scholarly journals Calibration bias of experimentally determined chlorine isotope enrichment factors: the need for a two-point calibration in compound-specific chlorine isotope analysis

2016 ◽  
Vol 31 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Karin A. Ebert ◽  
Christine Laskov ◽  
Martin Elsner ◽  
Stefan B. Haderlein
Keyword(s):  
Isotope Analysis ◽  
Enrichment Factors ◽  
Isotope Enrichment ◽  
Chlorine Isotope

scholarly journals Exploring the Utility of Compound-Specific Isotope Analysis for Assessing Ferrous Iron-Mediated Reduction of RDX in the Subsurface

2020 ◽  
Author(s):  
Yiran Tong ◽  
Matthew J. Berens ◽  
Bridget A. Ulrich ◽  
Jakov Bolotin ◽  
Jennifer H. Strehlau ◽  
...  
Keyword(s):  
Groundwater Contamination ◽  
Ferrous Iron ◽  
Chemical Reduction ◽  
Isotope Analysis ◽  
Enrichment Factors ◽  
Isotope Enrichment ◽  
Compound Specific Isotope Analysis ◽  
A Site ◽  
Mediated Reduction

This work determines isotope enrichment factors for RDX during reduction by iron minerals. The values determined are used to assess the transformation of RDX at a site with groundwater contamination and in laboratory column reactors simulating in situ chemical reduction treatment.

scholarly journals Exploring the Utility of Compound-Specific Isotope Analysis for Assessing Ferrous Iron-Mediated Reduction of RDX in the Subsurface

2020 ◽  
Author(s):  
Yiran Tong ◽  
Matthew J. Berens ◽  
Bridget A. Ulrich ◽  
Jakov Bolotin ◽  
Jennifer H. Strehlau ◽  
...  
Keyword(s):  
Groundwater Contamination ◽  
Ferrous Iron ◽  
Chemical Reduction ◽  
Isotope Analysis ◽  
Enrichment Factors ◽  
Isotope Enrichment ◽  
Compound Specific Isotope Analysis ◽  
A Site ◽  
Mediated Reduction

This work determines isotope enrichment factors for RDX during reduction by iron minerals. The values determined are used to assess the transformation of RDX at a site with groundwater contamination and in laboratory column reactors simulating in situ chemical reduction treatment.

Stable Chlorine Isotope Analysis of Triclosan using GC-qMS: Method development and applications

2021 ◽  
pp. 104961
Author(s):  
Yi Liu ◽  
Shiyang Liu ◽  
Qiang Wang ◽  
Sasho Gligorovski ◽  
Gan Zhang ◽  
...  
Keyword(s):  
Method Development ◽  
Isotope Analysis ◽  
Chlorine Isotope

scholarly journals Toward Improved Accuracy in Chlorine Isotope Analysis: Synthesis Routes for In-House Standards and Characterization via Complementary Mass Spectrometry Methods

2019 ◽  
Vol 91 (19) ◽  
pp. 12290-12297 ◽  
Author(s):  
Christina Lihl ◽  
Julian Renpenning ◽  
Steffen Kümmel ◽  
Faina Gelman ◽  
Heide K. V. Schürner ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Isotope Analysis ◽  
Chlorine Isotope ◽  
Synthesis Routes ◽  
Improved Accuracy

scholarly journals Stable Isotope Enrichment (Δ15N) in the Predatory Flower Bug (Orius majusculus) Predicts Fitness-Related Differences between Diets

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 255
Author(s):  
Marta Montoro ◽  
Per M. Jensen ◽  
Lene Sigsgaard
Keyword(s):  
Diet Quality ◽  
Isotopic Ratio ◽  
Isotope Analysis ◽  
Mass Rearing ◽  
Isotope Enrichment ◽  
Orius Majusculus ◽  
Food And Feed ◽  
The Difference ◽  
Biochemical Analyses ◽  
Δ15n And Δ13c

Mass rearing of insects, used both as biological control agents and for food and feed, is receiving increasing attention. Efforts are being made to improve diets that are currently in use, and to identify alternative diets, as is the case with the predatory flower bug (Orius majusculus) and other heteropteran predators, due to the high costs of their current diet, the eggs of the Mediterranean flour moth (E. kuehniella). The assessment of alternative diets may include measurements of the predator’s fitness-related traits (development time, weight, etc.), and biochemical analyses such as lipid and protein content in the diet and the insects. However, assessing diet quality via the predator’s fitness-related traits is laborious, and biochemical composition is often difficult to relate to the measured traits. Isotope analysis, previously used for diet reconstruction studies, can also serve as a tool for the assessment of diet quality. Here, the variation in discrimination factors or isotope enrichment (Δ15N and Δ13C) indicates the difference in isotopic ratio between the insect and its diet. In this study, we investigated the link between Δ15N and diet quality in the predatory bug Orius majusculus. Three groups of bugs were fed different diets: Ephestia kuehniella eggs, protein-rich Drosophila melanogaster and lipid-rich D. melanogaster. The isotopic enrichment and fitness-related measurements were assessed for each group. Results show a relation between Δ15N and fitness-related measurements, which conform to the idea that lower Δ15N indicates a higher diet quality.

