CONTINUOUS-FLOW THIN-LAYER HEADSPACE (TLHS) ANALYSIS .2. SPECTROPHOTOMETRIC DETERMINATION OF VOLATILE ORGANIC HALOGENS (VOX) IN WATER

A new method is presented for the continuous determination of volatile organic halogen (VOX) in water. It is based on isolation of the volatile analytes (VA) from the aqueous sample by means of the thin-layer headspace (TLHS) technique, mineralization of the VA in an empty quartz tube, and subsequent determination of the formed halogen ions absorbed in a liquid sorbent by means of an indirect spectrophotometric method using the iron thiocyanate complex. The method proved to be selective; no interferences of other elements at the levels encountered in practice have been found. Due to this fact and to the sensitivity of the method (of the order of 0.1-mu-g/g) it is well suited for the determination of the VOX level in waste waters. The theory of the continuous flow TLHS analysis has been further developed. The results of mathematical analysis of the derived general equation for the concentration of the VA in the liquid sorbent are presented.