Use of nanomaterials in the pretreatment of water samples for environmental analysis

The challenge of providing clean drinking water is of enormous relevance in today’s human civilization, being essential for human consumption, but also for agriculture, livestock and several industrial applications. In addition to remediation strategies, the accurate monitoring of pollutants in water sup-plies, which most of the times are present at low concentrations, is a critical challenge. The usual low concentration of target analytes, the presence of in-terferents and the incompatibility of the sample matrix with instrumental techniques and detectors are the main reasons that renders sample preparation a relevant part of environmental monitoring strategies. The discovery and ap-plication of new nanomaterials allowed improvements on the pretreatment of water samples, with benefits in terms of speed, reliability and sensitivity in analysis. In this chapter, the use of nanomaterials in solid-phase extraction (SPE) protocols for water samples pretreatment for environmental monitoring is addressed. The most used nanomaterials, including metallic nanoparticles, metal organic frameworks, molecularly imprinted polymers, carbon-based nanomaterials, silica-based nanoparticles and nanocomposites are described, and their applications and advantages overviewed. Main gaps are identified and new directions on the field are suggested.publishe

Separation/preconcentration of Zn(II), Cu(II), and Cd(II) by Saccharomyces carlsbergensis immobilized on silica gel 60 in various samples

WOS: 000241680900010This study presents a solid phase extraction procedure based on column biosorption of Zn(II), Cu(II), and Cd(II) ions on Saccharomyces carlsbergensis immobilized on silica gel 60. The analytes were determined by flame atomic absorption spectrometry (FAAS). The optimum conditions for the quantitative recovery of the analytes, including pH, amount of solid-phase, eluent type and flow rate of sample solution were examined. The effect of interfering ions on the recovery of the analytes was also investigated. Under the optimum conditions, recoveries of Zn(II), Cu(II), and Cd(II) were 99 +/- 2%, 98 +/- 2%, and 100 +/- 2% at 95% confidence level, respectively for spiked water samples. The analytical detection limits for Zn(II), Cu(II), and Cd(II) were 1.14, 1.66, and 1.48 ng mL(-1), respectively. The validation of the method was checked by the analysis of standard reference material (Tea leaves GBW-07605) and spiked water, samples. The proposed method was applied for the determination of analytes in green onion, parsley, dam water, lake water, and tap water samples. The analytes has been determined in real samples with relative error lower than 8% and relative standard deviation lower than 10%

Application of factorial design in optimization of nickel preconcentration by solid phase extraction and its determination in water and food samples by flame atomic absorption spectrometry

WOS: 000260089700004A procedure for the preconcentration and determination of trace nickel in water and food samples using flame atomic absorption spectrometry (FAAS) is presented. It is based on column solid-phase extraction of nickel(II) ion by using Amberlyst 36 resin as a solid phase. The optimization step was carried out by using 2(3) full factorial design for the variables such as pH, flow rate and concentration of the analyte. In the established experimental conditions, nickel can be determined with a relative standard deviation of 1.8% for a nickel concentration of 100 mu g/L. Analytical detection limit was 0.86 mu g/L (N=20). The adsorption capacity of Amberlyst 36 is found to be 143 mg/g for nickel. The accuracy was confirmed by analysis of certified reference materials (tea leaves GBW 07605 and clay loam CMI 7003). The method was applied for nickel determination in real samples of tap water, waste water, dam water, carrot, parsley and lettuce.Gazi UniversityGazi University [05/2006-34]The authors are grateful for the financial support of the Scientific Research Projects of Gazi University (The project number is (05/2006-34)