciation using the mixture of 1-butanesulfonic acid (BA) and trifluoroacetic acid (TFA) as the mixed ion-pairing reagents was developed and applied to selenium-enriched pakchoi (Brassica chinensis Jusl var parachinensis (Bailey) Tsen & Lee). Several conditions of ion-paired reversed phase HPLC-ICP-MS, such as pH of the mobile phase, concentration of ion pairing reagents, types and length of analytical column, and flow rate of the mobile phase, were optimised for five selenium species; selenate (Se(VI)), Selenite (se(IV)), selenocysteine (SeC), Se-methylselenocysteine (SeMC) and selenomethionine (SeM). The results showed that the optimum conditions for pH, BA and TFA condition, type of separating column and flow rate, were 4.5, 8mM, 4mM, C18 (250 mm length × 4.6mm I.D) and 1.2 mL min(-1), respectively. These conditions archived separation of the organic selenium species. The limits of detection (LOD) and quantitation (LOQ) of each selenium species were lower than 5 and 16 ng Se mL(-1), respectively. Furthermore, the recoveries of most selenium species were good, except for SeC. In this research, selenium-enriched pakchoi was cultivated by supplementing inorganic selenium from selenate into sand. The result showed that inorganic selenium, SeMC, SeM and several unknown species were found in selenium-enriched pakchoi sprouts by using the proposed method. Thereby, the biotransformation of selenate in pakchoi was similar to other Brassicaceae plants such as kale and broccoli.
authors.affiliation: Department of Chemistry and Center of Excellence for Innovation in Chemistry (PERCH-CIC), Faculty of Science, Mahasarakham University, Kantarawichai, Maha Sarakham 44150, Thailand.
authors.forename: Witphon
authors.initials: W
authors.lastname: Thosaikham
authors.forename: Kritsana
authors.initials: K
authors.lastname: Jitmanee
authors.forename: Rossukon
authors.initials: R
authors.lastname: Sittipout
authors.forename: Sarunya
authors.initials: S
authors.lastname: Maneetong
authors.forename: Anut
authors.initials: A
authors.lastname: Chantiratikul
authors.forename: Piyanete
authors.initials: P
authors.lastname: Chantiratikul
mesh_terms: D017738:Alkanesulfonic Acids / Q000737:chemistry; D001937:Brassica / Q000737:chemistry* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry; D010936:Plant Extracts / Q000737:chemistry; D064586:Selenic Acid / Q000032:analysis / Q000302:isolation & purification; D020887:Selenious Acid / Q000032:analysis / Q000302:isolation & purification; D018036:Selenium Compounds / Q000032:analysis / Q000737:chemistry* / Q000302:isolation & purification; D017279:Selenocysteine / Q000031:analogs & derivatives / Q000032:analysis / Q000302:isolation & purification; D012645:Selenomethionine / Q000032:analysis / Q000302:isolation & purification
chemical_list: D017738:Alkanesulfonic Acids; D010936:Plant Extracts; D018036:Selenium Compounds; D017279:Selenocysteine; C036011:1-butanesulfonic acid; D012645:Selenomethionine; D020887:Selenious Acid; D064586:Selenic Acid; C002979:selenomethylselenocysteine
keywords: Brassicaceae plants; Ion-paired reversed phase HPLC–ICP-MS; Pakchoi (Brassica chinensis Jusl var parachinensis (Bailey) Tsen & Lee); Se-enriched pakchoi; Selenium speciation