Analytical Methods in Environmental Chemistry Journal
Volume:2 Issue: 4, Dec 2019

In this research, the bismuth oxide (Bi 2 O 3 ) nanostructures were prepared via chemical method at 90 °C for 3 h. the results samples were characterized by Fourier transform infrared (FTIR) for determination of functional groups, X-ray diffraction (XRD) for evaluation of crystal structure, dynamic light scattering (DLS), scanning electron microscope (SEM) for presentation of morphology and size, energy-dispersive X-ray spectroscopy (EDS) for determination of chemical composition, and diffuse reflection spectroscopy (DRS) for ultraviolet (UV) blocking. Also, the Bi 2 O 3 nanostructures were used for benzene extraction from waters in pH=5-7. By procedure, 30 mg of Bi 2 O 3 mixed with hydrophobic ionic liquid ([HMIM][PF6]) and injected to water samples. After shaking and centrifuging, benzene removed from water by ionic liquid-micro solid phase extraction (IL-μSPE) and determined by gas chromatography with flame ionization detector (GC-FID). The absorption capacity and recovery was obtained 167.8 mg per gram of Bi 2 O 3 and more than 96%, respectively. Based on the results, the bismuth oxide nanostructures were observed with rod morphology and the diameter of nanometer. The antibacterial activities of the samples were determined against Salmonella using inhibition zone diameter. Based on the study, bismuth oxide nanostructures have good potential for removal of benzene from waters. By IL-μSPE method, the results validated by spiking of samples

The biosorption of metanil yellow on hen egg membrane from aqueous solution in a batch process was investigated at 29 o C with a view to determine the potential of the membrane in removing metanil yellow from aqueous solution. The effects of contact time, initial biosorbate concentration, biosorbent dosage and initial biosorbate pH were determined. Various isotherm models were used to analyze experimental data. The highest experimental equilibrium biosorption capacity obtained was 129.88 mg g -1 . The optimum pH was 3. Adsorption capacity increased with increase in initial solution concentration but decreased with increase in time. The isotherm models applied were good fits based on correlation coefficients. Flory-Huggins isotherm was the best fit (R 2 =0.986). The biosorption was endothermic, good, physisorptive and spontaneous. This work shows that hen egg membrane is a potential biosorbent for the removal of metanil yellow from aqueous solution. Removal of metanil yellow by batch biosorption Beniah Obinna Isiuku et al Analytical Methods in Environmental Chemistry Journal Vol 2 (2019) 15-26

In this study, the effects of nanostructure absorbent of zinc oxide (ZnO) in graphene bed for wastewater treatment were studied. Initial analysis was undertaken to identify the existing metals and their concentration in the prepared wastewater. It was seen that the diluted solution consisted of the ambivalence ions of lead, copper, nickel, cadmium, and silver with the concentration of 73.31, 81.19, 54.6, 98.1and 76.1 milligram per liter, respectively. Trivalent chrome, with a concentration of 98.1 milligram per liter was also observed. Therefore, by adding various amounts of absorbent (20, 30 and 50 mg) to the wastewater sample and adjusting the pH to 5 and 6, each metal was separately absorbed. Consequently, the concentration of the remaining metals was measured, and it was observed that absorbent was effective for the absorption of lead, copper and silver (with a reduction of up to 80%), however, the absorbent was weak in the absorption of nickel and chrome. Hence, the silicon nanoparticles added to absorbent and the experiments repeated. It was observed that the presence of silicone resulted in higher absorption of nickel and chrome but negatively affected the absorption of copper and silver. Electrical charges at lower pH’s have an inverse impact on the absorption of metal ions that is due to the electrostatic repelling forces between the positive charges. In more acidic solutions, the carbonyl groups in the surface of composite create positive charges and hence repel the metal ions. Hence, the performance of the absorbent improves by reducing the acidity of the solution. At the pH of six, the number of hydroxide increases and the capacity of absorbing metal cations increase. Absorption of heavy metals by nanotechnology Ahmad Ghozatloo et al Analytical Methods in Environmental Chemistry Journal Vol 2 (2019) 27-38

A novel analytical method based on centrifuging dispersive liquid-liquid microextraction (CD-LLME) procedure for pre-concentration of As (III) has been developed prior to determine by hydride generation atomic absorption spectrometry (HG-AAS). In this method, 0.1 g of a task specific ionic liquids (methyltrioctylammonium 2-mercaptobenzoate; TOMAS; TSIL) as the extracting and complexing solvent and acetone as dispersant solvent were rapidly added into the water and blood samples at pH 4.5. The As (V) is simply calculated by difference between total concentration and inorganic forms As (III) in liquid samples. By optimizing parameters, the enrichment factor (EF) was obtained 9.8 and 49.6 for blood and water samples, respectively. The limit of detection (LOD) of 22.4 ngL-1 and 4.3 ngL-1 were achieved for 10 mL and 50 mL of As(III) in blood and water samples, respectively (RSD<%5). The real samples were validated by certified reference material (CRM) by proposed procedure

