R. M. Barnes (Ed.): <i>Emission Spectroscopy.</i> Dowden, Hutchinson und Ross, Inc. Stroudsburg, Pennsylvania 1976, distributed by Halsted Press. 548 S., Preis: US $ 38.85.

Witte, Hermann

doi:10.1002/bbpc.19760801140

Cited by 1 publication

(1 citation statement)

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“…High-pressure (80 psi) dry air is supplied to a downstream glass concentric nebulizer (Meinhard TL-HEN-150-A0.1 with ∼ 100 µm ID), which converts the primary liquid water into a fine spray with a nominal droplet size of ∼ 1.5 µm. The concentric nebulizer was introduced in the late 1800s by Guoy (as discussed in Witte and Barnes, 1976) and has commonly been used in inductively coupled plasma mass spectrometry. It has been in use in this system since 2011 and was first shown by Emanuelsson et al (2015) to be useable in ice core CFA-LAS systems.…”

Section: Experimental Systemmentioning

confidence: 99%

Improved methodologies for continuous-flow analysis of stable water isotopes in ice cores

et al. 2017

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Abstract. Water isotopes in ice cores are used as a climate proxy for local temperature and regional atmospheric circulation as well as evaporative conditions in moisture source regions. Traditional measurements of water isotopes have been achieved using magnetic sector isotope ratio mass spectrometry (IRMS). However, a number of recent studies have shown that laser absorption spectrometry (LAS) performs as well or better than IRMS. The new LAS technology has been combined with continuous-flow analysis (CFA) to improve data density and sample throughput in numerous prior ice coring projects. Here, we present a comparable semiautomated LAS-CFA system for measuring high-resolution water isotopes of ice cores. We outline new methods for partitioning both system precision and mixing length into liquid and vapor components -useful measures for defining and improving the overall performance of the system. Critically, these methods take into account the uncertainty of depth registration that is not present in IRMS nor fully accounted for in other CFA studies. These analyses are achieved using samples from a South Pole firn core, a Greenland ice core, and the West Antarctic Ice Sheet (WAIS) Divide ice core. The measurement system utilizes a 16-position carousel contained in a freezer to consecutively deliver ∼ 1 m × 1.3 cm 2 ice sticks to a temperature-controlled melt head, where the ice is converted to a continuous liquid stream and eventually vaporized using a concentric nebulizer for isotopic analysis. An integrated delivery system for water isotope standards is used for calibration to the Vienna Standard Mean Ocean Water (VSMOW) scale, and depth registration is achieved using a precise overhead laser distance device with an uncertainty of ±0.2 mm. As an added check on the system, we perform inter-lab LAS comparisons using WAIS Divide ice samples, a corroboratory step not taken in prior CFA studies. The overall results are important for substantiating data obtained from LAS-CFA systems, including optimizing liquid and vapor mixing lengths, determining melt rates for ice cores with different accumulation and thinning histories, and removing system-wide mixing effects that are convolved with the natural diffusional signal that results primarily from water molecule diffusion in the firn column.

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Section: Experimental Systemmentioning

confidence: 99%