Development and application of a HPLC-ICP-MS method to determine selenium speciation in muscle of pigs treated with different selenium supplements.

Dietary selenium deficiency is recognized as a global problem. Pork is the most widely consumed meat throughout the world and an important source of selenium for humans. In this study, a reliable approach was developed for analyzing selenium and its speciation in the muscles of pigs after different selenium treatments. The selenium source deposition efficiency was ranked as: selenomethionine > methylselenocysteine > selenite, and the muscle selenium content had a dose effect with selenomethionine supplementation. In total, four species of selenium were detected in the muscles of pigs and the distributions of these selenium species were greatly affected by the dietary selenium supplementation forms and levels. Selenomethionine (>70% of total selenium) and selenocystine (>11%) were the major selenium species, followed by methylselenocysteine and selenourea. Therefore, selenium-enriched pork produced from selenomethionine is a good source for improving human dietary selenium intake.

Nutraceutical formulation, characterisation, and in-vitro evaluation of methylselenocysteine and selenocystine using food derived chitosan:zein nanoparticles.

Selenoamino acids (SeAAs) have been shown to possess antioxidant and anticancer properties. However, their bioaccessibility is low and they may be toxic above the recommended nutritional intake level, thus improved targeted oral delivery methods are desirable. In this work, the SeAAs, Methylselenocysteine (MSC) and selenocystine (SeCys2) were encapsulated into nanoparticles (NPs) using the mucoadhesive polymer chitosan (Cs), via ionotropic gelation with tripolyphosphate (TPP) and the NPs produced were then coated with zein (a maize derived prolamine rich protein). NPs with optimized physicochemical properties for oral delivery were obtained at a 6: 1 ratio of Cs:TPP, with a 1:0.75 mass ratio of Cs:zein coating (diameter ~260 nm, polydispersivity index ~0.2, zeta potential >30 mV). Scanning Electron Microscopy (SEM) analysis showed that spheroidal, well distributed particles were obtained. Encapsulation Efficiencies of 80.7% and 78.9% were achieved, respectively, for MSC and SeCys2 loaded NPs. Cytotoxicity studies of MSC loaded NPs showed no decrease in cellular viability in either Caco-2 (intestine) or HepG2 (liver) cells after 4 and 72 h exposures. For SeCys2 loaded NPs, although no cytotoxicity was observed in Caco-2 cells after 4 h, a significant reduction in cytotoxicity was observed, compared to pure SeCys2, across all test concentrations in HepG2 after 72 h exposure. Accelerated thermal stability testing of both loaded NPs indicated good stability under normal storage conditions. Lastly, after 6 h exposure to simulated gastrointestinal tract environments, the sustained release profile of the formulation showed that 62 ±â€¯8% and 69 ±â€¯4% of MSC and SeCys2, had been released from the NPs respectively.

Assessing bioaccessibility of Se and I in dual biofortified radish seedlings using simulated in vitro digestion.

Selenium (Se) and iodine (I) are essential elements for humans, and biofortification of vegetables with these elements is an effective way to amend their deficiencies in the diet. In this study, the distribution and transformation of Se and I species were investigated in radish seedlings that were simultaneously supplemented with these two elements; the fate and the bioaccessibility of Se and I species were dynamically surveyed in the oral, gastric and intestinal phases using a simulated in vitro digestion method. The radish seedlings were cultivated in hydroponic conditions with Se (IV), Se (VI), I- and IO3- (each 1 mg L-1). The results revealed that Se-methylselenocysteine (MeSeCys), selenocystine (SeCys2), selenomethionine (SeMet) and Se (VI) were present in radish, and MeSeCys was the dominant species in both gastric and intestinal extracts, comprising 32.7 ±â€¯1.5% and 39.6 ±â€¯1.1% of the total content, respectively. I- was also the dominant species, which accounted for 57.1 ±â€¯2.1%, 46.6 ±â€¯1.5% and 68.8 ±â€¯1.8% of the total digested content respectively in the oral, gastric and intestinal extracts. Meanwhile, IO3- was absent and organic I accounted for approximately 20%. The bioaccessibility of Se and I in the intestinal phase reached 95.5 ±â€¯2.5% and 85.8 ±â€¯0.9%, respectively; although after dialysis through membranes, the data reduced to 60.1 ±â€¯2.8% and 39.6 ±â€¯0.8%, respectively. Contents of MeSeCys and I- increased from the oral to intestinal phase and the bioaccessibility of both Se and I in radish was above 85%. So radish is suitable as a potential dietary source of Se and I with biofortification.

