Comparison of the purity of samples of organic solvents by ultraviolet spectrophotometry

Abstract

Studies of the uniformity of different samples of organic solvents by ultraviolet spectrophotometry are described. The procedure used is applicable to the detection of impurities originally present or formed by deterioration and to the study of the effectiveness of purification procedures.Absorption curves are given for n-heptane, 2,2,4-trimethylpentane, cyclohexane, methylcyclohexane, decahydronaphthalene, benzene, carbon tetrachloride, methyl alcohol, ethyl alcohol, ethyl acetate, and dioxane, in two or more grades of purity. The absorption curves of tetrahydronaphthalene, toluene, xylene, chlorobenzene, ethylene dichloride, trichloroethylene, acetone, dimethyldioxane, and carbon bisulfide are discussed briefly. The effect of filtration through silica gel on the ultraviolet absorption of several commercial solvents is shown.

cis,cis-1,5-Cyclooctadiene diepoxide

“…The pentane solution was dried (MgSO,) and concentrated. The ir spectrum of the residue was identical with that of an authentic sample of 9-oxabicyclo [4.2.1] nonane (4). Glpc analysis on a 2-ft 20% SE-30 showed only one component.…”

“…Analytical samples of the individual ketones were obtained by preparative glpc on the same column. The minor component 12 had mp 29.5-32°; ir (KBr) 1700 (vs), 1190 (m), 1140 (w), 1105 (m), 1090 (s), 1060 (m), 1035 (s), 1005 (w), 960 (w), 945 (m), 860 (w), and 760 cm-1 (w); nmr (CCfi) 1.1-2.3 (m, 6 H), 2.4-3.0 (m, 4 ), 4.15-4.65 (bs, 2 H).…”

Acid-base reactions in benzene and other organic solvents: Behavior of bromphthalein magenta with different classes of organic bases

“…For curve A, the maximum in the 33 Tbe autbors are indebted to tbe American Oyanamid 00. for these sam ples. 34 The maximum molar absorbancy index for curve 4 is probably too low (see section IV-5). Ourve 6 was calculated from the data shown as absorbancy curve 4 in fig.…”

“…Ethyl acetate.-A high grade of commercial sol-230 vent was shaken with dilute alkali, washpd, dried, and distilled [34]. Ethyl alcohol.-95-percent alcohol was redistilled [34].…”

Determination of Carbon Disulfide in itsPiperazine Compounds

“…The ultraviolet spectrum of carbon disulfide was reported in 1925 by Bruhat and Pauthenier (14). The characteristic absorption maximum a t about 320 mp lends itself to qualitative (15) identifications. A quantitative spectrophotometric determination of carbon disulfide in carbon tetrachloride has been suggested by Andreev and Gindina In the case of the equimolecular complex of piperazine and carbon disulfide and other carbon disulfide-containing compounds, the carbon disulfide first must be liberated from the parent (16).…”