Determination of alkylnaphthalenes in petroleum fractions by second-derivative ultraviolet spectrophotometry

Abstract

The determination of naphthalene and its alkyl derivatives in aviation turbine fuels (ATF) and other petroleum products is important not only with respect to their performance but also for establishing heart cuts for producing intermediate chemicals for the manufacture of dyes, pesticides and agrochemicals. Normal and second-derivative UV spectra of naphthalenes, biphenyls and other interfering aromatics have been studied with a view to developing a method for determining naphthalene and a-and /3-methyl-, dimethyl-and trimethylnaphthalenes. The characteristic signals due to the substituted naphthalenes were identified in terms of second-derivative signals in a number of straight-run and cracked products of varying nature. Working relationships were derived for each of the naphthalenes in terms of their signal amplitudes. The method was tested on a number of straight-run and cracked petroleum products and it was found that the results calculated by the proposed method are in close agreement with those given by the zero-order UV spectrophotometric method.

Preparation of Micron-Scale Activated Carbon-Immobilized Bacteria for the Adsorption–Biodegradation of Diesel Oil

“…The concentration of diesel oil in water was measured at 256 nm with a UV-visible spectrophotometer (Shimadzu, UV-2550), which was extracted using normal hexane as the solvent [22]. The dehydrogenase and lipase were measured using the colorimetric method [23].…”

Ultraviolet and light absorption spectrometry

“…60, NO. 12, JUNE 15, 1988 • in petroleum fractions (second order) (230), phenol and aniline in wastewater (fourth order) ( 231), atropine sulfate in the presence of sodium metabisulfate and tropic acid (second order) (232) and also in injections, eye drops, and emulsions (second-order) ( 233), bilirubin and hemoglobin in biological samples (first and second order) (234); chlorpromazine and its sulfoxide in pharmaceutical dosage forms (259 and 350 nm, third order) (235), Coenzyme Q10 injections (262 and 287 nm, first order) (236), andd methemoglobin in heparinized blood (650 nm) (first order) (237). Other applications of derivative spectroscopy have been developed for determining the following: oxazepam or phenobarbitone in the presence of dipyridamole (first and second order) (238); identification of purines and pyrimidines (first and second order) (239); quinine-quinidine in Cinchona liquid extract (335 and 294 nm) (first order) (240); A9-tetrahydrocannabinol-cannabinol mixtures (second order) (241); a-, 8-, 7-, and 5-tocopherols in their mixtures (second order) (242); and vitamin A in the presence of its degradation product (288-236 nm, 0.01-0.018 ppm) (first order) (243).…”

Functional group analysis

“…With the use of an internal standard, detection limits in the low nanogram range are obtained (167). Some additional spectroscopic methods involve the determination of aromatics in naphtha, kerosine, and gas oil by infrared spectroscopy (168), the determination of methylnaphthalenes by second derivative ultraviolet spectroscopy (169), and the determination of polycyclic aromatic hydrocarbons in environmental samples by Shpol'skii luminescence spectroscopy (170).…”