Zinc by paper Chromatography

The above methods are concerned primarily with unused lubricants and consequently a report by Goodwin and Begeman^6 are of interest. This  article  describes a methods  of  tracing  Zinc dialkyldithiophosphate  decomposition  in axle lubricants by  paper  chromatography. For  the  purpose, a  sample  of the oil  was  allowed to  soak  into  a sheet  of filter paper after  which  the  paper  was suspended  in  a  chromatogram   above  a  developing  solvent. About 1/8 inch of the lower edge of the paper was immersed in the solution until the solvent front had traveled to within 1 ½ inches from the top.  Following this treatment, the paper was dried. Since  the  zinc  compounds  in the developed chromatograms  are  colorless, a colored  zinc  derivative  was formed  by spraying  the paper with a 0.05  per cent  solution of  diphenylthiocarbozone  (dithiozone)  in  chloroform. This formed a purplish red zinc dithioozonate. Any  excess  dithiozone  was  removed  by  immersing  in a weak  ammonium  hydroxide  solution and then  washing  with water. The  red  color  fades over  a period of days  but may be  photographed  with  color  films to give  a permanent record. The intensity of the color indicates the relative amount of zinc present. Thus, the intensity of colors in tests decreased considerably in the interval of road mileage from 2,006 to 5,144.

Future Trends

If the business of providing proper lubrication for  gears and transmissions were a  static one, people  would  lose  interest in it, and  there  would  be no  purpose  in this volume. However, as indicated by the just preceding, there are problems in connection with gear lubrication and gear lubricants. While  the immediate reaction  to a complaint  or a  problem  of this  sort  is to  blame  the lubricant, it  should be  again  pointed  out  that  perhaps  only  ten  per cent  of   such  complaints are due to  deficiencies  in either  the lubricant or the  application. In spite of this , the  industry  does  have problems and since they  will not  always solve  themselves, it  is necessary  to give  thought  to the  future  when  solution of  the  immediate  problems will be possible  but new  ones  will be  confronted.

Since a little  adversity is good  for the soul, these  problems stimulate  thought  and are the  cause  of many  improvements  and  advancements  in   all industry. In the lubrication of   gearing, the problems do not always take the form of complaints but often of suggestions. Whatever the form,  such  questions do indicate that  modification of  not  only  present  products  but  also  present  thought may be  necessary if the  lubrication industry  is  to  play  a part  in continually improving  the world.

No matter how  did  wild  dreams about providing  different  or better lubricants for gears may  be,  they  would  come  to naught  if  practical considerations are not  kept  in mind. These  include  the economy  of   the suggestion,  the  availability  of  the  necessary  components of the  composition, the  ease of  application, compatibility  with other  materials, and  acceptance  by  other industries  and  by the public. Any or all of these factors may change with time; hence, it is well to dream.