A simple and sensitive solid phase extraction utilizing C18 filled cartridges incorporated with dithizone for preconcentration of lead and its subsequent determination by flame atomic absorption spectrometry (FAAS) wa...A simple and sensitive solid phase extraction utilizing C18 filled cartridges incorporated with dithizone for preconcentration of lead and its subsequent determination by flame atomic absorption spectrometry (FAAS) was developed. Several parameters such as type, concentration and volume of eluent, pH of the sample solution, flow rate of extraction and volume of the sample were evaluated. The effect of a variety of ions on preconcentration and recovery was also investigated. At pH = 7.4 and 1.0 mol?L–1 HCl eluting them, lead ions were recovered quantitatively. The limit of detection (LOD) defined as 3Sbl was determined to be 8.1 μg L–1 for 500 mL of sample solution and eluted with 5 mL of 1.0 mol?L–1 HCl under optimum conditions. The accuracy and precision (RSD %) of the method were >90% and <10%, respectively. In the end, the proposed method was applied to a number of real sugar samples and the amount of lead was determined by spiking a known concentration of lead into the solution.展开更多
The adsorption behavior of the organobentonite (CTMAB-bentonite) modified with dithizone for lead ion in water was investigated.A sort of cheap sorbent was prepared through modifying organobentonite with dithizone and...The adsorption behavior of the organobentonite (CTMAB-bentonite) modified with dithizone for lead ion in water was investigated.A sort of cheap sorbent was prepared through modifying organobentonite with dithizone and was characterized with FT-IR.By means of flame atomic absorption spectrometry (FAAS), the adsorption situation and mechanism were studied.The results showed that after treating bentonite with cetyl trimethyl ammonium bromide (CTMAB),dithizone could be immobilized on the bentonite firmly.The lead ion in water could be adsorbed quantitatively on the organobentonite modified with dithizone, and the adsorbed quantity was affected by pH value of medium, temperature and time.The adsorption behavior followed a Langmuir adsorption isotherm and a pseudo-second-order kinetic model.The enthalpy change of the adsorption process was 58.432 kJ·mol-1,and Gibbs free energy change was negative at different temperatures.The reaction of adsorption was an spontaneous, endothermal process.展开更多
文摘A simple and sensitive solid phase extraction utilizing C18 filled cartridges incorporated with dithizone for preconcentration of lead and its subsequent determination by flame atomic absorption spectrometry (FAAS) was developed. Several parameters such as type, concentration and volume of eluent, pH of the sample solution, flow rate of extraction and volume of the sample were evaluated. The effect of a variety of ions on preconcentration and recovery was also investigated. At pH = 7.4 and 1.0 mol?L–1 HCl eluting them, lead ions were recovered quantitatively. The limit of detection (LOD) defined as 3Sbl was determined to be 8.1 μg L–1 for 500 mL of sample solution and eluted with 5 mL of 1.0 mol?L–1 HCl under optimum conditions. The accuracy and precision (RSD %) of the method were >90% and <10%, respectively. In the end, the proposed method was applied to a number of real sugar samples and the amount of lead was determined by spiking a known concentration of lead into the solution.
文摘The adsorption behavior of the organobentonite (CTMAB-bentonite) modified with dithizone for lead ion in water was investigated.A sort of cheap sorbent was prepared through modifying organobentonite with dithizone and was characterized with FT-IR.By means of flame atomic absorption spectrometry (FAAS), the adsorption situation and mechanism were studied.The results showed that after treating bentonite with cetyl trimethyl ammonium bromide (CTMAB),dithizone could be immobilized on the bentonite firmly.The lead ion in water could be adsorbed quantitatively on the organobentonite modified with dithizone, and the adsorbed quantity was affected by pH value of medium, temperature and time.The adsorption behavior followed a Langmuir adsorption isotherm and a pseudo-second-order kinetic model.The enthalpy change of the adsorption process was 58.432 kJ·mol-1,and Gibbs free energy change was negative at different temperatures.The reaction of adsorption was an spontaneous, endothermal process.
