ABSTRACT
Techniques d i s cus sed i n chapters 20 to 29 are conce rned w i t h the p reconcen t ra t ion of either s ingle cat ions or, i n some cases, w i t h severa l cat ions. E n o u g h has been s a id i n these chapters to demonst ra te the app l i ca t ions of these va r ious techniques . There is howeve r , m u c h m o r e p u b l i s h e d w o r k ava i l ab l e o n the a p p l i c a t i o n s of p r e c o n c e n t r a t i o n techniques w h i c h h a n d l e severa l cat ions as o p p o s e d to a s ing le ca t ion . These m e t h o d s are not d i scussed i n the p r e c e d i n g chapters b u t are s u m m a r i s e d b r i e f l y b e l o w . S u m m a r i e s of fur ther m e t h o d s for p reconcen t ra t ion of mul t i ca t ions i n n o n sal ine waters , sea wate rs a n d potable waters are g i v e n , respectively, i n Tables 30.1 to 30.3.
