Quantitative evaluation of carbon isotopic fractionation during reversed-phase high-performance liquid chromatography

Caimi, Richard J.; Brenna, J. Thomas

doi:10.1016/s0021-9673(96)00694-2

Cited by 48 publications

(21 citation statements)

References 15 publications

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“…Figure 2 shows the fractionation measured within a peak of valine during the first RP separation of our chromatographic method. Our observations are consistent with the fractionation reported by Caimi and Brenna [37]. Taking the weighted average of the runs leads to correct isotope ratio values for valine ( Table 2), implying that if the entire peak is collected values will be accurate.…”

Section: Isotope Fractionation Within the Peakssupporting

confidence: 91%

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Preparative separation of underivatized amino acids for compound‐specific stable isotope analysis and radiocarbon dating of hydrolyzed bone collagen

Tripp¹,

McCullagh

Hedges

2006

J of Separation Science

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Analysis of stable and radioactive isotopes from bone collagen provides useful information to archaeologists about the origin and age of bone artifacts. Isolation and analysis of single amino acids from the proteins can provide additional and more accurate information by removing contamination and separating a bulk isotope signal into its constituent parts. In this paper, we report a new method for the separation and isolation of underivatized amino acids from bone collagen, and their analysis by isotope ratio MS and accelerator MS. RP chromatography is used to separate the amino acids with nonpolar side chains, followed by an ion pair separation to isolate the remaining amino acids. The method produces single amino acids with little or no contamination from the separation process and allows for the measurement of accurate stable isotope ratios and pure samples for radiocarbon dating.

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Section: Isotope Fractionation Within the Peakssupporting

confidence: 91%

“…While O'Connell and Hedges [7] observed no fractionation when separating Fmoc-derivatized amino acids, others [37] have reported a fractionation of about 7? in carbon between the first and last part of peaks in RP chromatography.…”

Section: Isotope Fractionation Within the Peaksmentioning

confidence: 96%

Preparative separation of underivatized amino acids for compound‐specific stable isotope analysis and radiocarbon dating of hydrolyzed bone collagen

Tripp¹,

McCullagh

Hedges

2006

J of Separation Science

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“…The data are consistent with the fractionation factors Rliquid-vapor ) p 12C /p 13C ) 0.99980 ( 0.00003 for BTEXaromatics and Rliquid-vapor ) 0.99930 ( 0.00005 for trichloroethene. All these sorption and evaporation-based isotope fractionations obey the same rule, that "van der Waals interactions with the nonpolar component of the column (or the nonpolar solvent phase) are reduced for the heavy isotopomers" (11). It is remarkable that the fractionation factors for vapor condensation and hydrophobic sorption from water are similar (e.g., 1/Rliquid-vapor ≈ Rsorption).…”

Section: Resultsmentioning

confidence: 82%

Carbon Isotope Fractionation of Organic Contaminants Due to Retardation on Humic Substances: Implications for Natural Attenuation Studies in Aquifers

Kopinke

Georgi

Voskamp

et al. 2005

Environ. Sci. Technol.

122

146

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Experimental approaches were developed which permit the measurement of carbon isotope effects during partitioning of organic compounds between water and humic substances. Fractionation factors alpha(sorption) = K(OC)12C/K(OC)13C for carbon isotopomers of benzene (1.00044 +/- 0.00015) and toluene (1.00060 +/- 0.00010) were determined from a 10-step batch experiment. Similar fractionation factors were estimated for benzene (1.00017), 2,4-dimethylphenol (1.00035), and o-xylene (< or = 1.00092) from chromatographic experiments. The latter method is based on chromatographic amplification of the fractionation effect (deltadelta13C) in an HPLC column with humic acid (HA) as the stationary phase. Possible implications of the sorption-based isotope fractionation for assessment of natural attenuation processes in contaminated aquifers are discussed. Depending on the aquifer properties (organic carbon content, heterogeneity) together with the plume source, length, and status (stationary or expanding), scenarios may be constructed where sorption-based isotope fractionation competes significantly with that caused by chemical or microbial degradation processes.

