Silica Xerogel Doped with Iron(III) as Sensor Material for Salicylhydroxamic Acid Determination in Urine

Salicylhydroxamic acid (SHA) is used as antimicrobic medicine and its concentration has to be monitored in urine. For the first time, silica xerogels doped with iron(III) have been proposed as sensor materials for SHA determination in biological samples. Three xerogels with iron(III) content in the range of 0.04–1.74% wt have been synthesized. BET surface area of these xerogels has varied in the range of 696–529 m2/g and total pore volume has varied in the range of 0.92–0.23 cm3/g. Complex formation between immobilized iron(III) and salicylhydroxamic acid has been investigated with solid phase spectrophotometry and IR spectroscopy. Orange-brown iron(III)-SHA complex with 1:1 stoichiometry is formed at pH 1–4 with half-reaction time of 17 min. Silica xerogel doped with 0.33% wt iron(III)) has been used as sensor material for SHA solid phase spectrophotometric determination (LOD 1.4 mg/L (n = 3), analytical range 4–230 mg/L). Proposed sensor material has been applied for SHA determination in biological samples of synthetic and human urine. The proposed procedure is characterized by a good level of accuracy (recovery values 97–120%) and precision (RSD values 4–9%) and can be recommended for pharmacokinetic–pharmacodynamic studies of hydroxamic acid-based medications.

The Analysis of Low-Cost Pb(II) Adsorbents using Batch Method of Solid-Phase Spectrophotometry

Heavy metal pollutants contained in wastewater can cause health problems for living things around. Minor to fatal health problems can occur due to heavy metal poisoning, mainly caused by Pb(II) metal.. This study aimed to determine the optimum mass combination of rice husk and zeolite to adsorb Pb(II) metal ions in simulated wastewater, and to determine the sensitivity of the analysis method. This study used Solid Phase Spectrophotometry (SPS) to determine the decrease in Pb(II) metal ion levels after being adsorbed by activated carbon from rice husks and zeolites. This study used an experimental method with simulated wastewater samples containing Pb(II) at several concentrations. Pb(II) adsorption processes by rice husk and natural zeolite used various adsorbents' mass ratios. The adsorbents were characterized by using Fourier-Transform Infra-Red (FTIR) Spectrophotometry. Pb(II) analysis during adsorption processes used a single beam UV-visible Spectrophotometer for Solid-Phase Spectrophotometry. This study indicates that the combination of adsorbent from rice husk and natural zeolite can properly adsorb Pb(II) ions with an adsorption capacity of 0.75 μg g-1 and 0.025 μg L-1 for the LoD of the instrument.

The Analysis of Low-Cost Pb(II) Adsorbents using Batch Method of Solid-Phase Spectrophotometry

Heavy metal pollutants contained in wastewater can cause health problems for living things around. Minor to fatal health problems can occur due to heavy metal poisoning, mainly caused by Pb(II) metal.. This study aimed to determine the optimum mass combination of rice husk and zeolite to adsorb Pb(II) metal ions in simulated wastewater, and to determine the sensitivity of the analysis method. This study used Solid Phase Spectrophotometry (SPS) to determine the decrease in Pb(II) metal ion levels after being adsorbed by activated carbon from rice husks and zeolites. This study used an experimental method with simulated wastewater samples containing Pb(II) at several concentrations. Pb(II) adsorption processes by rice husk and natural zeolite used various adsorbents' mass ratios. The adsorbents were characterized by using Fourier-Transform Infra-Red (FTIR) Spectrophotometry. Pb(II) analysis during adsorption processes used a single beam UV-visible Spectrophotometer for Solid-Phase Spectrophotometry. This study indicates that the combination of adsorbent from rice husk and natural zeolite can properly adsorb Pb(II) ions with an adsorption capacity of 0.75 μg g-1 and 0.025 μg L-1 for the LoD of the instrument.