Simultaneous selenium and sulfur speciation analysis in cultivated Pleurotus pulmonarius mushroom.

Selenium (Se) and sulfur (S) speciation analysis in edible and medicinal Se enriched P. pulmonarius extracts was performed. Mycelium, colonized substrate, and fruiting bodies at different harvesting times were analyzed using ion-pairing reversed-phase chromatography coupled to an ICPMS/MS detector. Extraction efficiencies in enzymatically digested and aqueous extracts were between 45.3 and 109% for Se, depending on the sample type. Selenomethionine (Se-Met) was found to be the major Se-compound, together with a number of unknown Se-species. Cystine (Cys2), methionine (Met), and sulfate were also detected and quantified in all samples. Most of the Se-Met (84.0%) and Met (75.8%) were found to be in free form in the fruiting body, in contrast with the mycelium where 53.4% of Se-Met and 80.5% of Met is incorporated into proteins.

Selenium species determination in foods harvested in Seleniferous soils by HPLC-ICP-MS after enzymatic hydrolysis assisted by pressurization and microwave energy.

Fast, green, automated, highly efficient and accurate methodology for extracting selenium species in foods samples (Brazil nut, golden berries and heart of palm) harvested in seleniferous soils by using pressurized-assisted enzymatic hydrolysis (PAEH) and microwave-assisted enzymatic hydrolysis (MAEH) were optimized. After foods defatting or drying, selenium species were released using protease XIV and enzyme activator in 7 and 12 min for PAEH and MAEHmethods, respectively. Inductively coupled plasma - mass spectrometry (ICP-MS) and high performance liquid chromatography (HPLC) coupled with ICP-MS detection were used to assess total selenium and selenium species contents in the enzymatic extracts. Analytical performances, such as limits of quantification (0.032-0.599 µg g-1 and 0.014-0.240 µg g-1 for PAEH and MAEH, respectively), repeatability (11-14.5%) and accuracy of the over-all procedures were established. Selenomethionine (SeMet) were detected in all analyzed samples and selenocystine (SeCys2) in Brazil nut; however, SeMet and SeCys2 levels were only quantified in Brazil nut. Inorganic selenium species were not detected in any sample. The presence of SeMet and SeCys2 and the absence of oxidized selenium methionine (SeOMet) in the enzymatic extracts were confirmed by Orbitrap mass spectrometry.

Dietary cystine is important to maintain plasma mercaptalbumin levels in rats fed low-protein diets.

The oxidized/reduced state of plasma albumin in rats is influenced by the quantity of dietary protein. However, the effects of the protein quality on the oxidized/reduced state of plasma albumin are not clear. We hypothesized that the quality of dietary protein might modulate the oxidized/reduced state of plasma albumin. The aim of the present study was to examine whether the amino acid composition of dietary protein modulates the oxidized/reduced state of plasma albumin in rats. Male Sprague-Dawley rats were fed low-protein diets containing 5% casein (CA), 5% egg white (EW), or 6% wheat gluten (WG) for 2 weeks. The plasma albumin concentration gradually decreased in rats fed each diet; however, there was no significant difference among the groups. In rats fed the 5% CA diet, the percentage of mercaptalbumin within the total plasma albumin was significantly lower than in those fed the EW or WG diet. Compared with EW or WG, CA contains lower amounts of glycine and cystine. In rats fed a 5% CA diet supplemented with cystine, the percentage of mercaptalbumin was significantly higher than that in rats fed a 5% CA diet supplemented with glycine. The expression of hepatic eukaryotic initiation factor 4E-binding protein 1 was significantly lower in rats fed the cystine-supplemented diet than in those fed the glycine-supplemented diet. These results suggest that dietary protein with a high cystine content maintains plasma mercaptalbumin levels in rats fed low-protein diets.

Effects of Chinese Cooking Methods on the Content and Speciation of Selenium in Selenium Bio-Fortified Cereals and Soybeans.

