Volume 1

Chemical technology and analysis of oils, fats, and waxes / by J. Lewkowitsch.

  • Julius Lewkowitsch
Date:
1904
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Chemical technology and analysis of oils, fats, and waxes / by J. Lewkowitsch. Source: Wellcome Collection.

    49/454 (page 29)
    may be regarded as a mixed glyceride of oleic acid, stearic acid, hydrogen sulphate, and hydroxystearic acid,1 having the formula C3H5[0. C18H330]. [0. C18H34(S04H). 0]. [0 . ClgH.u(0H)0]. This reaction is made use of in the manufacture of Turkey red oils (chap. xv.). At a temperature exceeding 100° C. concentrated sulphuric acid reacts energetically Avith all oils and fats, hydrolysing the fats into glycerol and sulpho-compounds of the fatty acids. The latter are decomposed into sulphuric acid and fatty acids on steaming. On this leaction is based the $<acid saponification” process emploA’ed in the candle industry (see chap. xv.). Concent') ated nitric acid attacks the oils and fats, acting on them a iolently and Avith copious evolution of red fumes. Hot dilute nitric acid oxidises the oils and fats gradually. Fahrion2 concludes fiom some experiments that all glycerides of unsaturated acids Avhen acted on Avith nitric acid give rise to the formation of hydroxy acids, which on further treatment Avith nitric acid are said to be converted into nitro-derivatives of hydroxy acids. This statement stands in need of confirmation. On treatment Avith nitrous add the non-drying oils become solid or acquire the consistency of butter according to the proportion of triolein (trierucin, etc.) they contain, the triolein (trierucin etc.) being converted into the solid isomeride trielaidin (tribrassidin etc ) (cp chap. vii. p. 301). Drying oils, on the other hand, when binnlarly treated, remain liquid. Lidoff3 states that their specific gravity increases, as also their viscosity and saponification value Avhereas the iodine and the Helmer values decrease. All oils after treatment with nitrous acid, contain, according to the same author nitrogen varying in amount from 1 to 2'5 per cent. These substances may be i educed, yielding new compounds, which probably contain the NH2 group. The free unsaturated acids yield no such com- pounds. These statements stand in need of confirmation.4 Fuming nitric acid, in presence of concentrated sulphuric acid reacts Avith linseed oil and castor oil to form “ nitrated ” oik the natui e of which has not been investigated yet, although they have found technical application (cp. chap. xv. “ Nitrated Oils”) ^ Chlorin,! and bnmirn act oi, fats with evolution of hydrochloric and hydrobromic acids respectively, glycerides of chloro- or brlo- “of ATLSri, b * ;;XTr^hamhei with Iodine does not yield substitution products, and is but slowlv absorbed when mixed w.th an oil or fat. The dissolving power of diis 1 Geitel, Jour,, Soe. Chen Ind 1888. 219 ; W,/. Ckeviie, 1888 [53] 218 Aeit.f. ungew. Chemie, 1891, 74 zio. 4 r, f0,VL Soc- 1893, Abstracts ii. 559. P' Lcwkowitscli, Jahrh. d. Chemie, 6 (1896), 373