Figure 18. — Chromatogram of 

 cottonwood treated with 

 5 percent sodium hydroxide 

 (upper) and 5 percent zinc 

 chloride (lower) (see 

 figure 7 for peak identi- 

 fication) . 



O / 



8 /min. 



Isothermal 



50 



210 



Temperature ( C.) 



27 



