A new and practical column separation/preconcentration method for the determination of Pt in environmental samples is proposed. The method has been successfully applied to the determination of Pt in a tunnel dust sample with isotope dilution ICP-MS. A key to its success is an anion-exchange separation of Pt from Hf.

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An octadecylsilylsilica (C18) column dynamically coated with methyltricaprylylammonium chloride (C18-Aliquat 336) was examined for the preconcentration of trace amounts of Zn in water samples. Zinc was quantitatively retained on the column from an HCl solution at between 0.5 and 3 mol dm-3, or seawater acidified with HCI, ranging from 0.5 to 1.0 mol dm-3. The retention capacity of the Cls-Aliquat 336 for zinc was about 50 µmol g-' from a 1 mol dm3 HCl solution. The Zn retained on the column was completely eluted with 3.5 ml of 0.1 mol dm3 nitric acid, and was directly determined by graphite-furnace atomic absorption spectrometry. The precision and accuracy of the present method were demonstrated by analyzing certified reference materials, such as Coastal Seawater (CASS-2) and Riverine Water (SLRS-3). The total procedural blank was 1.9±0.4 ng for Zn. The detection limit (3u of the blanks) was 2.4 ng dm-3 for Zn based on a 125-fold concentration of a 500-ml sample.

Recently, acid rain has become a grave environmental problem. The authors realized artificial acid rain with any electric conductivity σ and pH value by a combination of dilute sulfuric acid and seven kinds of salts based on the chemical analysis of the ionic ingredient of rainwater. In this paper, a propagation of a streamer discharge on the surface of artificial acid rain is investigated in detail by using a high‐speed Schlieren method and a current‐measuring system by LED. The results obtained may be summarized as follows: A flashover voltage Vf of rainwater decreases gradually with increasing the σ and an effect of the Vf on the pH cannot be seen obviously in this experimental condition; On the propagation of the streamer discharge on the surface of artificial acid rain. In case of rain which has nearly the same pH and the different σ, the propagation length ld of streamer‐like density changes becomes larger as the σ is made larger; In case for rain which has nearly the same σ and the different pH, a remarkable difference cannot be seen in a propagation figure and a t‐ld characteristic of the streamer‐like density changes, and in a current waveform.