16 research outputs found

    A Novel Micellar Electrokinetic Chromatographic Method for Separation of Metal-DDTC Complexes

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    Micellar electrokinetic chromatography (MEKC) was examined for the separation and determination of Mo(VI), Cr(VI), Ni(II), Pd(II), and Co(III) as diethyl dithiocarbamate (DDTC) chelates. The separation was achieved from fused silica capillary (52 cm × 75 μm id) with effective length 40 cm, background electrolyte (BGE) borate buffer pH 9.1 (25 mM), CTAB 30% (100 mM), and 1% butanol in methanol (70 : 30 : 5 v/v/v) with applied voltage of −10 kV using reverse polarity. The photodiode array detection was achieved at 225 nm. The linear calibration for each of the element was obtained within 0.16–10 μg/mL with a limit of detection (LOD) 0.005–0.0167 μg/mL. The separation and determination was repeatable with relative standard deviation (RSD) within 2.4–3.3% (n = 4) in terms of migration time and peak height/peak area. The method was applied for the determination of Mo(VI) from potatoes and almond, Ni(II) from hydrogenated vegetable oil, and Co(III) from pharmaceutical preparations with RSD within 3.9%. The results obtained were checked by standard addition and rechecked by atomic absorption spectrometry

    HPLC Determination of α-keto Acids in Human Serum and Urine after Derivatization with 4-Nitro-1,2-phenylenediamine

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    The determination of α-keto acids has clinical importance, because these are intermediates in a number of biochemical processes. This work reports the development of an HPLC procedure for the analysis α-keto acids in blood and urine samples after derivatization with 4-nitro-1,2-phenylenediamine (NPD). Nine α-keto acids: glyoxylic acid (GA), pyruvic acid (PYR), 2-oxobutyric acid (KB), 3-methyl-2-oxobutyric acid (MKBA), 3-methyl-2-oxovaleric acid (K3MVA), 2-oxoglutaric acid (KG), 4-methyl-2-oxovaleric acid (K4MVA), 2-oxohexanoic acid (KHA) and phenylpyruvic acid (PPY) were derivatized with (NPD) at pH 3 and separated on a Zorbax 300 SB-C18 HPLC column (4.6x150mm id) and photodiode array detection at 255 nm. The isocratic elution was performed with methanol: water: acetonitrile (42: 56:2, v/ v/ v) with a flow rate 0.9 mL/min. The keto acids separated within 14 min. The method was repeatable with a relative standard deviation (RSD) of 0.1-2.9% for each of the α-keto acids. The limits of detection and quantitation were obtained within the range 0.05-0.26 µg/ mL and 0.15-0.8 µg/ mL respectively. The method was applied for determination of α-keto acids from a pharmaceutical preparation, human serum and urine samples of healthy volunteers and diabetic patients. The results were further confirmed by standard addition technique. The method is rapid and simple and is suitable for the separation and determination of α-keto acids from clinical samples

    Solid-Phase Microextraction and Determination of Tin Species in Beverages and Food Samples by Using Poly (epsilon-Caprolactone-b-4-Vinyl Benzyl-g-Dimethyl Amino Ethyl Methacrylate) Polymer in Syringe System: a Multivariate Study

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    WOS: 000438995800020A new solid-phase microextraction (SP mu E) procedure has been developed for separation and preconcentration of Sn ions by using graphite furnace atomic absorption spectrometry (GFAAS). This technique is based on the complexation of Sn(IV) ions with 1-(2-pyridylazo)-2-naphthol (PAN). The poly (epsilon-caprolactone-b-4-vinyl benzyl-g-dimethyl amino ethyl methacrylate) polymer (PCL vacr) was used as an adsorbent, and it was loaded in micropipette tip of syringe system. Sn(IV) ions were adsorbed on polymer at pH 6. Different experimental conditions were optimized such as pH, amount of complexing agent, and amount of adsorbent. The detection limit (LOD), limit of quantification, preconcentration factor (PF), and relative standard deviation (RSD) were found as 4.5 ng L-1, 13.5 ng L-1, 100, and 3.3%, respectively. Certified reference materials were used to confirm the accuracy of the investigated procedure, and the procedure was successfully practiced for determination of entire concentration of tin within beverages and different food samples.TUBITAK, Government of Turkey, through the 2216 fellowship program; Gaziosmanpasa UniversityGaziosmanpasa University; King Fahd University of Petroleum and Minerals, Research Institute, Center for Environment and Water; Turkish Academy of SciencesTurkish Academy of SciencesRizwan Ali Zounris gratefully acknowledge the financial support from TUBITAK, Government of Turkey, through the 2216 fellowship program for the foreign citizens and providing financial support. Dr. Mustafa Tuzen thank the Gaziosmanpasa University and King Fahd University of Petroleum and Minerals, Research Institute, Center for Environment and Water for their supports. He also thank the Turkish Academy of Sciences for the financial support