Cereals and soybeans are the main food sources for the majority of Chinese. This study evaluated the effects of four common cooking methods including steaming, boiling, frying, and milking on selenium (Se) content and speciation in seven selenium bio-fortified cereals and soybeans samples. The Se concentrations in the selected samples ranged from 0.91 to 110.8 mg/kg and selenomethionine (SeMet) was detected to be the main Se species. Total Se loss was less than 8.1% during the processes of cooking except milking, while 49.1% of the total Se was lost in milking soybean for soy milk due to high level of Se in residuals. It was estimated that about 13.5, 24.0, 3.1, and 46.9% of SeMet were lost during the processes of steaming, boiling, frying, and milking, respectively. Meanwhile, selenocystine (SeCys2) and methylselenocysteine (SeMeCys) were lost completely from the boiled cereals. Hence, steaming and frying were recommended to cook Se-biofortified cereals in order to minimize the loss of Se.

Selenium speciation in wheat grain varies in the presence of nitrogen and sulphur fertilisers.

This study investigated whether selenium species in wheat grains could be altered by exposure to different combinations of nitrogen (N) and sulphur (S) fertilisers in an agronomic biofortification experiment. Four Australian wheat cultivars (Mace, Janz, Emu Rock and Magenta) were grown in a glasshouse experiment and exposed to 3 mg Se kg-1 soil as selenate (SeVI). Plants were also exposed to 60 mg N kg-1 soil as urea and 20 mg S kg-1 soil as gypsum in a factorial design (N + S + Se; N + Se; S + Se; Se only). Plants were grown to maturity with grain analysed for total Se concentrations via ICP-MS and Se species determined via HPLC-ICP-MS. Grain Se concentrations ranged from 22 to 70 µg Se g-1 grain (dry mass). Selenomethionine (SeMet), Se-methylselenocystine (MeSeCys), selenohomolanthionine (SeHLan), plus a large concentration of uncharacterised Se species were found in the extracts from grains. SeMet was the major Se species identified accounting for between 9 and 24 µg Se g-1 grain. Exposure to different N and S fertiliser combinations altered the SeMet content of Mace, Janz and Emu Rock grain, but not that of Magenta. MeSeCys and SeHLan were found in far lower concentrations (<4 µg Se g-1 grain). A large component of the total grain Se was uncharacterisable (>30 % of total grain Se) in all samples. When N fertiliser was applied (with or without S), the proportion of uncharacterisable Se increased between 60 and 70 % of the total grain Se. The data presented here indicate that it is possible to alter the content of individual Se species in wheat grains via biofortification combined with manipulation of N and S fertiliser regimes. This has potential significance in alleviating or combating both Se deficiency and Se toxicity effects in humans.

Trace elements in urinary stones: a preliminary investigation in Fars province, Iran.

In view of the high incidence rate of urinary stones in the south and southwest of Iran, this paper investigates trace elements content including heavy metals in 39 urinary stones, collected from patients in Fars province, Iran. The mineralogy of the stones is investigated using X-ray diffractometry. The samples are classified into five mineral groups (calcium oxalate, uric acid, cystine, calcium phosphate and mixed stone). Major and trace elements in each group were determined using ICP-MS method. P and Ca constitute the main elements in urinary stones with Ca being more affine to oxalates while other alkali and alkaline earths precipitate with phosphate. Significant amounts of trace elements, especially Zn and Sr, were found in urinary calculi (calcium oxalate and phosphates) relative to biominerals (uric acid and cystine). Among urinary calculi, calcium phosphate contains greater amounts of trace metal than calcium oxalate. Phosphates seem to be the most important metal-bearing phases in urinary stones. Results indicate that concentrations of elements in urinary stones depend on the type of mineral phases. Significant differences in elements content across various mineralogical groups were found by applying statistical methods. Kruskal-Wallis test reveals significant difference between Ca, P, K, Na, Mg, S, Zn, Sr, Se, Cd, and Co content in different investigated mineral groups. Moreover, Mann-Whitney test differentiates Ca, Na, Zn, Sr, Co, and Ni between minerals in oxalate and uric acid stones. This study shows that urinary stone can provide complementary information on human exposure to elements and estimate the environmental risks involved in urinary stones formation.

Investigation of the reactions of acrylamide during in vitro multistep enzymatic digestion of thermally processed foods.

