Neutron activation analysis of environmental materials

Kolesov, G.M.

doi:10.1039/an9952001457

Cited by 11 publications

(2 citation statements)

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“…Therefore, distillation appears to improve agreement between fluorometry and NAA, though this may be coincidence, as NAA analysis has several unresolved issues with calculation accuracy. We stress that although NAA is of appropriate sensitivity to measure parts per million level N concentrations (e.g., Kolesov, 1995), there are complicating issues. Neutron bombardment can also create 14 C via reaction with 17 O, with a theoretical apparent N contribution in a sample with 40 % O of 18 ppm, though analysis of a synthetic Al 2 O 3 doped with 20 % 17 O suggests the actual effect may only be 6 ppm (Shukla et al, 1978).…”

Section: Reproducibility and Reproduction Of Published Valuesmentioning

confidence: 99%

Measurement of geologic nitrogen using mass spectrometry, colorimetry, and a newly adapted fluorometry technique

et al. 2017

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Abstract. Long viewed as a mostly noble, atmospheric species, recent work demonstrates that nitrogen in fact cycles throughout the Earth system, including the atmosphere, biosphere, oceans, and solid Earth. Despite this new-found behaviour, more thorough investigation of N in geologic materials is limited due to its low concentration (one to tens of parts per million) and difficulty in analysis. In addition, N can exist in multiple species (NO3−, NH4+, N2, organic N), and determining which species is actually quantified can be difficult. In rocks and minerals, NH4+ is the most stable form of N over geologic timescales. As such, techniques designed to measure NH4+ can be particularly useful.We measured a number of geochemical rock standards using three different techniques: elemental analyzer (EA) mass spectrometry, colorimetry, and fluorometry. The fluorometry approach is a novel adaptation of a technique commonly used in biologic science, applied herein to geologic NH4+. Briefly, NH4+ can be quantified by HF dissolution, neutralization, addition of a fluorescing reagent, and analysis on a standard fluorometer. We reproduce published values for several rock standards (BCR-2, BHVO-2, and G-2), especially if an additional distillation step is performed. While it is difficult to assess the quality of each method, due to lack of international geologic N standards, fluorometry appears better suited to analyzing mineral-bound NH4+ than EA mass spectrometry and is a simpler, quicker alternative to colorimetry.To demonstrate a potential application of fluorometry, we calculated a continental crust N budget based on new measurements. We used glacial tills as a proxy for upper crust and analyzed several poorly constrained rock types (volcanics, mid-crustal xenoliths) to determine that the continental crust contains ∼ 2 × 1018 kg N. This estimate is consistent with recent budget estimates and shows that fluorometry is appropriate for large-scale questions where high sample throughput is helpful.Lastly, we report the first δ15N values of six rock standards: BCR-2 (1. 05 ± 0. 4 ‰), BHVO-2 (−0. 3 ± 0. 2 ‰), G-2 (1. 23 ± 1. 32 ‰), LKSD-4 (3. 59 ± 0. 1 ‰), Till-4 (6. 33 ± 0. 1 ‰), and SY-4 (2. 13 ± 0. 5 ‰). The need for international geologic N standards is crucial for further investigation of the Earth system N cycle, and we suggest that existing rock standards may be suited to this need.

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Section: Reproducibility and Reproduction Of Published Valuesmentioning

confidence: 99%

Measurement of geologic nitrogen using mass spectrometry, colorimetry, and a newly adapted fluorometry technique

et al. 2017

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“…Environmental samples (coal, oil, ash, dust, soil, sludge, sediment) are frequently characterized by INAA (32,34,36,37,51), which can be directly applied even to samples of kilogram size (52,53). The aim of the analyses is often pollution control, which requires monitoring of a wide variety of pollutants, as the cross-influence of many elements is well recognized.…”

Section: Applicability and Actual Casesmentioning

confidence: 99%