A novel thiocarbohydrazide derivative for preconcentration of copper(II), nickel(II), lead(II), and cadmium(II) in water samples for flame atomic absorption spectrophotometry (FAAS)

Abstract

a b s t r a c tA preconcentration procedure has been developed by using a thiocarbohydrazide derivative (1,5-bis(phenylthiocarbamoyl)thiocarbohydrazide) as a novel sorbent. The ligand was synthesized and used for preconcentration of Cu(II), Ni(II), Pb(II), and Cd(II) ions from water samples by batch and column procedures to enrich metal concentrations appropriate for flame atomic absorption spectrophotometry (FAAS). The optimum pHs for effective solid-phase extractions were 5 and 7 for Cu(II), and Ni(II), Pb(II) and Cd(II) adsorptions, respectively. The method detection limits 0.73, 0.05, 1.14 and 0.04 ng mL -1 ; the method determination limits 2.4, 0.15, 3.76 and 0.13 ng mL -1 and the enrichment factors 30, 65, 26 and 50 were found for Cu(II), Ni(II), Pb(II) and Cd(II), respectively. The sorption and desorption yields and overall recoveries of metals were almost quantitative except Pb(II) of which sorption yield was around 72% with relative standard deviation value around 1.8%. Langmuir, Freundlich and Temkin models were examined for the metal adsorptions. The Langmuir isotherm model provided a better fit with high correlation coefficients. Regarding the Langmuir parameters, the maximal adsorption capacities on 1,5-bis(phenylthiocarbamoyl)thiocarbohydrazide were 18.25, 7.99, 13.26 and 12.96 mg g -1 for Cu(II), Ni(II), Pb(II) and Cd(II), respectively. The adsorption kinetics for the adsorptions of metals were studied by using linear forms of pseudo-first-order and pseudo-second-order kinetic models. Pseudo-second-order kinetic model fitted very well. The developed method has been successfully applied to the preconcentration of Cu(II), Ni(II), Pb(II) and Cd(II) in water samples (tap water, seawater and mineral water samples), and satisfactory and reproducible results were obtained in FAAS analysis.

Nano-Clay and Iron Impregnated Clay Nanocomposite for Cu2+ and Pb2+ Ions Removal from Aqueous Solutions

“…Figure 9 indicates the effect of pH on copper (II) and lead (II) removal efficiencies of the nano-clay and iron impregnated nanoclay. Copper (II) and lead (II) ions have the highest tendency to form a precipitate at alkaline conditions and be separated from an aqueous solution by a mechanism of chemical precipitation (Çetinkaya & Aydin, 2017; Pang et al, 2009). Pang et al (2009) reported an effective pH range of 7.8 to 8.8 and 6.3 to 11.1 for the highest lead hydroxide and copper hydroxide precipitations, respectively.…”

“…Pang et al (2009) reported an effective pH range of 7.8 to 8.8 and 6.3 to 11.1 for the highest lead hydroxide and copper hydroxide precipitations, respectively. Also, an optimum pH of 5.0 to 7.0 was reported for Pb 2+ and Cu 2+ adsorption (Çetinkaya & Aydin, 2017). In this study, the experiment was conducted at lower pH (pH 3.0 and 5.0) to exclude the higher pH induced metal hydroxide precipitation (Pb(OH) 2 $ & Cu(OH) 2 $) and clearly understand the adsorbents activity without any intervention.…”

A facile and sensitive coprecipitation method coupled with flame atomic absorption spectrometry for quantification of Cu(II) ions in complex matrices

“…One of these problems is the interference effect of the complicated matrix and the other is that the lower levels of trace element than the detection limit of the utilized instrument. 13 In order to eliminate these drawbacks, it is indispensable to implement a traditional separation and preconcentration method such as solid phase extraction, 14 cloud point extraction, 15 liquid-liquid extraction 16 and coprecipitation 8 before the analyses step. Among these, coprecipitation is a powerful alternative due to its low cost, simplicity and rapidity, less usage of chemical reagents and obtaining high preconcentration factors in the method.…”