This study investigated the fate of acrylamide in thermally processed foods after ingestion. An in vitro multistep enzymatic digestion system simulating gastric, duodenal and colon phases was used to understand the fate of acrylamide in bakery and fried potato products. Acrylamide levels gradually decreased through gastric, duodenal and colon phases during in vitro digestion of biscuits. At the end of digestion, acrylamide reduction was between 49.2% and 73.4% in biscuits. Binary model systems composed of acrylamide and amino acids were used to understand the mechanism of acrylamide reduction. High-resolution mass spectrometry analyses confirmed Michael addition of amino acids to acrylamide during digestion. In contrast to bakery products, acrylamide levels increased significantly during gastric digestion of fried potatoes. The Schiff base formed between reducing sugars and asparagine disappeared rapidly, whereas the acrylamide level increased during the gastric phase. This suggests that intermediates like the Schiff base that accumulate in potatoes during frying are potential precursors of acrylamide under gastric conditions.

Mechanism of a decrease in potency for the recombinant influenza A virus hemagglutinin H3 antigen during storage.

The recombinant hemagglutinin (rHA)-based influenza vaccine Flublok® has recently been approved in the United States as an alternative to the traditional egg-derived flu vaccines. Flublok is a purified vaccine with a hemagglutinin content that is threefold higher than standard inactivated influenza vaccines. When rHA derived from an H3N2 influenza virus was expressed, purified, and stored for 1 month, a rapid loss of in vitro potency (∼50%) was observed as measured by the single radial immunodiffusion (SRID) assay. A comprehensive characterization of the rHA protein antigen was pursued to identify the potential causes and mechanisms of this potency loss. In addition, the biophysical and chemical stability of the rHA in different formulations and storage conditions was evaluated over time. Results demonstrate that the potency loss over time did not correlate with trends in changes to the higher order structure or hydrodynamic size of the rHA. The most likely mechanism for the early loss of potency was disulfide-mediated cross-linking of rHA, as the formation of non-native disulfide-linked multimers over time correlated well with the observed potency loss. Furthermore, a loss of free thiol content, particularly in specific cysteine residues in the antigen's C-terminus, was correlated with potency loss measured by SRID.

Chemical characterisation and speciation of organic selenium in cultivated selenium-enriched Agaricus bisporus.

The selenium concentration in Agaricus bisporus cultivated in growth compost irrigated with sodium selenite solution increased by 28- and 43-fold compared to the control mushroom irrigated solely with water. Selenium contents of mushroom proteins increased from 13.8 to 60.1 and 14.1 to 137 µgSe/g in caps and stalks from control and selenised mushrooms, respectively. Selenocystine (SeCys; detected as [SeCys]2 dimer), selenomethionine (SeMet), and methyl-selenocysteine (MeSeCys) were separated, identified and quantified by liquid chromatography-electrospray ionisation-mass spectrometry from water solubilised and acetone precipitated proteins, and significant increases were observed for the selenised mushrooms. The maximum selenoamino acids concentration in caps and stalks of control/selenised mushrooms was 4.16/9.65 µg/g dried weight (DW) for SeCys, 0.08/0.58 µg/g DW for SeMet, and 0.031/0.10 µg/g DW for MeSeCys, respectively. The most notable result was the much higher levels of SeCys accumulated by A. bisporus compared to SeMet and MeSeCys, for both control and selenised A. bisporus.

In vitro bioavailability of total selenium and selenium species from seafood.

In vitro bioavailability of total selenium and selenium species from different raw seafood has been assessed by using a simulated gastric and intestinal digestion/dialysis method. Inductively coupled plasma-mass spectrometry (ICP-MS) was used to assess total selenium contents after a microwave assisted acid digestion, and also to quantify total selenium in the dialyzable and non-dialyzable fractions. Selenium speciation in the dialyzates was assessed by high performance liquid chromatography (HPLC) coupled with ICP-MS detection. Major Se species (selenium methionine and oxidized selenium methionine) from dialyzate were identified and characterized by HPLC coupled to mass spectrometry (HPLC-MS). Selenocystine was detected at low concentrations while Se-(Methyl)selenocysteine and inorganic selenium species (selenite and selenate) were not detected in the dialyzate. Low bioavailability percentages for total selenium (6.69±3.39 and 5.45±2.44% for fish and mollusk samples, respectively) were obtained. Similar bioavailability percentages was achieved for total selenium as a sum of selenium species (selenocystine plus oxidized selenium methionine and selenium methionine, mainly). HPLC-MS data confirmed SeMet oxidation during the in vitro procedure.

In vivo reflectance confocal microscopy of the skin: a noninvasive means of assessing body cystine accumulation in infantile cystinosis.

