/57/ 96. ^ destroyed at 100°C at pH 7 in 5 hours. /jS/ No destruction in 1^ HCl in 7 hours at 100° C. 

 /59/ 100^ destroyed in I5 minutes at pH 9 at 100°C. /UO/ Unstable in presence of air. /hi/ Heat sta- 

 bility a function of pH and nature of buffer. /kZ/ Isomerization of double bonds occurs in 7 minutes 

 in 20^ KOH at 178° C, although these vitagens appear to be less labile at lower temperatures. /Uj/ Sen- 

 sitive to light and air oxidation, /hh/ Almost no destruction of multiple unsaturated fatty acids by 

 heat, unless in strongly alkaline solution (cf. Fn 14-2). A5/ Most amino acids undergo racemization in 

 alkaline solutions, but they are otherwise stable. A6/ Modified by UV. A7/ Tryptophan completely 

 destroyed by hot 2C^ HCl in 12 hours; threonine undergoes slight destruction. Only peirtial destruction 

 on refluxlng with 2.5 N H2S0i^ for 6 hours. A8/ Oxidation of sone inorganic salts of lower valence 

 states to higher valence states when exposed to atmospheric oxygen, i.e., ferrous to ferric iron. 



141 



