المؤلفون: Naeemullah, Null, Tuzen, Mustafa, Kazi, Tasneem Gul

المصدر: Journal of Industrial & Engineering Chemistry; Jan2018, Vol. 57, p188-192, 5p

مصطلحات موضوعية: PIPETTES, SOLID phase extraction, VANADIUM, MULTIWALLED carbon nanotube synthesis, SURFACE morphology

مستخلص: Simple, rapid and miniaturized portable micropipette tip-syringe solid phase microextraction method was developed for speciation of vanadium in water and food samples. Tetra ethylene pentamine functionalized multiwalled carbon nanotubes were synthesized and packed in micropipette tip-syringe system. The surface morphology of adsorbent was characterized, and the effective factors that influence the efficiency of developed method such as pH, amount of adsorbent, concentration of acid solution for desorption cycles were studied. The V(V) could be adsorbed on the modified adsorbent surface with tetra ethylene pentamine, while V(IV) could not be retained. The assay of V(IV) was based on subtracting values of V(V), from total vanadium. The extracted total vanadium and V(V) were injected directly into the electrothermal atomic absorption spectrometry for analysis. Enhancement factor and detection limit were found 50 and 0.008 μg L −1 , respectively. Accuracy of the method was checked by analysis of certified reference materials. The developed method was applied to water and food samples. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Industrial & Engineering Chemistry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Naeemullah, null, Kazi, Tasneem Gul, Afridi, Hassan Imran, Shah, Faheem, Arain, Sadaf Sadia, Brahman, Kapil Dev, Ali, Jamshed, Arain, Mariam S.

المصدر: Arabian Journal of Chemistry; Jan2016, Vol. 9 Issue 1, p105-113, 9p

مستخلص: In the present study, silver (Ag), cadmium (Cd), nickel (Ni), cobalt (Co) and lead (Pb) were simultaneously determined in water samples of fresh water canal receiving untreated effluents from an industrial area, of Sindh Pakistan. The analytes in the water sample were determined by CPE using ammonium pyrrolidinedithiocarbamate (APDC) as a complexing agent and then entrapped in non-ionic surfactant, octylphenoxypolyethoxyethanol (Triton X-114). The surfactant rich phase was diluted with acidic ethanol prior to analysis by flame atomic absorption spectrometry. The variables affecting the complexation and extraction steps such as pH of sample solution, concentration of oxine and Triton X-114, equilibration temperature and time period for shaking were investigated in detail. The validation of the procedure was carried out by analysis of a certified reference sample of water (CRM1634e). Reliability of the proposed method was also checked by the standard addition method in a real sample at three concentration levels of all metals. Under the optimum conditions, the preconcentration of 10 mL sample solutions, allowed preconcentration factor of 20-fold. The lower limit of detection obtained for Ag, Cd, Ni, Co and Pb was 0.42, 0.48, 0.92, 0.62, and 1.42 μg L −1 , respectively. The proposed procedure was successfully applied to waste and fresh water samples for simultaneous determination of different metals. The concentration of Ag, Cd, Ni, Co and Pb has shown a decreased trend from 46.5–6.96, 23.0–8.92, 30.2–12.8, 14.2–4.45 and 15.3–5.32 μg L −1 , respectively from initial entrance of waste water along the downstream of canal. [ABSTRACT FROM AUTHOR]

: Copyright of Arabian Journal of Chemistry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Shah, Faheem, Naeemullah, null, Kazi, Tasneem Gul, Khan, Rafaqat Ali, Sayed, Murtaza, Afridi, Hassan Imran, Shah, Khizar Hussain, Nisar, Jan

المصدر: Journal of Industrial & Engineering Chemistry; Apr2017, Vol. 48, p180-185, 6p

مصطلحات موضوعية: CADMIUM, MANGANESE, SOLID phase extraction, HEAVY metal absorption & adsorption, ACTIVATED carbon, SERUM albumin

مستخلص: A novel restricted access sorbents based micro solid phase extraction (RAS-μSPE) for the extraction of heavy metal from biological samples has been developed. Cadmium (Cd) and manganese (Mn) were directly extracted skipping the tedious, time consuming and expensive sample preparation step excluding all of the existing proteins. Sorbent’s (activated carbon cloths) surface was modified with bovine serum albumin through glutaraldehyde to make restricted access sorbent (RAS). Different variables affecting the extraction efficiency were selected for optimization. The limits of detection obtained for Cd and Mn were 0.252 and 0.214 μg L −1 , respectively. Analyte recoveries in fortified human whole blood serum and milk samples were found in the range of 90.3–103.9%. The procedure was effectively used for Cd and Mn extraction in real samples devoid of any pretreatment step. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Industrial & Engineering Chemistry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Naeemullah, null, Kazi, Tasneem Gul, Tuzen, Mustafa

المصدر: Journal of Industrial & Engineering Chemistry; Mar2016, Vol. 35, p93-98, 6p

مصطلحات موضوعية: EXTRACTION (Chemistry), CHEMICAL preconcentration, ATOMIC absorption spectroscopy, SEPARATION (Technology), CADMIUM

مستخلص: A novel, simple and rapid single and multi-step cloud point extraction procedure was developed for the selective and simultaneous preconcentration of silver, cadmium and nickel in real samples prior to their determination by flame atomic absorption spectrometry. Dithizone was used as neutral hydrophobic complexing agent. Separation of understudy metals can be achieved by controlling the pH value of the extraction system. Evaluation of the two CPE methods was checked by paired t -test, which indicated a non-significant difference. It was successfully applied to the real water sample. Certified reference materials were used for the accuracy of the green extraction methods. The regression equation for the calibration curve was linear in the range of 10–150 μg L −1 for Ag, 5–100 μg L −1 for Cd, 10–200 μg L −1 for Ni. Relative standard deviation (RSD%) values were found to be lower than 2.5% for all elements. Enhancement factor (EF) and limit of detection (LOD) values were found in the range of 41–58 and 0.27–1.12 μg L −1 , respectively. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Industrial & Engineering Chemistry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Arain, Sadaf S., Kazi, Tasneem G., Afridi, Hassan I., Naeemullah, null, Brahman, Kapil D., Arain, Muhammad B., Panhwar, Abdul H., Arain, Mariam S., Baloch, Shahnawaz

المصدر: Journal of Industrial & Engineering Chemistry; Feb2016, Vol. 34, p27-32, 6p

مصطلحات موضوعية: EXTRACTION (Chemistry), SMOKELESS tobacco, ATOMIC absorption spectroscopy, ARTIFICIAL saliva, COPPER compounds, IONIC liquids, CHEMICAL preconcentration

مستخلص: A green non-dispersive ionic liquid based microextraction (ND-ILμE) method was proposed for the preconcentration of trace levels of copper (Cu 2+ ) in artificial saliva extract (ASE) of smokeless tobacco products (SLT). A 100 cm long, narrow glass column containing aqueous solution of Cu/ASE was used to increase phase transfer ratio by providing more contact area between two medium, which drastically improve the recovery of Cu-PAN complex into ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate [C 4 mim][PF 6 ]. At optimum experimental conditions, the detection limit and the enhancement factor were found to be 0.042 μg L −1 and 85, respectively. This method was successfully applied to real samples. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Industrial & Engineering Chemistry is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)