BACKGROUND: Patients with infantile nephropathic cystinosis have progressive accumulation of cystine in tissues leading to delayed extrarenal complications. No simple tool is available to evaluate the level of body cystine accumulation. OBJECTIVE: We sought to determine the value of in vivo reflectance confocal microscopy of the skin in patients with infantile nephrogenic cystinosis. METHODS: Nine patients and control subjects were recruited for this study. Images were acquired by means of a near-infrared reflectance confocal laser scanning microscope. RESULTS: Scattered bright particles within the papillary dermis were observed in all patients but not in control subjects. The density of particles ranged from numerous (+++) to very few (+/-) and their distribution was heterogeneous. Electron microscopy confirmed that these particles corresponded to cystine crystal deposits within dermal fibroblasts. The density of cystine crystals within the dermis was greater in older patients, in patients with a high leukocyte cystine concentration, and with delayed cysteamine therapy. There was no correlation between the density of cystine deposits and renal disease or hypopigmentation but high levels of deposition occurred in association with extrarenal manifestations. LIMITATIONS: This is a preliminary study on a small sample of patients. Repeated examination and longer follow-up is necessary. CONCLUSION: In vivo reflectance confocal microscopy of the skin appears to be a noninvasive means of assessing body cystine accumulation in infantile cystinosis and could be used as a complementary marker of treatment response in addition to leukocyte cystine measurement.

Estimation of urinary stone composition by automated processing of CT images.

The objective of this article was developing an automated tool for routine clinical practice to estimate urinary stone composition from CT images based on the density of all constituent voxels. A total of 118 stones for which the composition had been determined by infrared spectroscopy were placed in a helical CT scanner. A standard acquisition, low-dose and high-dose acquisitions were performed. All voxels constituting each stone were automatically selected. A dissimilarity index evaluating variations of density around each voxel was created in order to minimize partial volume effects: stone composition was established on the basis of voxel density of homogeneous zones. Stone composition was determined in 52% of cases. Sensitivities for each compound were: uric acid: 65%, struvite: 19%, cystine: 78%, carbapatite: 33.5%, calcium oxalate dihydrate: 57%, calcium oxalate monohydrate: 66.5%, brushite: 75%. Low-dose acquisition did not lower the performances (P < 0.05). This entirely automated approach eliminates manual intervention on the images by the radiologist while providing identical performances including for low-dose protocols.

A novel HPLC-UV/nano-TiO2-chemiluminescence system for the determination of selenocystine and selenomethionine.

Active oxygen species from the photocatalytic reaction in aqueous solution react with luminol to emit strong chemiluminescence (CL), and this can be inhibited by the UV decomposed-products of selenocystine (SeCys) or selenomethionine (SeMet). Based on this phenomenon, a novel hyphenated technique, HPLC-UV/nano-TiO(2)-CL, was established for the determination of SeCys and SeMet. The effects of pH, the UV irradiation time, the TiO(2) coated on the inner surface of the reaction tubing, and the Co(2+) catalyst concentration on the CL intensity and/or chromatographic resolution were systematically investigated. Under these optimized conditions, the inhibited CL intensity has a good linear relationship with the concentration of SeCys in the range of 0.04-10.6 microg mL(-1) or SeMet in the range of 0.05-12.4 microg mL(-1), with a limit of detection (S/N=3) of 6.4 microg L(-1) for SeCys or 12 microg L(-1) for SeMet. As an example, the method was preliminarily applied to the determination of the selenoamino acids in garlic and rabbit serum, with a recovery of 88-104%.

[Modulation of the phenotypic expression in the patient with cystinuria: influence of therapeutic intervention and diet]. / Modulacion de la expresion fenotipica del paciente con cistinuria: influencia de la intervencion terapeutica y de la dieta.

