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

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

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

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

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

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

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