D and18O enrichment measurements in biological fluids in a continuous-flow elemental analyser with an isotope-ratio mass spectrometer using two configurations (original) (raw)
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Determination of deuterium level in biological fluids by isotope ratio mass spectrometry
Biological Mass Spectrometry, 1987
Water is produced by vacuum sublimation of biological fluids directly into reaction vessels in preparation for reduction using zinc. Following heating to 450 "C the hydrogen produced is admitted directly to the mass spectrometer. The standard derivation, u,,, of analysis of water samples was 1.08-1.23% while for blood plasma u, = 2.02-2.62%. The method allows the determination of very low levels of deuterium in biological fluids, thus allowing very small doses of deuterium oxide to be used in studies of body water in animals and possibly humans.
Rapid Communications in Mass Spectrometry, 2009
The doubly labelled water method is valuable for measuring energy expenditure in humans. It usually involves blood or urine sampling, which might be difficult in neonates and children with cerebral palsy or other disabilities. We therefore aimed to validate a method making use of saliva samples analyzed by automated thermal conversion elemental analyzer in combination with isotope ratio mass spectrometry (TC-EA/IRMS). The subjects received labelled water orally and urine and saliva samples were collected and analyzed. Deuterium as well as oxygen 18 was measured in one single run using a peak jump method. Excellent linearity was found for measurement of enrichments of deuterium (R 2 ¼ 0.9999) and oxygen 18 (R 2 ¼ 0.9999). The intra-assay precision and the inter-assay precision of the measurement of two standards were good for both deuterium and oxygen 18 . The variation between urine and saliva samples was small (4.83% for deuterium and 2.33% for oxygen 18 n ¼ 40). Saliva sampling is to be preferred, therefore, as it can be easily collected and is non-invasive. Moreover, its time of production is almost exactly known. The TC-EA/IRMS method is a good alternative to the more laborious off-line IRMS measurements.
Clinical Chemistry, 1997
The determination of trace and ultratrace elements in biological fluids, including urine and serum, by inductively coupled plasma mass spectrometry (ICP-MS) is discussed. Nonspectral interferences and their corrections by external calibration and calibrator addition are discussed in detail. External calibration with internal calibration and dilution is mostly sufficient to correct for encountered biological matrix effects. For some elements, such as Cs and Zn, the use of calibrator addition provides more accurate results. The importance of spectral interferences and their elimination by isotope selection was also studied. Two examples, Cu and Zn, demonstrate the prime importance of selecting an isotope with minimal polyatomic interferences for analysis. By using 65Cu and 68Zn, accurate results for urine and serum can be obtained without excessive pretreatment of samples. Two reference materials, Bio-Rad Lyphochek urine and Kaulson Contox sera, were analyzed. Accuracy was evaluated b...
High-precision continuous-flow isotope ratio mass spectrometry
Mass Spectrometry Reviews, 1997
Although high-precision isotope determinations are routine in 1997), nitrification rates in forests (Starle & Hart, 1997), many areas of natural science, the instrument principles for their biodegradation (Aggarwal et al., 1997), and the climate measurements have remained remarkably unchanged for four history of the earth (Schoell et al., 1994). In ecology and decades. The introduction of continuous-flow techniques to isobiogeochemistry alone, two volumes (Ehleringer & Runtope ratio mass spectrometry (IRMS) instrumentation has predel, 1988; Ehleringer, Hall, & Farquhar, 1993) and at least cipitated a rapid expansion in capabilities for high-precision one meeting (Griffiths, 1996) devoted to applications of measurement of C, N, O, S, and H isotopes in the 1990s. Elemenhigh-precision isotope measurements have appeared in the tal analyzers, based on the flash combustion of solid organic last few years. Isotope ratio MS (IRMS) has penetrated samples, are interfaced to IRMS to facilitate routine C and N areas of biological science to a greater degree than organic isotopic analysis of unprocessed samples. Gas/liquid equilibramass spectrometry. In addition to studies of natural varitors have