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Removal of Pb(II) ions from aqueous solution using complexation-ultrafiltration

Şahin D., Tascıoglu S.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 2

80--84

EN

Ligand-modified micellar-enhanced ultrafi ltration (LM-MEUF) is a membrane technique based on a separation process which can be used for removal of target metals from an aqueous solution. This method involves adding both a metal complexing ligand and surfactant molecule to the aqueous solution under conditions where most of the molecules are present as micelles. This ligand can be attached to the surface of micelles by solubilization and forms the ligand complexes with the metal ion. The aqueous solution is then treated through a membrane which has to be smaller pore sizes than those of the complexes. Hence, permeate water is then purified from the heavy metals. In this study, divalent lead is the target ion in a solution. Filtration experiments were performed with ultrafi ltration membrane system, equipped with a regenerated cellulose membrane with a 5000 Daltons cutoff. The pressure was fixed at 4.0 bar with a permeate flow rate of 500 mL min–1 . Complexes of Pb2+ ions with three ligands were investigated in micellar medium of different surfactants at different pH values to determine the ligands which could provide separation. Different parameters affecting the percentage rejection of the Pb2+ , such as pH and surfactant concentration were also discussed. Results have shown that the maximum percentage of the Pb2+ ions rejection were obtained using sodium dodecyl sulfate (SDS) as a surfactant and dithizone (DZ) as the lead-specifi c ligand. A waste stream sample from a battery plant was subjected to LM-MEUF process in the optimum conditions determined in this study and it was shown that Pb2+ ions in a waste stream could be removed by LM-MEUF effectively.

2

Simultaneous determination of thimerosal and aluminum in vaccines and pharmaceuticals with the use of HPLC method

Zaręba M., Sanecki P. T., Rawski R.

Acta Chromatographica

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2016

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Vol. 28, no. 3

299--311

EN

A simple and convenient chromatographic method of simultaneous separation, identification, and quantitative determination of thimerosal (TM) (preservative) and aluminum (adjuvant) in vaccines and pharmaceuticals by reversed phase highperformance liquid chromatography (RP-HPLC) with visible (VIS) detection was developed and validated. Due to postcolumn derivatization with dithizone, any interference from matrix was excluded. Similarly, a possibility of on-column decomposition of dithizonates was eliminated. Evaluated detection limits were 0.3 μg TM and 3.0 μg Al, which correspond to the smallest, but possible to recognize, visible peak.

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A new Zn2+-selective potentiometric sensor based on dithizone - PVC membrane

Gupta V. K., Jain A. K., Maheshwari G.

Chemia Analityczna

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2006

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Vol. 51, No. 6

889-897

EN

Zn2+ selective sensor has been fabricated using poly(vinyl chloride) (PVC) matrix membranes containing a neutral carrier dilhizone (I) as an ionophore. The sensor exhibited the best performance for the following membrane composition: (I): PVC-sodium tetraphenyl borate-1 -chloronapthalene (5:150:2:150). This membrane worked well over a wide concentration range of Zn2+, i. e. 5.1 x 10-6 x 1.0 x 10-1 mol L-1and the corresponding calibration plots exhibited a Nernstian slope of 29.7 š 0.1 m V per decade of Zn2+ activity. The response time of the sensor was shorter Than 8 s and the membrane could be used over a period of 6 months with good reproducibilily. The proposed sensor could be operated over a wide pH range (3.1-6.5) and demonstrated good selectivity towards the analyte in the presence of several mono-, di- and trivalenl cations. It could be also used in partially non-aqueous media containing up to 20% (v/v) of methanol. ethanol, or acetone and its Nerstian slope in the working concentration range remained almost unchanged. The proposed sensor has been used for determination of Zn2+ in human hair samples by direct potentiometry.

PL

Sensor Zn2+selektywny przygotowano używając membran na bazie matrycy z polichlorku winylu) (PCW) zawierającej obojętny nośnik - ditizon (1) jako jonofor. Najlepsze właściwości wykazywała membrana o składzie (I): PCW: tetrafenyloboran sodu: l-chloronaftalen w stosunku 5:150:2:150. Membrana ta pracowała poprawnie w zakresie stężeń Zn2+ szerszym niż 5.1 x 10-6-1.0 x 10-1 mo! Lsup>-1 z Nernstowskim nachyleniem 29-7 š 0-1 mV/dekada. Czas odpowiedzi sensora jest mniejszy niż 8 s i membrana może pracować przez okres dłuższy niż 6 miesięcy z dobrą odtwarzalnością. Zaproponowany sensor działa poprawnie w szerokim zakresie pH (3.1-6.5) i wykazuje dobrą dyskryminację wobec wielu jedno-, dwu- i trójwartościowych kationów. Sensor może być stosowany w częściowo nie-