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“…Hydrophobic sorption processes are connected to small isotope effects, resulting from the reduction of nonspecific hydrophobic van der Waals interactions for heavier isotopologues (Caimi and Brenna 1997;Kopinke et al 2005a). In consequence, heavy isotopologues migrate faster than light isotopologues.…”

Section: Sorptionmentioning

confidence: 99%

“…However, contaminant transport in aquifers is influenced by multiple sorption-desorption steps, similar to analytes in a reversed-phase high-performance liquid chromatography (HPLC) column (Schüth et al 2003;Kopinke et al 2005a). The cumulative isotope effect of many partitioning steps may then lead to significant shifts in the isotope ratio (Caimi andBrenna 1997, Turowski et al 2003), depending on the strength of retardation (mainly determined by the organic carbon content) and the separation efficiency of the aquifer (the number of sorption-desorption steps). Kopinke et al (2005a) found small but significant carbon isotope fractionation factors associated with sorption of benzene, 2,4-dimethylphenol, toluene, and o-xylene to humic acid, representing organic matter in the aquifer, in multi-step sorption batch and reversed-phase HPLC experiments.…”

Section: Sorptionmentioning

confidence: 99%

Field applicability of Compound-Specific Isotope Analysis (CSIA) for characterization and quantification of in situ contaminant degradation in aquifers

Braeckevelt

Fischer

Kästner

2012

Appl Microbiol Biotechnol

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Microbial processes govern the fate of organic contaminants in aquifers to a major extent. Therefore, the evaluation of in situ biodegradation is essential for the implementation of Natural Attenuation (NA) concepts in groundwater management. Laboratory degradation experiments and biogeochemical approaches are often biased and provide only indirect evidence of in situ degradation potential. Compound-Specific Isotope Analysis (CSIA) is at present among the most promising tools for assessment of the in situ contaminant degradation within aquifers. One- and two-dimensional (2D) CSIA provides qualitative and quantitative information on in situ contaminant transformation; it is applicable for proving in situ degradation and characterizing degradation conditions and reaction mechanisms. However, field application of CSIA is challenging due to a number of influencing factors, namely those affecting the observed isotope fractionation during biodegradation (e.g., non-isotope-fractionating rate-limiting steps, limited bioavailability), potential isotope effects caused by processes other than biodegradation (e.g., sorption, volatilization, diffusion), as well as non-isotope-fractionating physical processes such as dispersion and dilution. This mini-review aims at guiding practical users towards the sound interpretation of CSIA field data for the characterization of in situ contaminant degradation. It focuses on the relevance of various constraints and influencing factors in CSIA field applications and provides advice on when and how to account for these constraints. We first evaluate factors that can influence isotope fractionation during biodegradation, as well as potential isotope-fractionating and non-isotope-fractionating physical processes governing observed isotope fractionation in the field. Finally, the potentials of the CSIA approach for site characterization and the proper ways to account for various constraints are illustrated by means of a comprehensive CSIA field study at the benzene, toluene, ethylbenzene, and xylene (BTEX)-contaminated site Zeitz.

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Quantitative evaluation of carbon isotopic fractionation during reversed-phase high-performance liquid chromatography

Cited by 48 publications

References 15 publications

Preparative separation of underivatized amino acids for compound‐specific stable isotope analysis and radiocarbon dating of hydrolyzed bone collagen

Preparative separation of underivatized amino acids for compound‐specific stable isotope analysis and radiocarbon dating of hydrolyzed bone collagen

Carbon Isotope Fractionation of Organic Contaminants Due to Retardation on Humic Substances: Implications for Natural Attenuation Studies in Aquifers

Field applicability of Compound-Specific Isotope Analysis (CSIA) for characterization and quantification of in situ contaminant degradation in aquifers

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