Ultrasound assisted emulsification microextraction for selective determination of trace amount of mercury(II)

An environmental friendly sample pre-treatment method, ultrasound assisted emulsification microextraction, followed by furnace atomic absorption spectrometry is reported for the selective determination of mercury(II). Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, volume of chelating agent, sample pH, extraction time, temperature and addition of salt, are optimized. Under the optimum conditions for extraction recovery, 80 µL of tetrachloroethylene as extraction solvent and 1000 µL of [4-benzylidenamino- 3,4 dihydro-6-methyl 3-thioxo-1,2,4-triazin-5(2H)-one] as complexing agent give the best results. Under the optimum conditions, the calibration curve is linear in the range of 100-800 µg L-1, relative standard deviation is 2.8% for five analysis of sample solution containing 0.3 mg L−1 Hg(II) with the limit of detection of 0.043 mg L-1. The method has been applied successfully for assessing matrix effect by analysis of non- piked and spiked real samples. The results demonstrate a successful robustness of the method for quantitative and selective determination of trace amount of mercury(II) in water and wastewater samples with relative recovery of 96-103%

Ultrasound assisted emulsification microextraction for selective determination of trace amount of mercury(II)

423-428<span style="font-size:11.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">An environmental friendly sample pre-treatment method, ultrasound assisted emulsification microextraction, followed by furnace atomic absorption spectrometry is reported for the selective determination of mercury(II). Parameters that affect the extraction efficiency, such as the kind and volume of the extraction solvent, volume of chelating agent, sample pH, extraction time, temperature and addition of salt, are optimized. Under the optimum conditions for extraction recovery, 80 µL of tetrachloroethylene as extraction solvent and 1000 µL of [4-benzylidenamino- 3,4 dihydro-6-methyl 3-thioxo-1,2,4-triazin-5(2H)-one] as complexing agent give the best results. Under the optimum conditions, the calibration curve is linear in the range of 100-800 µg L-1, relative standard deviation is 2.8% for five analysis of sample solution containing 0.3 mg L−1 Hg(II) with the limit of detection of 0.043 mg L-1. <span style="font-size: 11.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-bidi-font-family:mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;="" mso-bidi-language:hi"="" lang="EN-GB">The method has been applied successfully for assessing matrix effect by analysis of non-spiked and spiked real samples. The results demonstrate a successful robustness of the method for quantitative and selective determination of trace amount of mercury(II) in water and wastewater samples with relative recovery of 96-103%.</span

Fast chromium determination in pharmaceutical tablets by using electrochemical sensors: Preparation and comparison

In the present paper, three electrodes were prepared with the aim of detecting chromium (III) in pharmaceutical tablets and comparing their capabilities and efficiency. At first, N-(pyridine-2-ylcarbamothioyl) benzamide (NP2YCTB) was synthesized and characterized by 1H NMR, FTIR, and 13C NMR spectroscopy methods. Then, it is used as a sensing material to prepare three types of chromium potentiometry sensors including solid-state electrodes (SSE), coated wire electrodes (CWE) as asymmetric electrodes, and liquid membrane electrodes (LME) as symmetric electrodes. The responses of all electrodes were Nernstian. Field-emission scanning electron microscopy was utilized to investigate the liquid membrane morphology. The presence of chromium (III) in the membrane was proved using Energy-dispersive X-ray spectroscopy and the coordination of NP2YCTB heteroatoms with chromium (III) was confirmed by Fourier transform infrared spectroscopy. The limit of detection for SSE (3 × 10−9 mol/L) was enhanced compared with LME (7 × 10−6 mol/L) and CWE (3 × 10−7 mol/L). The response time of electrodes was very short so it was about 5–6 s for LME and CWE and 5–8 s for SSE. The sensors were used for the potentiometric determination of chromium (III) in pharmaceutical tablets and in the potentiometric titration of it with EDTA

Hydrogen bond-mediated self-assembly of Tin (II) oxide wrapped with Chitosan/[BzPy]Cl network: An effective bionanocomposite for textile wastewater remediation

A novel and efficient bionanocomposite was synthesized by incorporating SnO into chitosan (Ch) and a room-temperature ionic liquid (RTIL). The bionanocomposite was synthesized in benzoyl pyridinium chloride [BzPy]Cl to maintain the unique properties of SnO, chitosan, and the ionic liquid. Adsorption and photodegradation processes were applied to evaluate the bionanocomposite for removing azo and anthraquinone dyes and textile wastewater. SnO/[BzPy]Cl and SnO/[BzPy]Cl/Ch samples were prepared and characterized using various techniques, including FT-IR, SEM, XRD, EDAX, XPS, DSC, TGA, nitrogen adsorption/desorption isotherm, and DRS analysis. SEM analysis revealed a hierarchical roughened rose flower-like morphology for the biocomposite. The band gap energies of SnO/[BzPy]Cl and SnO/[BzPy]Cl/chitosan were found to be 3.9 and 3.3 eV, respectively, indicating a reduction in the band gap energy with the introduction of [BzPy]Cl and chitosan. SnO/[BzPy]Cl/Ch showed high removal rates (92–95 %) for Fast Red, Blue 15, Red 120, Blue 94, Yellow 160, and Acid Orange 7 dyes. The adsorption kinetics followed a pseudo-second-order model.In addition, the effect of different photodegradation parameters such as solution pH, dye concentrations, contact time, and amount of photocatalyst, was studied. Given the optimal results obtained in removing azo and anthraquinone dyes, the SnO/[BzPy]Cl/Ch nanocomposite was used as an efficient nanocomposite for removing dyes from textile wastewater. The highest removal efficiency was found to be 95.8 %, obtained under ultraviolet and visible light. Furthermore, BOD and COD reduction analysis showed significant reductions, indicating the excellent performance of the photocatalyst