Multiwavelength monitoring of photofragment fluorescence after 193 nm photolysis of NaCl and NaOH. Application to measuring the sodium species released from coal at high temperatures

Journal Article · Tue Feb 14 23:00:00 EST 1995 · Analytical Chemistry (Washington); (United States)

DOI:https://doi.org/10.1021/ac00100a004· OSTI ID:6601280

Chadwick, B L; Domazetis, G ^[1]; Morrison, R J.S. ^[2]

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1. Herman Research Lab., Mulgrave (Australia)
2. Monash Univ., Clayton (Australia)

Excimer laser photodissociation of gas-phase NaCl and NaOH, and monitoring of the subsequent Na photofragment fluorescence, are used to determine the concentration of the species in coal-derived gaseous environments. Detection limits lower than 1 ppb of NaCl have been achieved under atmospheric conditions using 193 nm photodissociation. It is shown that monitoring two Na emission wavelengths (at 819 and 589 nm) allows speciation between NaOH and NaCl in the gas phase. In particular, emission from the Na 3[sup 2]D levels (at 819 nm) has been unambiguously attributed to photodissociation of NaOH. This emission results from hot-band absorption of the excimer laser, and thus its intensity is temperature dependent and weaker than 3[sup 2]P (589 nm) emission. The technique has been applied to the detection of NaCl and NaOH released during the pyrolysis and gasification of samples of Loy Yang (Australian brown) coal. 13 refs., 9 figs., 1 tab.

• OSTI ID: 6601280
• Journal Information: Analytical Chemistry (Washington); (United States), Journal Name: Analytical Chemistry (Washington); (United States) Vol. 67:4; ISSN 0003-2700; ISSN ANCHAM
• Country of Publication: United States
• Language: English

Related Subjects

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37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
400201 -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
ALKALI METALS
BROWN COAL
CARBONACEOUS MATERIALS
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
COAL
COAL GASIFICATION
DECOMPOSITION
DISSOCIATION
ELEMENTS
EMISSION SPECTRA
ENERGY SOURCES
FLUORESCENCE
FOSSIL FUELS
FRAGMENTATION
FUELS
GASIFICATION
HALIDES
HALOGEN COMPOUNDS
HYDROGEN COMPOUNDS
HYDROXIDES
LUMINESCENCE
MATERIALS
METALS
OXYGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PHOTOLYSIS
PYROLYSIS
QUANTITATIVE CHEMICAL ANALYSIS
SODIUM
SODIUM CHLORIDES
SODIUM COMPOUNDS
SODIUM HYDROXIDES
SPECTRA
THERMOCHEMICAL PROCESSES