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In this article, ultrasonic-assisted cloud point extraction (UA-CPE) was used to the preconcentration of trace Ag(I) and Cd(II) in dried nut and vegetable samples. After ion association of Ag(I) and Cd(II) ions with 3,7-diamino-2,8-dimethyl-5-phenyl-phenaziniumchlorid (Safranin T) in the presence of excess potassium iodide (KI) at pH 6.0, the ternary complexes formed were quantitatively extracted into a micellar phase of poly(ethyleneglycol-mono-p-nonylphenylether) (PONPE 7.5) and then determined by flame atomic absorption spectrometry (FAAS). The matrix effects of possible some interfering ions on the method recovery and tolerance limits were also investigated. Under the optimized reagent conditions, the method was linearly dependent on the analyte concentrations in the range of 0.08-90 and 3-250 μg L −1 with limits of detection of 0.02 and 0.9 μg L −1 for Ag(I) and Cd(II), respectively. The reproducibility as the percent relative standard deviations (RSDs %) (0.5, 5.0, and 25 μg L −1 for Ag(I) and 15, 30, and 100 μg L −1 for Cd(II), n = 6) was lower than 3.6 % for both analytes. The accuracy of the method was controlled by analysis of two certified samples (SRM 1573a Tomato leaves and SRM 1643e Trace elements in waters) as well as recovery studies from spiked samples. It has been observed that the results obtained are in a good agreement with the certified values at confidence interval of 95 %. The method was successfully applied to determination of Ag(I) and Cd(II) in several dried nut and vegetable samples by FAAS after separation/preconcentration with UA-CPE.

In this work, a simple and versatile ultrasound-assisted extraction (UAE) procedure, which provides high separation efficiency for bisphenol A (BPA), was developed for its indirect determination in beverages in contact with plastic containers by flame atomic absorption spectrometry (FAAS). The method is based on charge transfer reaction, in which BPA reacts with Cu(II) in alkaline tartrate solutions of pH 8.0 to produce Cu(I), which reacts with ion-pairing reagent, Promethazine, being a phenothiazine derivative (PMZ), in the presence of cetyl trimethylammonium bromide (CTAB). For the indirect determination of BPA using FAAS, the change in signal of Cu(II) depending on BPA concentration was investigated in detail. At optimal conditions, the analytical features of the method were obtained as follows; linearity ranges of 1.5-100 µg L-1 for direct aqueous calibration solutions and 3-125 µg L-1 for matrix matched calibration solutions; the limits of detection and quantification of 0.47 and 1.56 µg L-1 ; sensitivity enhancement and pre-concentration factors of 135 and 150, respectively. The method accuracy was validated by repeatability/reproducibility precision studies using standard addition method. As the last, the method was successfully applied for determination of BPA in selected samples. BPA as a food stimulant was detected in ranges of 2.70-3.80 µg L-1 in waters and 3.10-5.40 µg L-1 in milk products while its levels changed in ranges of 6.40-7.70 and 4.30-19.2 µg L-1 in beverages with and without alcohol. These levels were highly lower than the specific migration limit set by European Union.