RESUMEN
In this paper, we have developed a simple colorimetric method for detection of resorcinol (RE); the method is based on the reaction of RE with silver ions (oxidizing agent) in the presence of starch as a stabilizer and formation of silver nanoparticles (AgNPs). At nanometer dimensions the electron cloud can oscillate on the particle surfaces when dispersed in liquid media so these nanoparticles exhibit a strong UV-Vis extinction band. A UV-Vis spectrophotometer is used to monitor the changes of the localized surface plasmon resonance (LSPR) of AgNPs at a wavelength of 430 nm. There is a linear relationship between absorbance intensity of AgNPs and the concentration of RE over the range of 4 × 10(-6) to 1.1 × 10(-5) mol L(-1) at 430 nm. The detection limit was 1.2 × 10(-6) mol L(-1). The proposed method has been successfully applied for the determination of RE in anti-acne solution and spiked shampoo samples.
RESUMEN
The adsorption and removal of amaranth (AM) from an aqueous solution by iron oxide nanoparticles (IONPs) coated with cetyltrimethylammonium bromide (CTAB) as adsorbent was reported. The novel magnetic separation was quite efficient for the adsorption and desorption of AM. In an aqueous solution of AM at 25 degrees C, the adsorption data could be fitted by the Langmuir equation with a maximum adsorption amount of 1.05 mg mg(-1) and a Langmuir adsorption equilibrium constant of 0.90 Lmg(-1). The effect of temperature, pH of aqueous medium, electrolyte concentration, composition of desorbent solvent and interfering ions on the recovery process were also investigated. Methanol was used for desorption of adsorbed AM. Due to the absence of internal diffusion resistance both adsorption and desorption of AM were fast and could be completed within 5 min. The results indicated that the CTAB-coated IONPs could be employed in the removal of the anionic dye from wastewater. The AM was removed successfully in spiked samples of Karoon River water.
Asunto(s)
Colorante de Amaranto/aislamiento & purificación , Colorantes/aislamiento & purificación , Compuestos Férricos/química , Nanopartículas del Metal/química , Purificación del Agua/métodos , Adsorción , Colorante de Amaranto/química , Cetrimonio , Compuestos de Cetrimonio/química , Colorantes/química , Magnetismo , Metanol/química , RíosRESUMEN
This study presents a novel separation, preconcentration and determination of basic fuchsin (BF) in an aqueous solution by sodium dodecyl sulfate (SDS)-bounded iron oxide nanoparticles (S-IONPs). It is shown that the novel magnetic nano-adsorbent is quite efficient for the adsorption and desorption of BF at 25 degrees C. Different parameters such as pH, temperature, ionic strength and composition of desorbent solvent were optimized. The effect of some co-existing ions on the determination was investigated. The nanoparticles were analyzed by transmission electron microscopy (TEM) and the sizes of S-IONPs were in the range of 20-100 nm. The method showed good linearity for the determination of BF in the range of 10-300 ng mL(-1) with a regression coefficient of 0.9989. The limit of detection (LOD) (signal-to-noise ratio of 3:1) was 0.0073 microg L(-1) and the relative standard deviation (RSD) for 0.03 microg mL(-1) and 0.2 microg mL(-1) of BF were 4.53% and 4.73%, respectively. The BF was determined successfully in spiked samples of Karoon River water.