Contamination of potentially toxic metals in children's toys marketed in Iran.

Chemical exposure of heavy metals in children is of particular concern. However, using heavy metal-contaminated toys can threaten the life and well-being of children. Therefore, quality control of toys for avoiding children exposure to potentially toxic metals is important. The investigation of potentially toxic metals (arsenic, barium, antimony, cadmium, chromium, mercury, lead, selenium) in toys was performed in present study. A total number of 150 popular cheap priced plastic toy samples were purchased from the eight metropolitan and most visited provinces in Iran and analyzed by atomic absorption spectrophotometer for arsenic, barium, antimony cadmium, chromium, mercury, lead, and selenium. As results showed As, Ba, Cd, Cr, Hg, Pb, Sb, and Se respectively were in the range of 0-0.9 mg/kg, 0.3-5 mg/kg, 0-3.1 mg/kg, 0.04-4.8 mg/kg, 0-0.03 mg/kg, 0.22-11.7 mg/kg, 0-1.2 mg/kg, and 0.03-1.1 mg/kg. Cadmium was higher than the European standard in Kurdistan province. The highest amount of mercury was also observed in Tehran. The highest amount of lead, selenium, and antimony was detected in Qom province. The results showed that all the toxic elements in the collected toys were within the permissible limit. Furthermore, market monitoring is needed to control toys safety on a large scale in metropolitan cities like Qom province.

Taguchi OA16 orthogonal array design for the optimization of cloud point extraction for selenium determination in environmental and biological samples by tungsten-modified tube electrothermal atomic absorption spectrometry.

Orthogonal array design (OAD) was applied for the first time to optimize cloud point extraction (CPE) conditions for Se(IV) determination by electrothermal atomic absorption spectrometry (ETAAS) in environmental and biological samples. Selenium was reacted with o-phenylenediamine to form piazselenol in an acidic medium (pH 2). Using Triton X-114, as surfactant, piazselenol was quantitatively extracted into small volume (about 30 microL) of the surfactant-rich phase after centrifugation. Five relevant factors, i.e. surfactant concentration, pH, ionic strength, equilibrium time and temperature were selected and the effects of each factor were studied at four levels on the extraction efficiency of Se(IV) and optimized. The statistical analysis revealed that the most important factors contributing to the extraction efficiency are ionic strength, pH and percent of surfactant. Based on the results obtained from the analysis of variance (ANOVA), the optimum conditions for extraction were established as: pH 6; vial temperature=50 degrees C; extraction time=7 min and 0.3% (w/v) of Triton X-114. The method was permitted to obtain a detection limit of 0.09 ng mL(-1) and two linear calibration ranges from 0.6 to 1.0 and 1.0 to 80.0 ng mL(-1) Se. The precision (%RSD) of the extraction and determination for the six replicates of Se at 20 ng mL(-1) was better than 3.6% and the enrichment factor of 63.5 was achieved. The studied analyte was successfully extracted and determined with high efficiency using cloud point extraction method in water and biological matrices.