A flow injection method was studied for the determination of chloroform in water. The method is based on the following two reactions.
(1) Reimer-Tiemann reaction, which is well known that phenol reacts with chloroform in alkaline solution to form salicylaldehyde.
(2) The formation of beryllium complex with the Schiff base which is formed from salicylaldehyde and ethylenediamine.
A solution containing 5 % of phenol and 4 % of sodium hydroxide is pumped as a carrier stream (0.58ml/min), into which 125μl of sample solution is injected. This allows the formation of salicylalde-hyde in a heating coil (5 m, 85°C) . The salicylaldehyde reacts with ethylenediamine and beryllium in the reagent stream (0.35 ml/min) through a cooling coil (2 m, 0°C), to form beryllium-Schiff base complex. The fluorescence intensity of the complex excited at 340 nm is measured at 440 nm. The linearity of calibration curve was good, and the relative standard deviation in respective five determinations of 5 mg/l of chloroform was 0.80%. A routine sampling rate of 15 determinations per hour can be achieved with this method. This method cannot be applied to the determination of chloroform in drinking water due to the lack of its sensitivity, but seems to be useful for the monitoring of water sample containing ppm level of chloroform.
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