A study of the excretion of organic antimonials using a polarographic procedure

Abstract

I943 other mixtures, e.g. of C22H4402 and C24H4802, which have been examined [Chibnall, Piper & Williams, 1936], show too many irregularities to be used for direct comparison. Some estimate of the nature of the impurities present may, however, be made by correlating the X-ray measurements with the general observations made by Chibnall et al. [1936] on the behaviour of fatty acid mixtures. For this purpose measurements had to be made of both the B and C polymorphic modifications, the X-ray photographs usually being taken of samples pressed lightly on to glass slides. A. The original preparation, when recrystallized from acetone, showed X-ray lines corresponding to the C modification alone. On recrystallization from benzene and from acetic acid, preparations were obtained, both of which showed lines due to B and C modifications on the same photograph. Such behaviour was noted by Piper and co-workers [Chibnall et al. 1936] in the binary mixture containing 2.5-10% and 80-90 % of the lower constituent. Here the C spaci#g is slightly lower, the B spacing slightly higher than, the best values for pure C22H4402. Both these types of spacing change may be due to mixture of a small quantity of C20H4002, say 2-5-10%, with C22H4402, but it seems very probable that the fraction still contains traces of other acids, particularly C24H4802. IIIR5. This fraction, when recrystallized from methanol-ethyl acetate, showed the B spacing alone. While the spac-ings. both of this, and of the methyl ester, are intermediate between those of C22H4402 and C24H4802, the data do not fit very well with the observations that have been made on mixtures of synthetic C22114402 and C24H4802, so that the mixture is presumably more complex. Table 6. X-ray mea8urementB Acid M.P. Methyl ester fraction 0 C. B spacing C spacing spacing A 77-5 536 47.7-III R5 81*9 56*5 61-0 Compare C2OH4002 73-5 48-45 44*15 52-3 CS2H22 79.95 52*95 48*3 57-02 /SUMMARY 1. The isolation of behenic acid from refined mona wax is described. 2. The results of X-ray crystallographic examination of the product, by C. H. Carlisle & D. Crow-foot, are reported. They confirm the conclusion that the isolated product consists largely of behenic acid. The authors wish to thank Mr J. P. Wilson for his assistance during some of the distillations and Mr J.