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A sensitive, selective and rapid method for the determination of palladium based on the rapid reaction of palladium(II) with 2-(2-quinolylazo)-5-diethylaminobenzoic acid (QADEAB) and the solid phase extraction of the Pd(II) -QADEAB chelate with a reversed phase polymer-based C18 cartridge was developed. In the presence of 0.05 - 0.5 mol/L of hydrochloric acid solution and cetyl trimethylammonium bromide (CTAB) medium QADEAB reacts with palladium(II) to form a violet complex with a mole ratio 1:2 (palladium to QADEAB). The chelate was enriched by solid phase extraction with a reversed phase polymer-based C18 cartridge. An enrichment factor of 200 was obtained by elution of the chelate form the cartridge with the minimal amount of isopentyl alcohol. The molar absorptivity of the chelate in the isopentyl alcohol medium was 1.43?105 L mol-1 cm-1 at 628 nm. Beer?s law was obeyed in the range of 0.01-1.2 ?g/mL. The relative standard deviation for eleven replicate samples at the 0.2 ?g/L level was 2.18 %. The attained detection limit amounted to 0.02 ?g/L in the original samples. This method was applied to the determination of palladium in environmental samples with good results.

As a conventional method of compensating the nonlinear distortion in OFDM (orthogonal frequency division multiplexing), LCP‐COFDM (linearized constant peak‐power coded OFDM) has been proposed. In LCP‐COFDM, however, the signal power is reduced by the linear compression (constant peak amplitude) process, which degrades the noise immunity and degrades the BER (bit error rate) characteristic. Consequently, this paper proposes a nonlinear distortion compensation scheme in which the BER is improved by combining LCP‐COFDM with the partial transmit sequence. As a result of performance evaluation by computer simulation, it is shown that the proposed method can improve the BER with nearly the same out‐band radiation reduction as conventional LCP‐COFDM. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 87(6): 34–42, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.10129

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