Mercury as a toxic heavy metal is important factor must be determined and controlled in work place air and human biological samples. It should be mentioned that, mercury (Hg) get distinguished from other toxic environment pollutants, due to their non-biodegradability which accumulate in living tissues of human body. By NIOSH method, the briefing work place air of worker was measured by flow injection cold vapor atomic absorption spectrometry (FI-CV-AAS). For separation and preconcentration mercury from blood/urine samples, a new procedure based on benzyl 1H-pyrrole-1-carbodithioate (BPDC; C12H11NS2) was used by ultrasonic liquid-liquid micro-extraction (ULLME) coupled with cold vapor atomic absorption spectroscopy (CV-AAS). The influences of various analytical parameters including pH, BPDC concentration, sample volume and ionic liquid volume were investigated. The quantitative recoveries and enrichment factor were obtained more than 95% and 9.8, respectively at pH=7. The detection of limit (LOD) and detection of quantification (LOQ) of mercury were 30 ng L-1 and 0.1 μg L-1 respectively. In order to calculate the validation and accuracy of proposed method, the certified reference materials (NIST, CRM 3133 Lot 061204) was used and analyzed by ULLME-CVAAS. So, proposed method had good potential for preparation and preconcentration mercury in human blood / urine samples of worker and workplace air before analysis.Analysis in occupational health Ali Ebrahimi et alAnalytical Methods in Environmental Chemistry Journal Vol 2 (2019) 49-58

Luminescent graphene quantum dots(GQDs)and multi wall carbon nanotubes (MWCNTs) as photocatalytic sorbent based on was used for removal of toxic ethylbenzene from air in present of UV-radiation. A novel method based on solid gas removal (SGR) based on GQDs and MWCNTs as an efficient adsorbent was used for ethylbenzene removal from air in Robson quartz tubes (RGT). After synthesized and purified of GQDs and MWCNTs, a system was designed for generation of ethylbenzene in air with difference concentrations, and then the mixture was moved to quartz tubes with UV radiation in optimized conditions. The ethylbenzene in air was absorbed on the 25 mg of GQDs or MWCNTs, desorbed from sorbent at 146oC and determined by GC-FID. The main parameters such as, temperature, ethylbenzene concentration, amount of GQDs / MWCNTs and flow rate were studied and optimized. The recovery of ethylbenzene removal from air (more than 95%) and absorption capacity of adsorbent (186.4 mg g-1) were achieved in present of UV radiation at room temperature by GQDs. The flow rate and temperature were obtained at 300 mL min-1and less than 42 0C, respectively. Based on results, the special surface area and favorite porosity of GQDs caused to efficient removal of ethylbenzene from air in present of UV as compared to other carbon compounds such as MWCNTs, and graphene.Removal of ethylbenzene from air Baharak Bahrami Yarahmadi et alAnalytical Methods in Environmental Chemistry Journal Vol 2 (2019) 59-70

A mixture of captopril nanoparticles (CAP-NPs) and ionic liquid (IL, [HMIM] [PF6]) paste on micro graphite rod (CAP-IL-MGR) and was used for separation cadmium in human serum and urine samples by micro solid phase extraction (μ-SPE). 0.01 g of CAP-NPs and 0.1 g of [HMIM] [PF6] mixed with 1 mL of acetone and mixture passed physically on micro graphite rod (MGR) at 55oC. Then, the graphite probe placed on 10 mL of human biological samples with 5 min of sonication, then cadmium ions complexed by thiol group of captopril (CAP-SH) at pH=5.5. The cadmium ions on micro probe were back extracted with 0.25 mL of nitric acid (0.5 M) which was diluted with DW up to 0.5 mL and finally, the cadmium concentration determined by ET-AAS. By optimizing of amount of captopril, the absorption capacity and recovery were obtained 132.4 mg g-1 and more than 96%, respectively. The limit of detection (LOD), linear range (LR) and enrichment factor (EF) were achieved 2 ngL-1, 0.01-0.35 μg L-1and 19.7, respectively (RSD %<5%). The validation was done by certified reference material (CRM, NIST) and ICP-MS analysis