Speciation analysis of selenium in garlic by two-dimensional high-performance liquid chromatography with parallel inductively coupled plasma mass spectrometric and electrospray tandem mass spectrometric detection

• Published in: Analytica chimica acta 2000-09, Vol.421 (2), p.147-153
• Main Authors: McSheehy, Shona, Yang, Wenjie, Pannier, Florence, Szpunar, Joanna, Łobiński, Ryszard, Auger, Jacques, Potin-Gautier, Martine
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Biological and medical sciences; Chemical Sciences; ES MS/MS; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Garlic; General pharmacology; HPLC; ICP MS; Medical sciences; Pharmacognosy. Homeopathy. Health food; Pharmacology. Drug treatments; Speciation
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/S0003-2670(00)01039-4

Speciation of selenium in garlic harvested in naturally seleniferous soil was investigated. The sample was leached with water and the aqueous extract was fractionated by preparative size-exclusion chromatography. Selenium was found in only one (low-molecular mass) fraction. The chromatographic purity of the fraction was verified by reversed-phase chromatography with inductively coupled mass spectrometric detection. Again, one major signal accounting for more than 95% of the total selenium was observed. The heartcut fraction containing this compound produced an intense peak in an electrospray mass spectrum with the selenium pattern centered at m/z 313 ( 80Se). Protonated molecular ions corresponding to the four Se isotopes gave rich fragmentation patterns by collision induced dissociation that allowed the identification of the selenium species to be γ-glutamyl-Se-methylselenocysteine without the need for an authentic standard.