Determination of selenium in biological materials by stable isotope dilution gas chromatography-mass spectrometry

Reamer, D. C.; Veillon, Claude

doi:10.1021/ac00237a004

Cited by 88 publications

(18 citation statements)

References 41 publications

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“…All Se determinations were performed in a single laboratory, since interlaboratory comparisons may result in a wide variability of results [28]. Our data are in agreement with previous reports showing remarkable differences for blood Se levels in healthy people from different geograph ic environments [22].…”

Section: Discussionsupporting

confidence: 91%

Geographic Factors and Plasma Selenium in Uremia and Dialysis

Bonomini

Förster

Manfrini

et al. 1996

Nephron

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The importance of selenium (Se) as an essential trace element for man has been increasingly recognized. Blood Se levels in chronic uremic patients are frequently reported to be lower than in controls. Definitive determination of the Se status in uremic patients, however, is hampered by the wide range of blood Se content in humans from different parts of the world. The present study was designed to assess and compare the Se status in two European populations from Rostock (Germany) and Chieti (Italy). Plasma Se levels were evaluated in healthy controls, chronic renal failure nondialyzed patients (CRF) and hemodialysis patients (HD). All Se determinations were performed in a single laboratory. The Se concentration was significantly higher (p < 0.005) in Italian healthy controls than in German healthy controls. In contrast, Se levels were similar in both CRF and HD patients from both cities. In both countries, the Se concentration in CRF and HD patients was significantly lower (p < 0.001) than in their corresponding controls, but no difference between CRF and HD was found. CRF and HD patients from the two countries showed quite similar laboratory and anthropometric data. In CRF patients in Chieti, a significant (p < 0.05) negative correlation between plasma Se and serum creatinine was found. In both HD groups, the length of time on HD and type of membrane dialyzer used did not influence the Se status. A significant positive correlation (p < 0.01) between Se levels and the protein catabolic rate was found in both HD groups. Uremia seems to be a strong factor which overrules the difference in Se levels that is present in healthy adults from different European countries. Uremia in itself may influence and level the Se concentration in patients with geographic diversity.

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Section: Discussionsupporting

confidence: 91%

Geographic Factors and Plasma Selenium in Uremia and Dialysis

Bonomini

Förster

Manfrini

et al. 1996

Nephron

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“…Choline compounds partitioned into aqueous and non-aqueous solvents and analyzed directly by liquid chromatography/electrospray ionization-isotope dilution mass spectrometry Koc et al (2002) Elements (Ca, Mg, K, Na, P, Cu, Fe, Mn, Zn) ICP Dry ashing (500 8C AE 50 8C) and dissolution in concentrated HCl, or wet ashing (digestion in concentrated acid, with heat) of sample. Followed by appropriate dilution, followed by quantitation of each element using an ICP spectrometer and comparing the emission of the unknown sample against the emission of each element in standard solutions AOAC (2011) Se is measured by GC-MS using dual ion monitoring Reamer and Veillon (1981) a ESI, electrospray ionization; GC, gas chromatography; HPLC, high performance liquid chromatography; ICP, inductively coupled plasma emission spectroscopy; ID, isotope dilution; LC, liquid chromatography; MS, mass spectrometry; TCEP, tris(2-carboxyethyl)phosphine.…”

Section: Discussionmentioning

confidence: 99%

Nutrient composition of selected traditional United States Northern Plains Native American plant foods

Phillips

Pehrsson

Agnew

et al. 2014

Journal of Food Composition and Analysis

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“…This method yields very accurate and precise ratios in general and for Group IIA elements in particular. GC/MS analysis of volatile metal chelates, while excellent for the analysis of Se and Cr (Reamer and Viellon, 1981), has the drawback of significant sequential sample contamination problems ("memory") (Hachey et al, 1980). Whereas Mg isotope ratios have been determined by secondary ion mass spectrometry (SIMS) (Ramseyer et al, 1984), and isotope ratios of both Ca and Fe determined by fast atom bombardment (FAB), to date, TIMS has produced the best accuracy and precision.…”

Section: Methodsmentioning

confidence: 99%

Simultaneous bidirectional magnesium ion flux measurements in single barnacle muscle cells by mass spectrometry

Montes¹,

Sjodin²,

Yergey³

et al. 1989

Biophysical Journal

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Stable isotopes of Mg were used to measure bidirectional magnesium ion fluxes in single barnacle giant muscle fibers immersed in Ca- and Na-free, isosmotic media. Measurements were made using a mass spectrometric technique, thermal ionization mass spectrometry (TIMS), in conjunction with atomic absorption spectroscopy. Kinetic relations based on a first-order model were developed that permit the determination of unidirectional rate coefficients for Mg influx, ki, and efflux, ke, in the same experiment from knowledge of initial conditions and the initial and final ratios of 26Mg/24Mg and 25Mg/24Mg in ambient solutions (i.e., by isotope dilution). Such determinations were made for three values of the external Mg ion concentration: 5, 25, and 60 mM. At the concentration [Mg+2]o = 5 mM, ki and ke were about equal at a value of 0.01 min-1. At the higher values of [Mg+2]o, the values of ke increased along a curve suggesting saturation, whereas the values of ki remained essentially constant. As could be expected on the basis of a constant ki, the initial influx rate varied in direct linear proportion to [Mg+2]o, and was 11.8 pmol/cm2s when [Mg+2]o was 5 mM. However, the initial efflux rate appeared to increase nonlinearly with [Mg+2]o, varying from 13.4 pmol/cm2s ([ Mg+2]o = 5 mM) to approximately 80 pmol/cm2s ([ Mg+2]o = 60 mM). The results are consistent with a model that assumes Mg influx to be mainly an electrodiffusive inward leak with PMg = 0.07 cm/s and Mg efflux to be almost entirely by active transport processes. Where comparisons can be made, the rate coefficients determined from stable isotope measurements agree with those previously obtained using radioactive Mg. The rate coefficients can be used to correctly predict time-dependent changes in total fiber Mg content. The results support the conclusion that nonradioactive tracers can be used to measure ion fluxes and ion flux ratios in excitable cells; it is expected that this method will greatly assist in the study of Mg regulation in general.

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Determination of selenium in biological materials by stable isotope dilution gas chromatography-mass spectrometry

Cited by 88 publications

References 41 publications

Geographic Factors and Plasma Selenium in Uremia and Dialysis

Geographic Factors and Plasma Selenium in Uremia and Dialysis

Nutrient composition of selected traditional United States Northern Plains Native American plant foods

Simultaneous bidirectional magnesium ion flux measurements in single barnacle muscle cells by mass spectrometry

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