scholarly journals Tracking host use by bat ectoparasites with stable isotope analysis

2016 ◽  
Vol 94 (5) ◽  
pp. 353-360 ◽  
Author(s):  
Ulalume Hernández-Arciga ◽  
L. Gerardo Herrera M. ◽  
Juan B. Morales-Malacara
Keyword(s):  
Stable Isotope ◽  
Isotope Analysis ◽  
Enrichment Factors ◽  
Host Switching ◽  
Host Use ◽  
Higher Ed ◽  
The Difference ◽  
Anoura Geoffroyi ◽  
Leptonycteris Yerbabuenae ◽  
Host Parasite

We used C and N stable isotopes of nectarivorous bats and their ectoparasites to determine the extent to which parasites depend on the host individual for food. The difference in stable isotope values between parasites and host tissues (Δ13C and Δ15N) was used as a proxy of host use. First, we tested the hypothesis that movement among individual Mexican long-tongued bats (Choeronycteris mexicana Tschudi, 1844) is more likely to occur in winged flies than in mites as indicated by higher host–parasite isotopic Euclidian distance (ED). Second, we tested the hypothesis that ectoparasite species in two coexisting bat species representing the C3 (Geoffroy’s tailless bat, Anoura geoffroyi Gray, 1838) and the CAM (lesser long-nosed bat, Leptonycteris yerbabuenae Martínez and Villa-R., 1940) food chains were monoxenous as indicated by their isotopic values. We also examined Δ13C and Δ15N of individual parasites in relation to 13C and 15N reference enrichment factors as an indication of host switching. In general, flies in C. mexicana had higher ED and wider ranges of individual Δ13C and Δ15N than mites, suggesting that host switching occurred to a larger extent. Most ectoparasites species collected in both coexisting bats were monoxenous, but one fly species appears to be oligoxenous. Individual Δ13C and Δ15N values varied widely in these parasite species, suggesting movements within species hosts.

Stable chlorine-isotope analysis of rock samples: New aspects of chlorine extraction

1998 ◽  
Vol 362 (2-3) ◽  
pp. 261-269 ◽  
Author(s):  
Masaaki Musashi ◽  
Gregor Markl ◽  
Rob Kreulen
Keyword(s):  
Isotope Analysis ◽  
Rock Samples ◽  
Chlorine Isotope

scholarly journals Pesticide fate on catchment scale: conceptual modelling of stream CSIA data

2017 ◽  
Vol 21 (10) ◽  
pp. 5243-5261 ◽  
Author(s):  
Stefanie R. Lutz ◽  
Ype van der Velde ◽  
Omniea F. Elsayed ◽  
Gwenaël Imfeld ◽  
Marie Lefrancq ◽  
...  
Keyword(s):  
Travel Time ◽  
Soil Depth ◽  
Isotope Analysis ◽  
Enrichment Factors ◽  
Conceptual Modelling ◽  
Catchment Scale ◽  
Δ13c Values ◽  
Contaminant Degradation ◽  
Herbicide Degradation ◽  
Closed Systems

Abstract. Compound-specific stable isotope analysis (CSIA) has proven beneficial in the characterization of contaminant degradation in groundwater, but it has never been used to assess pesticide transformation on catchment scale. This study presents concentration and carbon CSIA data of the herbicides S-metolachlor and acetochlor from three locations (plot, drain, and catchment outlets) in a 47 ha agricultural catchment (Bas-Rhin, France). Herbicide concentrations at the catchment outlet were highest (62 µg L−1) in response to an intense rainfall event following herbicide application. Increasing δ13C values of S-metolachlor and acetochlor by more than 2 ‰ during the study period indicated herbicide degradation. To assist the interpretation of these data, discharge, concentrations, and δ13C values of S-metolachlor were modelled with a conceptual mathematical model using the transport formulation by travel-time distributions. Testing of different model setups supported the assumption that degradation half-lives (DT50) increase with increasing soil depth, which can be straightforwardly implemented in conceptual models using travel-time distributions. Moreover, model calibration yielded an estimate of a field-integrated isotopic enrichment factor as opposed to laboratory-based assessments of enrichment factors in closed systems. Thirdly, the Rayleigh equation commonly applied in groundwater studies was tested by our model for its potential to quantify degradation on catchment scale. It provided conservative estimates on the extent of degradation as occurred in stream samples. However, largely exceeding the simulated degradation within the entire catchment, these estimates were not representative of overall degradation on catchment scale. The conceptual modelling approach thus enabled us to upscale sample-based CSIA information on degradation to the catchment scale. Overall, this study demonstrates the benefit of combining monitoring and conceptual modelling of concentration and CSIA data and advocates the use of travel-time distributions for assessing pesticide fate and transport on catchment scale.

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