Progress is reported towards the development of a new route to obtain cadmium sulfide (CdS) thin films by using ethylene-diamine-tetra-acetic acid (EDTA) ligand on the chemical bath deposition (CBD) method. Different chemical baths are used to study changes in the structures of the CdS films for different EDTA concentrations. X-ray diffraction (XRD) is used to prove the structural characterization of the samples, and to obtain the grain size with the Scherrer's equation. The pH variations during the growth also affect the structural film quality, and it was verified by using ammonia chloride as an auxiliar-buffer plus Triton-X100.

A B S T R A C TEndocrine disrupting determination at low concentration levels comprises one of the most important targets in environmental analytical chemistry. In spite of inherent high sensitivities obtained for HPLC, these techniques have some limitations depending on the contaminants. As a result, interest in preconcentration using solid-phase extraction (SPE) still continues increasingly for endocrine disrupting determinations by HPLC due to the high accuracy of this method. In this work, we evaluated three different adsorbents in preconcentration of endocrine disruptors in three different categories: pharmaceuticals (sulphamethoxazole, trimethoprim and diclofenac), hormones (estrone, 17β-estradiolacetate and 17β-estradiol) and plastic materials (bisphenol A) in multicomponent aqueous solution using the combination SPE -HPLC. The adsorbents investigated were such as modified silica (octadecylsilane)-DSC-18 (Supelco) and two polymers, a divinylbenzene-N-vinilpirolidona -Oasis ® HLB (Waters) and a styrene-divinylbenzene modified with butyrolactone-Strata-X™ (Phenomenex). The parameters selected to evaluate the best adsorbent were sample loaded, breakthrough volume, recovery and adsorption capacity. The results showed that the polymeric sorbents Oasis and Strata presented good separation and selective ability, then the most efficient sorbent for the described test was applied to the determination of endocrine disruptor (ED) in a wastewater real sample. Almost all endocrine disruptors studied in the present work were found and quantified in the effluent sample, suggesting the selected cartridge could be useful for preconcentration technique of endocrine disruptors in environmental analytical applications. Correlation analysis identified the adsorption parameters which had the most influence in efficiency of SPE adsorbents, such as initial ED concentration, breakthrough volume and recovery.