OBJECTIVES: The final phenotype of patients with cystinuria depends on the absence or molecular defect, more or less acute, of the transport of cystine and dibasic aminoacids, and, also on environmental factors. The objective of this work is to study the effect of the modulation of some environmental factors (urinary pH, intake of liquids, pharmacological treatment and, specially, diet) on the final phenotype of the patient with cystinuria. METHODS: We study 45 patients with cystinuria (25 men and 20 women), 42 relatives (15 men and 27 women) and 90 unrelated controls. Anthropometric, clinical (personal and familiar history of urinary infections, colics and calculi expulsion), biochemical (microscopy analysis of urine and urinary aminoacids cuantification) and life style (diet and medical treatment) variables were obtained. Statistical analysis was performed using tests to compare means and frequencies and, also, logistic regression and multivariate analysis. RESULTS: Of the 45 patients with cystinuria, only 20% showed cystine cristalls in urine, the rest of the phenotypical manifestations of cystinuria were found with the same prevalence as in relatives and in the control group. 50% of the patients did not undergo any therapeutic intervention; of these, only 50% were effective. In patients with cystinuria, the presence of cystine cristalls was associated with a diet rich in meats and poor in milk products (p < 0.05). Meat consumption also tend to associate with a higher risk of urinary infections, meanwhile the stone expulsion showed a negative tendance with a diet rich in phytate. The elevate consumption of oranges and mandarins was the variable of the diet which was more associated with urinary aminoacids concentrations, specially with lower levels of lysine and arginine (p < 0.05). CONCLUSIONS: Some components of the diet, in addition to standard treatment, modulate the phenotypical manifestations of cystinuria.

A novel multielemental scanning thermal analysis (MESTA) method for the identification and characterization of solid substances.

Identification and characterization of solid samples has been relatively difficult due to the limited separation techniques available. Reported here is the development of a multielemental scanning thermal analysis (MESTA) method that provides a simple, rapid, and sensitive alternative for routine examination of solid samples. A MESTA system heats up a sample in an enclosed quartz tube from ambient to 800 degree C at a constant heating rate and under a given atmosphere. The volatile components in the sample are carried to a high-temperature combustion tube where the C, N, and S are oxidized to their respective oxides and detected by the detectors. The result is the simultaneous C, N, and S thermograms of a sample that can be used as chemical signatures for identification and characterization purposes. Sample heating rate, oxygen content of the carrier gas, and the possible interactions among the ingredients of a sample would all affect the outcome of an analysis. These effects need to be understood for a specific application. The general instrumentation, technique, usefulness, and interpretation of the MESTA are presented with examples. The simplicity and cost-effectiveness of the MESTA make it a promising tool for routine chemical analysis of solid substances.

Selenium speciation by high-performance anion-exchange chromatography-post-column UV irradiation coupled with atomic fluorescence spectrometry.

A technique for the speciation of selenomethylcysteine (SeMeCys), selenocystine (SeCys), selenite [Se(IV)] and selenomethionine (SeMet) was established in this paper using high-performance anion-exchange chromatography coupled with atomic fluorescence spectrometry (HPAEC-AFS). Analytes were separated on an AminoPac PA10 column and then digested by on-line ultraviolet (UV) irradiation, which destroyed organic compound structure. Hydride generation was used as an available sample introduction technique for atomic fluorescence detection. The detection limits of four compounds were 1-5 microg/L (250 microL injection, 10 times of the baseline noise). The relative standard deviations (RSDs), calculated from seven consecutive injections of 100 microg/L standard mixtures, were from 2 to 4%. Selenious yeast tablet, which had been proposed as selenium supplement, and human urine collected from a volunteer were analyzed. Good spiked recoveries from 86 to 103% were obtained.

Direct amino acid analysis method for speciation of selenoamino acids using high-performance anion-exchange chromatography coupled with integrated pulsed amperometric detection.

Speciation analysis of selenomethylcysteine (SeMeCys), selenomethionine (SeMet) and selenocystine (SeCys) has been performed using a direct amino acid analysis method with high-performance anion-exchange chromatography (HPAEC) coupled with integrated pulsed amperometric detection (IPAD). Three selenoamino acids could be baseline-separated from 19 amino acids using gradient elution conditions for amino acids and determined under new six-potential waveform. Detection limits for SeMeCys, SeMet and SeCys were 0.25, 1 and 20 microg/L (25 microL injection, 10 times of the baseline noise), respectively. The relative standard deviations (RSDs) of 200 microg/L SeMeCys, SeMet and SeCys were 3.1, 4.1 and 2.8%, respectively (n=9, 25 microL injection). The proposed method has been applied for determination of selenoamino acids in extracts of garlic and selenious yeast granule samples. No selenoamino acids were found in garlic. Both SeMet and SeCys were detected in selenious yeast tablet with the content of 45 and 129 microg Se/g, respectively. Selenoamino acids standards were spiked in garlic and yeast granule samples and the recovery ranged from 90 to 106%.