DEVELOPMENT OF A CLEAN SEAWATER SAMPLER F OR THE DETERMINATION OF CHLOROFLUOROCARBONS

A clean seawater sampler for the determination of chlorofluorocarbons (CFCs) is described. The sampler consists of a sample-drawing section and a sample storage tube with two 3 way valves at both tube ends. Two plastic syringes in the sample-drawing section draw, by the force of a helical stainless-steel spring, about 100 ml of water (a volume thre e times of that of the sample tube). The sample tube is directly conne cted to a gas stripping-concentration system for the determination of dissolved CFCs. The water inside the sample tube is prevented from con tacting the ambient air during this procedures. The sampler was used i n analyzing North Pacific water for CFCs. The concentrations of CFCs i n the water collected with this sampler was lower than that of 1.7 lit er Niskin bottles. The concentrations of CFCs in water collected below 1500 m, where the radiocarbon age is estimated to be about 1500 years , were below the detection limit.