automated O and H isotopic analysis of water in untreated aqueous fluids as complex as urine. Automated cryo-ability, high-precision isotope measurements facilitate a genic concentrators permit analysis at part-per-million concennumber of tracer techniques in the biomedical sciences, trations in environmental samples. Capillary gas chromatograincluding the doubly labeled water method for energy exphy interfaced to IRMS via on-line microchemistry facilitates penditure (Schoeller et al., 1986), protein turnover studies compound-specific isotope analysis (CSIA) for purified organic (Chapman et al., 1990), fat metabolism (Brenna, 1997), analytes of 1 nmol of C, N, or O. GC-based CSIA for hydrogen and a range of breath tests with the potential to revolutionand liquid chromatography-based interfaces to IRMS have both ize clinical diagnostic testing (Ghoos, Rutgeerts, & van been demonstrated, and continuing progress promises to bring Trappen, 1995). these advances to routine use. Automated position-specific iso-The early history of MS was dominated by physical tope analysis (PSIA) using noncatalytic pyrolysis has been measurements to establish the nominal, terrestrial isotopic shown to produce fragments without appreciable carbon scramabundances of the elements. The early parabola method bling or major isotopic fractionation, and shows great promise for intramolecular isotope ratio analysis. Finally, IRMS notation
Calibration for the determination of 19 trace elements in serum and urine
Toxicological & Environmental Chemistry, 2018
and Hg in urine and serum by inductively coupled plasma mass spectrometry. The samples were directly analyzed after 1/20 (v/v) dilution in 0.4 % (v/v) HNO 3 and 0.005 % Triton X-100. Three calibration modes were tested: aqueous and matrix matching with urine and serum. The accuracy was tested using reference materials of serum, urine and spiking. Results showed that the use of matrix matching calibration reduced the interferences and improved the recoveries for Al, Co, Pb and I in urine. The matrix matching didn't affect the results considerably for serum. When serum was spiked with As, Co, Cs, Pb, U, Hg, I, Ba, Al, Cr and Ni, only matrix matching presented good recoveries. Helium was used as a collision cell gas reducing effectively polyatomic interferences for Al, Mn, Cu, Ni, Cr, Zn, As, and Fe. Selection of the best internal standard was carried out for each element. The use of diluted HNO 3 improved the limit of detection. Finally, the method was applied successfully in samples of urine from workers occupationally exposed.
Microchemical Journal, 2014
This article describes the application of on-line isotope dilution mass spectrometry with inductively coupled plasma (OID-ICP-MS) to the field of trace metal analysis (B, Cd, Cr, Fe, Ni, Pb and Zn) in water samples by the certified reference material (CRM) characterization. Drinking, natural and waste water certified reference materials were analyzed. Emphasis is placed on OID-ICP-MS measurements of highest analytical quality and their validation against direct external calibration mass spectrometry with inductively coupled plasma analysis (ICP-MS). Differences in the calibration strategies such as single OID-ICP-MS versus direct external calibration ICP-MS were discussed. In general, it can be stated that OID-ICP-MS offers high accurate and precise results with small measurement uncertainties, when properly applied, compared to external calibration. Thus, OID-ICP-MS proved to be an ideal solution for routine water sample analysis, increasing sample throughput without any previous sample handling and improving the quality and reliability of the analytical results.
2011
Dissertation supervised by Professor H. M. "Skip" Kingston Previous work by our research group demonstrated that quantitative chemical analysis of analytes, such as mercury and chromium species, in environmental matrices could be successfully carried out without using calibration curves and with correction for species interconversion by using EPA Method 6800A. This method encompasses isotope dilution mass spectrometry (IDMS) and speciated isotope dilution mass spectrometry (SIDMS), both of which are described in detail in chapter 1. Research described in this dissertation expands upon our earlier work by applying the method to the speciation of mercury in biological matrices, the speciation of glutathione in red blood cells and whole blood, and the analysis of enzyme activity in mammalian tissue.