A silica gel-bound macrocycle system for the selective separation of toxic cadmium from metal-affluent aqueous matrix

Abstract

Selective separation of cadmium(II) on a macrocycle immobilized solid phase extraction (SPE) system namely AnaLig Cd-01, and commonly known as molecular recognition technology (MRT) gel, have been examined. The MRT-SPE able to retain the cadmium from the metal-affluent aqueous matrix at the pH range of 2 to 8, and the captured species can be recovered via elution with 1 and 6 M HNO3. Besides the effects of solution pH and eluent concentration, the impacts of sample loading flow rates and coexisting matrix ions were also investigated and optimized. The Cd(II) retention capacity of the MRT-SPE was 0.26 mmol g-1, and it can be reused for more than 100 loading and elution cycles. The Cd(II) recovery attained from the metal-spiked natural waters was satisfactory (95.3–98.1%). However, the Cd(II) retention ability of the MRT-SPE was significantly decreased when excess of chelant remain in the aqueous waste matrix. Graphical abstract

Selective separation of elements from complex solution matrix with molecular recognition plus macrocycles attached to a solid-phase: A review

“…The application of silica gel-bound macrocycle systems for the selective separation of cadmium [145] from the metal-affluent matrix, or hexavalent chromium from the wastewaters [146] and conversion coatings [147] has been reported.…”

Selective Separation of Tri- and Pentavalent Arsenic in Aqueous Matrix with a Macrocycle-Immobilized Solid-Phase Extraction System

“…SPE techniques have been applied for the quantified analysis/speciation/separation of various trace elements, including arsenic (Liska 2000, Rossi & Zhang 2000, Yalcin & Le 2001, Camel 2003, Yu et al 2003, Sanchez et al 2009, Rahman et al 2011a, 2011b. One group of SPE material includes the macrocyclic chelants, such as crown ethers, immobilized on a silica or polymer support (Hiraoka 1982(Hiraoka , 1992, which possess the ion-selective behavior and are commonly known as molecular recognition technology (MRT) gel , Hasegawa et al 2010, Rahman et al 2011a, 2011b, 2011c, 2011d, Hasegawa et al 2013). …”