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On-line micro column preconcentration system based on amino bimodal mesoporous silica nanoparticles as a novel adsorbent for removal and speciation of chromium (III, VI) in environmental samples.

Shirkhanloo H, Khaligh A, Golbabaei F, Sadeghi Z, Vahid A, Rashidi A - J Environ Health Sci Eng (2015)

Bottom Line: TEM, XRD, and SEM results confirmed the beneficial properties of NH2-UVM-7 as the adsorbent for chromium extraction.The efficiency of nanoadsorbent for preconcentration and extraction of Cr (VI) was 96 %, whereas it was less than 5 % for Cr (III).Good recoveries, with low detection limits and good preconcentration factors are the main advantages of this procedure.

View Article: PubMed Central - PubMed

Affiliation: Occupational and Environmental Health Research Center (OEHRC), Iranian Petroleum Industry Health Research Institute (IPIHRI-PIHO), Tehran, 1485733111 Iran ; Research Institute of Petroleum Industry (RIPI), Tehran, 14665-1137 Iran.

ABSTRACT

Background: Chromium (VI) has toxic and carcinogenic effects. So, determination and speciation of chromium in environmental samples is very important in view of health hazards. In this study, solid phase extraction (SPE) based on bulky amine-functionalized bimodal mesoporous silica nanoparticles (NH2-UVM-7) as a novel nanoadsorbent was applied for preconcentration and speciation of chromium (III, VI) in water samples.

Methods: UVM-7 was synthesized via atrane route and subsequently functionalized with amino silane via grafting method. In SPE procedure, polymer tubing as a micro-column was filled with NH2-UVM-7 adsorbent. Preconcentration and speciation of Cr (III) and Cr (VI) ions with NH2-UVM-7 were obtained in water samples due to the fact that only Cr (VI) ions can be complexed with-NH2 groups at optimized pH. Finally, chromium concentration was determined by flame atomic absorption spectrometry (F-AAS).

Results: TEM, XRD, and SEM results confirmed the beneficial properties of NH2-UVM-7 as the adsorbent for chromium extraction. Under the optimal conditions, linear calibration curve, detection limit and preconcentration factor were obtained 6-320 μg/ L, 1.2 μg/L and 66.7, respectively (RSD < 5 %). The efficiency of nanoadsorbent for preconcentration and extraction of Cr (VI) was 96 %, whereas it was less than 5 % for Cr (III).

Conclusions: The developed NH2-UVM7-based SPE/F-AAS method has enough sensitively and simplicity for speciation and determination of Cr (VI) and Cr (III) ions in real water samples. Good recoveries, with low detection limits and good preconcentration factors are the main advantages of this procedure.

No MeSH data available.


Related in: MedlinePlus

Nitrogen physisorption isotherms of NH2-UVM-7 and UVM-7
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Fig2: Nitrogen physisorption isotherms of NH2-UVM-7 and UVM-7

Mentions: The nitrogen adsorption-desorption isotherms of UVM-7 and NH2-UVM-7 were determined and displayed in Fig. 2. The corresponding isotherm of both samples displays two distinct regions at medium and at high relative pressure which can be attributed to the presence of bimodal pore system. The first is related to the presence of small mesopores (IUPAC clacification), and the second is related to the large mesopores, respectively. The observation of these two distinct regions in both the samples, UVM-7 and NH2-UVM-7, confirms that the UVM-7 bimodal pore system is remained almost intact after the functionalization with triethoxysililpropylamine. Textural properties of UVM-7 and NH2-UVM-7 were determined and presented in Table 3. The specific surface area (SBET) of UVM-7 and NH2-UVM-7 calculated from the linear part of the BET equation were 863 m2/g and 626 m2/g, respectively. Decreasing of BET surface area, pore volume, and pore diameter of NH2-UVM-7 in comparison with initial UVM-7 is due to the grafting of aminosilane on silica walls. The unit cell parameter (a0) and the average pore wall thickness (Wt) of the sorbents were calculated by the equations of a0 = 2.d100/√3 and Wt = a0– (dp/1.05), respectively, where dp is the pore diameter of adsorbent and d100 is obtained from XRD diffractograms. As shown in Table 3, these two parameters are almost constant for both the sorbents.Fig. 2


On-line micro column preconcentration system based on amino bimodal mesoporous silica nanoparticles as a novel adsorbent for removal and speciation of chromium (III, VI) in environmental samples.