    Risk assessment of heavy metals and salts for human and irrigation consumption of groundwater in Qambar city: a case study

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    The study investigated the water quality of groundwater for consumption of human beings and irrigation of taluka Qamber district Qamber-Shahdadkot, Sindh, Pakistan. A total of 21 representative groundwater samples were collected mostly used for human consumption. According to the research work, 81% samples were not suitable for drinking purpose with TDS above the maximum permissible limit of WHO (1000 mg/L). The pH, total phosphate-P, orth ophosphate-P, nitrate-N, nitrite-N, and arsenic were within WHO limits. The concentrations of essential metals more than half samples were higher than WHO guideline. The concentrations of trace metals like Mn, Fe, Co, and Cu of all samples were within WHO limits, but the values of Cr and Ni 52.38%, Cd 57.14%, and Pb 28.57% were above the WHO limits. The concentrations of fluoride in 81% were higher than permissible limits of WHO. The high consumption of water with concentration of salts and fluoride above the permissible limits may be a leading factor of a number of diseases in the area. The water quality determined for irrigation based on Kelly index (KI), sodium percentage (Na%), chloride–sulfate ratio, sodium adsorption ratio (SAR), permeability index (PI), chloro alkaline indices1 (CAI-1), residual sodium carbonate (RSC), and chloride bicarbonate ratio indicated that 25–90% samples were suitable for irrigation purposes

    Capillary Gas Chromatographic Determination of Gamma Aminobutyric acid and Putrescine in Cerebrospinal Fluid using Trifluoroacetylacetone as Derivatizing Reagent

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    In present work, a new capillary gas chromatographic procedure was established and validated for the determination of gamma aminobutyric acid (GABA) and putrescine (Put) using trifluoroacetylacetone (FAA) as derivatizing reagent from Cerebrospinal Fluid (CSF) samples prior to their gas chromatographic- flame ionization detector (GC-FID) analysis. GABA, Put, cadaverine (Cad) and tyramine (TY) as imitative of FAA extracted from the column HP-5 (30 m x 0.32 mm i.d) at temperature 110 ºC for 1 min, tracked by heating rate 25 ºC to 260 ºC /min. The detection was carried out by FID with segregate ratio 10:1, v/v with whole run time 10 min. The proposed method showed linear calibration range between 2.5-50 µg/mL with low limit of detection 1.0 - 2.5 µg/mL analogous to 0.1 ng to 0.25 ng for selected Put, Cad, GABA, and TY. The method based on the pre-concentration was used for the determination of GABA and Put from CSF of human being and amounts found were 0.25- 0.56 µg/mL and 0.16 - 0.41 µg/mL with relative standard deviation (RSD) within 0.8 - 1.1 and 1.1 - 1.5 %, respectively. Many of amino-acids tested, separated completely and did not variate the determinations of GABA and Put

    Vulnerability Assessment & Analysis of Software-Defined Networking using a Virtual Testbed

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    Software-Defined Networking is an advance and modern network architecture that is dynamic, cost-effective, manageable, and adaptable to support the nature of modern applications. Even though SDN solved many limitations and complexities available in traditional networks, the improved network architecture has also bought many new and existing security threats into account. The intruder's aim is to target the central controller, which makes this network the only point of network failure. It is essential to integrate SDN Network with Intrusion Detection System (IDS) to counter the security threats. The proposed work includes developing a virtual testbed for the simulation of the SDN network, where the OVS-switch supporting the OpenFlow protocol is connected to the network topology created using Mininet Simulator. SNORT (signature-based IDS) is integrated with the network to monitor traffic and detect security threats. The vulnerability Assessment of the designed network shows the effective detection of all the major attacks lies in broad attack categories: DoS, Probe, R2L, and U2
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