On-line preconcentration and determination of copper, lead and chromium(VI) using unloaded polyurethane foam packed column by flame atomic absorption spectrometry in natural waters and biological samples

A Sensitive Method for Cadmium Determination Using an On-line Polyurethane Foam Preconcentration System and Thermospray Flame Furnace Atomic Absorption Spectrometry

“…Both LOD and LOQ were calculated as the ratios of three and ten times the standard deviations of the blank (n = 20) to the slopes of the calibration curves, and were found to be 0. 12 important to note that when only TS-FF-AAS was used, the LOD and LOQ achieved were, respectively, 0.62 and 2.12 µg l -1 , which are higher than those obtained by the FI-TS-FF-AAS system. From these values it is possible to note an increase in the sensitivity after coupling the flow system to TS-FF-AAS.…”

“…Its advantages include low sample/reagent consumption, high enrichment factors and high sample throughput. Synthetic adsorbents, such as modified silica (C18), 9 fullerene (C60), 10 Amberlite-XAD-2 resins 11 and polyurethane foams (PUF) 12 12,13 In the first case, considering that PUF presents fairly hydrophobic behavior, only neutral complexes, negatively charged complexes or high polarizability molecules can be adsorbed onto its surface. 14 Chelating agents containing dithiophosphate groups, such as ammonium Ο,Ο-diethyldithiophosphate (DDTP) show stability in an acid medium and react with several transition metals and semimetals, but do not react with alkali and alkali earth metals.…”

Polyurethane composite adsorbent using solid phase extraction method for preconcentration of metal ion from aqueous solution

“…Numerous preconcentration and separation techniques application have been reported for metal-ion analysis, which include cloud-point extraction (CPE) (Anthemidis et al 2001(Anthemidis et al , 2002, co-precipitation (Duran et al 2009), electrochemical deposition (ECD) (Soylak and Tuzen 2008), flotation (Pan et al 2007), liquid-liquid extraction (LLE) (Candir et al 2008), solid-phase extraction (SPE) (Otero-Romani et al 2005;Elci et al 2008;Huang et al 2008;Chen et al 2009), solid-phase microextraction (SPME) (Camel 2003;Chen et al 2009), etc. However, SPE is the preferred method mainly due to its simplicity, direct application in microlitre (lL) volume, speed, minimal sample loss, higher preconcentration factor, rapid phase separation, cost and time saving (Bulut and Tez 2007;Chen et al 2009;Mohammadi et al 2011).…”

“…phase, to the active sites on the solid phase of an adsorbent (Bulut and Tez 2007). Numerous technologies involving adsorbents have been applied as preconcentration adsorbents for metal ions, including alumina (Li et al 2002;Absalan and Mehrdjardi 2003), activated carbon (AC) (Ensafi et al 2003;Gupta et al 2012a, b;Olorundare et al 2012), C18 cartridge silica, chelex-100 (Ferri and Sangiorgio 1996), polyurethane foam (Anthemidis et al 2002;Pinto et al 2004), microcrystalline naphthalene (Candir et al 2008;Elci et al 2008), nanoparticles (Gupta and Nayak 2012;Sanghavi et al 2013), silica gel (Akl et al 2004), cyclodextrins CDs (Krause et al 2010), zeolites (Ngah et al 2012), and clay (Kiliaris and Papaspyrides 2010). However, the development of purification and extraction methods using these adsorbents for the enrichment of metal ions in environmental samples has been a challenge due to drawbacks which have limited their application for effective monitoring and curtailments of pollutants in the environment (Pinto et al 2004;Alkan et al 2008;Castro et al 2011).…”

Octa-<i>O</i>-Methoxy Resorcin [4] Arene Amberlite XAD-4 Polymeric Chelating Resin for Solid Phase Extraction, Preconcentration, Separation and Trace Determination of Ni(II), Cu(II), Zn(II) and Cd(II) Ions

“…Various SPE materials which have been used for the preconcentration of trace metal ions as their chelates include, activated silica gel [40,41], carbon [42][43][44][45], polyurethane foam [46] microcrystalline naphthalene [47], C 18 cartridges [48], Chelex-100 [49], Alumina [50], functionalized polyurethane foam [51], modified silica [52,53], sulfur powder [54] and Amberlite XAD resins [55][56][57][58][59][60][61]. Amberlite XAD (styrene-divinyl benzene copolymer) resins, as the copolymer backbone for the immobilization of chelating ligands, have some physical superiority, such as porosity, uniform pore size distribution, high surface area, and chemical stability toward acids, bases, and oxidizing agents, as compared to other resins [62][63][64][65].…”