ABSTRACT
A s e x p l a i n e d at the b e g i n n i n g of C h a p t e r 15, this t echn ique differs f r o m static headspace ana lys i s i n that i n d y n a m i c headspace ana lys i s the wa te r s amp le is p u r g e d w i t h an iner t gas a n d the vo la t i l e organics r e m o v e d a n d adsorbed o n to a s o l i d , s u c h as Tenax G C or act ive ca rbon . T h e adso rbed organics are t h e n d e s o r b e d i n a s m a l l v o l u m e of o rgan ic so lven t , u s u a l l y c h l o r o f o r m or c a r b o n d i s u l p h i d e w h i c h is subsequen t ly a n a l y s e d b y gas ch romatography . A l t h o u g h capable of a c h i e v i n g v e r y h i g h concen t ra t ion factors, a d i s a d v a n t a g e of this technique is that the o rgan ic so lven t a n d i m p u r i t i e s t he re in c a n cause dif f icul t ies at the gas c h r o m a t o g r a p h i c stage of the ana lys i s . Static headspace ana lys i s is so lvent less i n that the aqueous s a m p l e is hea ted to say 3 0 ° C i n the presence, usua l ly , of ino rgan ic salts w h i c h h e l p to d r i v e the organics in to the iner t gas-f i l led headspace above the sample . Por t ions o f the headspace gas are then w i t h d r a w n b y s y r i n g e for gas ch roma tog raph i c ana lys is . T h i s headspace analys is , u n l i k e p u r g e a n d t rap, is a static m e t h o d .
