Removal, preconcentration and determination of Mo(VI) from water and wastewater samples using maghemite nanoparticles

Author(s):  
Abbas Afkhami ◽  
Rasoul Norooz-Asl
2001 ◽  
Vol 35 (6) ◽  
pp. 1223-1230 ◽  
Author(s):  
Jocelyn C. Dunphy ◽  
Daniel G. Pessler ◽  
Stephen W. Morrall ◽  
K. Alex Evans ◽  
David A. Robaugh ◽  
...  

Separations ◽  
2021 ◽  
Vol 8 (12) ◽  
pp. 235
Author(s):  
Rajmund Michalski ◽  
Paulina Pecyna-Utylska

Due to the increasing environmental awareness of the public, green chemistry has become an important element of environmental protection. In laboratories around the world, millions of analyses of inorganic and organic anions and cations in water and wastewater samples, and solid and gaseous samples are performed daily. Unfortunately, these activities still generate large costs, including environmental costs, which are related to the scale of the studies, the use of toxic chemical reagents, the waste generated, and the energy consumed. The methods used so far for inorganic ion analysis, including classical methods, are increasingly being replaced by instrumental methods, primarily based on ion chromatography. This paper presents the most important advantages and limitations of ion chromatography, and compares them with the costs of classical analyses for the analytes and sample types. Both the financial and environmental costs associated with the determination of common inorganic ions, such as Cl−, NO2−, NO3−, and NH4+, in 1000 environmental samples, were compared using selected reference wet classical methods and ion chromatography. The advantages and limitations of ion chromatography that allow this separation technique to be classified as a green analytical chemistry method have been described herein.


Author(s):  
*Ahmad Ghozatlu

       In this study, the surface modification of graphene (SMG) was developed for efficient speciation and determination of chromium in water and wastewater samples. By procedure, the chromium ions were extracted from water/wastewater samples based on sulfonated and amine graphene (S-NG, N-NG) by suspension solid-phase microextraction procedure (SMSPE). Hydrophobic ionic liquid ([HMIM] [PF6]) was used for separation graphene from 10 mL of water. After shaking and centrifuging, the phase of Cr→ S-NG, Cr→N-NG was back-extracted by 0.2 mL of HNO3 (0.4 mol L-1) and finally chromium concentration determined with ET-AAS. The results showed the sulfonated and amine graphene can successfully extract Cr(III) and  Cr(VI) from water and wastewater samples at pH=3.5-5.5 and pH<3, respectively. Also, the most Cr(VI) extracted by N-graphene at pH=2(NH3+→Cr2O7─). Under the optimal conditions, the linear range, LOD, and preconcentration factor were obtained 0.02–2.4 µg L−1, 5.0 ng L−1 and 20.2, respectively for Cr(III, VI) (%RSD<5%). 


Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1581 ◽  
Author(s):  
Hryniewicka ◽  
Starczewska ◽  
Gołębiewska

Dispersive liquid–liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) was applied to isolate budesonide (BUD) and sulfasalazine (SULF) from aqueous samples. The effects of different parameters on the efficiency on the extraction such as type of extrahent and dispersive solvent, ionic strength, pH of sample, and centrifugation time were investigated. Moreover, the influence of foreign substances on a studied process was tested. The calibration curves were recorded. The linearity ranges for BUD and SULF were 0.022–8.611 µg mL−1 and 0.020–7.968 µg mL−1 with the limit of detection (LOD) 0.011 µg mL−1 and 0.012 µg mL−1, respectively. The enrichment factors (EF) for two analytes were high: for BUD it was 145.7 and for SULF, 119.5. The elaborated procedure was applied for HPLC-UV determination of these analytes in water and wastewater samples.


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