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A novel surfactant-assisted dispersive liquid-liquid microextraction (SADLLME) based on solidification of floating organic drop (SFO) combined with high-performance liquid chromatographyultraviolet detection (HPLC-UV) has been proposed for extraction and determination of amphetamine (AM) and methamphetamine (MA) in urine samples. 1-undecanol and sodium dodecyl sulfate (SDS) were used as extracting solvent and disperser, respectively. Face-centered central composite design (FCCCD) was used for optimization of several factors affecting extraction recovery. The optimal conditions were pH ¼ 6.4, volume of extracting solvent V ¼ 31.0 mL, 0.08 CMC as surfactant concentration, and the amount of NaCl for ionic strength was 0.3% (W/V). The limits of detection (LODs, S/N ¼ 3) of the extraction method were 2 for AM and 3 mg L À1 for MA, with the enrichment factors (EFs) of 56 and 48 folds, respectively. The relative standard deviation (RSD %) for n ¼ 3 was below 5.6% and a good linearity (R 2 > 0.991) in the range of 10-2000 mg L À1 was observed. The application feasibility of SFO-SADLLME-HPLC-UV in real sample was investigated by analyzing different real samples and satisfactory results were obtained.

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A simple and reliable method for the extraction and determination of trace amounts of copper(II) ions using activated carbon (AC) impregnated by a new Schiff base 5-[(4-heptyloxyphenyl)azo]-N-(4-propyloxyphenyl)-salicylaldimine (HPPS) and atomic absorption spectrometry is presented. Recovery efficiency and the influence of pH value, volume of sample solution, effect of different eluents, and interfering ions were evaluated. The limit of detection (3σ) was 2.62 ng•mL -1 and the relative standard deviation (n＝10) was 1.5%. Under optimum conditions, the copper ions were concentrated 25 fold using 250 mL of sample solution and 10 mL of eluent. This procedure has been successfully applied to the determination of copper in different water samples.

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