Gas chromatography in the quality control of highly refined naphthalene

Journal Article · Thu Jan 01 04:00:00 EST 1981 · Coke Chem. USSR (Engl. Transl.); (United States)

OSTI ID:6290016

Mariich, L I; Ganzha, L M

The objectives in the present investigation were: to develop a chromatographic procedure for impurity determinations on grade I naphthalene (cp less than or equal to 79.8/sup 0/C) derived from coal tar made in Southern and Eastern plants and used at the Bereznikovsk Chemical Combine to make Cleve's acids; to ascertain the chromatgraphic conditions required for separating the critical pair of constituents, viz., naphthalene and thionaphthene (nominal substance and chief impurity), with a view to extending the use of the chromatographic procedure to the quality control of superior-grade naphthalene (cp greater than or equal to 80/sup 0/C); and to compare the various methods of determining naphthalene purity, viz., from the cp, from the cp depression index and by gas chromatography. It was concluded that: (1) The gas-liquid chromatographic procedure can attain separation criteria of K less than or equal to 0.5 for the nominal substance/impurity pair (naphthalene/thionaphthene) and can determine impurity contents down to 0.3% in naphthalene with a cp greater than or equal to 80/sup 0/C. The gas adsorption procedure raises the separation criterion K to 1.60 and can determine thionaphthene contents down to 0.01% in naphthalene with a cp up to 80.28/sup 0/C. (2) Naphthalenes with a cp of 79.8/sup 0/C and a ..delta..t index of 2.0 to 2.3/sup 0/C can contain impurities over a wide concentration range, viz., 0.50 to 0.90 wt % thionaphthene, 0.4 to 0.06 wt % ..beta..-methynaphthalene and 0.01 to 0l03 wt % indene. (3) Of the three methods of evaluating naphthalene purity - cp, cp depression and chromatographic analysis - the last-named is the most sensitive. (4) There is no correlation between the cp and the cp depression index on the one hand and the total impurity content found by chromatographic analysis on the other hand.

• OSTI ID: 6290016
• Journal Information: Coke Chem. USSR (Engl. Transl.); (United States), Journal Name: Coke Chem. USSR (Engl. Transl.); (United States) Vol. 7; ISSN COKCA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010500* -- Coal
Lignite
& Peat-- Products & By-Products
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
AROMATICS
CHROMATOGRAPHY
COAL TAR
CONDENSED AROMATICS
CONTROL
GAS CHROMATOGRAPHY
HYDROCARBONS
NAPHTHALENE
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PROCESSING
QUALITY CONTROL
SEPARATION PROCESSES
TAR