Shirkhanloo H, Khaligh A, Golbabaei F, Sadeghi Z, Vahid A, Rashidi A - J Environ Health Sci Eng (2015)

Nitrogen physisorption isotherms of NH2-UVM-7 and UVM-7
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4940767&req=5

Fig2: Nitrogen physisorption isotherms of NH2-UVM-7 and UVM-7
Mentions: The nitrogen adsorption-desorption isotherms of UVM-7 and NH2-UVM-7 were determined and displayed in Fig. 2. The corresponding isotherm of both samples displays two distinct regions at medium and at high relative pressure which can be attributed to the presence of bimodal pore system. The first is related to the presence of small mesopores (IUPAC clacification), and the second is related to the large mesopores, respectively. The observation of these two distinct regions in both the samples, UVM-7 and NH2-UVM-7, confirms that the UVM-7 bimodal pore system is remained almost intact after the functionalization with triethoxysililpropylamine. Textural properties of UVM-7 and NH2-UVM-7 were determined and presented in Table 3. The specific surface area (SBET) of UVM-7 and NH2-UVM-7 calculated from the linear part of the BET equation were 863 m2/g and 626 m2/g, respectively. Decreasing of BET surface area, pore volume, and pore diameter of NH2-UVM-7 in comparison with initial UVM-7 is due to the grafting of aminosilane on silica walls. The unit cell parameter (a0) and the average pore wall thickness (Wt) of the sorbents were calculated by the equations of a0 = 2.d100/√3 and Wt = a0– (dp/1.05), respectively, where dp is the pore diameter of adsorbent and d100 is obtained from XRD diffractograms. As shown in Table 3, these two parameters are almost constant for both the sorbents.Fig. 2

Bottom Line: TEM, XRD, and SEM results confirmed the beneficial properties of NH2-UVM-7 as the adsorbent for chromium extraction.The efficiency of nanoadsorbent for preconcentration and extraction of Cr (VI) was 96 %, whereas it was less than 5 % for Cr (III).Good recoveries, with low detection limits and good preconcentration factors are the main advantages of this procedure.

View Article: PubMed Central - PubMed

Affiliation: Occupational and Environmental Health Research Center (OEHRC), Iranian Petroleum Industry Health Research Institute (IPIHRI-PIHO), Tehran, 1485733111 Iran ; Research Institute of Petroleum Industry (RIPI), Tehran, 14665-1137 Iran.

ABSTRACT

Background: Chromium (VI) has toxic and carcinogenic effects. So, determination and speciation of chromium in environmental samples is very important in view of health hazards. In this study, solid phase extraction (SPE) based on bulky amine-functionalized bimodal mesoporous silica nanoparticles (NH2-UVM-7) as a novel nanoadsorbent was applied for preconcentration and speciation of chromium (III, VI) in water samples.

Methods: UVM-7 was synthesized via atrane route and subsequently functionalized with amino silane via grafting method. In SPE procedure, polymer tubing as a micro-column was filled with NH2-UVM-7 adsorbent. Preconcentration and speciation of Cr (III) and Cr (VI) ions with NH2-UVM-7 were obtained in water samples due to the fact that only Cr (VI) ions can be complexed with-NH2 groups at optimized pH. Finally, chromium concentration was determined by flame atomic absorption spectrometry (F-AAS).

Results: TEM, XRD, and SEM results confirmed the beneficial properties of NH2-UVM-7 as the adsorbent for chromium extraction. Under the optimal conditions, linear calibration curve, detection limit and preconcentration factor were obtained 6-320 μg/ L, 1.2 μg/L and 66.7, respectively (RSD < 5 %). The efficiency of nanoadsorbent for preconcentration and extraction of Cr (VI) was 96 %, whereas it was less than 5 % for Cr (III).

Conclusions: The developed NH2-UVM7-based SPE/F-AAS method has enough sensitively and simplicity for speciation and determination of Cr (VI) and Cr (III) ions in real water samples. Good recoveries, with low detection limits and good preconcentration factors are the main advantages of this procedure.

No MeSH data available.


Related in: MedlinePlus