Quantification of Lambda (?) in multi-elemental compound-specific isotope analysis
نویسندگان
چکیده
In multi-elemental compound-specific isotope analysis the lambda (?) value expresses shift of one element versus a second element. dual-isotope plots, slope regression lines typical reveals footprint underlying effects allowing to distinguish degradation pathways an organic contaminant molecule in environment. While different conventions and fitting procedures are used literature determine ?, it remains unclear how they affect magnitude ?. Here we generate synthetic data for benzene ?2H ?13C with two enrichment factors ?H ?C using Rayleigh equation examine linear yield distinct Fitting error-free set graph plotting overestimates ? by 0.225%??H/?C, meaning that if ?H/?Cis larger than 22, is overestimated more 5%. The correct requires natural logarithmic transformation data. Using this transformation, ordinary (OLR), reduced major-axis (RMA) York methods find even large ?H/?C. dataset random errors let same conclusion positioned suitability each method. We conclude non-transformed ? values should be discontinued. validity most previous not compromised, although previously obtained ?H/?C could corrected our error estimation improve comparison.
منابع مشابه
Compound-specific isotope analysis
The isotopic composition, e.g. 14C/12C, 13C/12C, 2H/1H, 15N/14N and 18O/16O, of matter elements is heterogeneous. It is ruled by physical, chemical and biological mechanisms. Isotopes thus be enable to follow the fate of mineral and organic compounds during biogeochemical transformations. The determination of the isotopic composition of organic substances occurring at trace level into very comp...
متن کاملCompound-Specific Sulfur Isotope Analysis of Petroleum Gases.
We describe a simple, sensitive, and robust method for sulfur isotope ratio (34S/32S) analysis of ppm-level organic sulfur compounds (OSCs) in the presence of percent-level H2S. The method uses a gas chromatograph (GC) coupled with a multicollector inductively coupled plasma mass spectrometer (MC-ICPMS). The GC, equipped with a gas inlet and a valve that transfers the H2S to a thermal conductiv...
متن کاملAmount-dependent isotopic fractionation during compound-specific isotope analysis.
The performance of a gas chromatography-combustion-isotope ratio mass spectrometry system (GC-C-IRMS) with respect to the dependence of delta(13)C values on the amount of sample is presented. Particular attention is paid to the localization of the amount-dependent isotopic fractionation within the system. Injection experiments with varying amounts of gases (CO(2), n-hexane, and toluene) reveale...
متن کاملEnantiomeric separation and compound specific stable isotope analysis
11 A fast and simple method for authenticating raspberry flavors from food products was developed. The two enantiomers 12 of the compound (E)-α-ionone from raspberry flavor were separated on a chiral gas chromatographic column. Based on 13 the ratio of these two enantiomers the naturalness of a raspberry flavor can be evaluated due to the fact that a natural 14 flavor will consist almost exclus...
متن کاملMeasuring carbon isotope ratios of microphytobenthos using compound-specific stable isotope analysis of phytol
Carbon stable isotope analysis is one of the most common methods for validating theories about the role microphytobenthos (MPB) plays in estuarine food webs. However, difficulties extracting MPB from sediments to determine a pure isotope signature have hampered such studies. We have developed compound-specific isotope analysis (CSIA) of phytol δ13C (δCphytol) as an accurate proxy for δ 13C of b...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Chemosphere
سال: 2021
ISSN: ['0045-6535', '1879-1298']
DOI: https://doi.org/10.1016/j.chemosphere.2020.129232