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91.
2,4‐Dichlorophenoxy acetic acid herbicide is spectrophotometrically determined by diazotization method in a flow injection assembly. The method is based on base hydrolysis of herbicides. The hydrolyzed product 2,4‐dichlorophenol is reacted with diazotized sulfanilic acid. The absorbance of the resulting coloured product was measured at 480 nm. The calibration graph is linear over the range of 0.2–20 μgmL?1, with a relative standard deviation of (RSD) of 7.2% and sample throughput of 90 samples h?1. The % recovery for determination of 2,4‐dichlorophenoxy acetic acid was found to be 92.0–95.3%. The method is easy, simple and faster than the established chromatographic method. The method was applied for determination of 2,4‐dichlorophenoxy acetic acid herbicide in commercial formulations and for residue determination in fruits and food samples. 相似文献
92.
A flow injection spectrophotometric method is proposed for the determination of bromoxynil herbicide. Bromoxynil was hydrolyzed with HCl and the resulting product, 3,5-dibromo-4-hydroxyaniline, was diazotized with nitrite and coupled with aniline. The absorbance of the azo dye was measured at 500 nm. The conditions were optimized for diazotization using FIA. The range of linearity was found to be 0.01 to 5 ppm with a molar absorptivity of 1.27 x 10(5) L mol(-1) cm(-1). The % recovery for the determination of bromoxynil was found to be 91%. The sampling frequency was 80 samples per hour for FIA. The method is simple, fast, and has been successfully applied to the determination of bromoxynil in commercial formulations and food samples. 相似文献
93.
I. O. Abugassa S. O. Abugassa Y. S. Khrbish A. T. Bashir K. Doubali N. Ben Faid 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(3):643-646
Summary The trace elements composition of gallbladder stones samples of the types cholesterol, pigment and mixed stones in addition
to bile have been investigated by k0-instrumental neutron activation analysis (k0-INAA). The samples were obtained from several individuals of adult subjects of the Libyan population who undergone open surgery
of gallbladder (cholecystectomy) at Al-khadra University Hospital in Tripoli. The samples were lyophilized, irradiated together
with Au wire and Zr foil, which serve as flux ratio monitor and a parameter at TNRC. Concentrations of 24 elements in gallstone
and 23 elements in bile were determined. The levels of the trace elements in the various samples investigated are measured
and discussed. The reliability of the analysis was checked with several biological standard reference materials. 相似文献
94.
Fiona Byrne Adriele Prina-Mello Bashir M. Mohamed Yurii K. Gun’ko Yuri Volkov 《Journal of magnetism and magnetic materials》2009,321(10):1341-1345
Nickel nanowires, 20 μm long and 200 nm in diameter, were fabricated by electrodeposition into alumina templates, and characterised by superconducting quantum interference device (SQUID) magnetometer, X-ray diffraction and scanning electron microscopy. Biocompatibility studies of nickel nanowires with differentiated THP-1 cell line-derived macrophages were carried out. From a multiparametric assay, using high content analysis (HCA), the critical time points and concentrations of nickel nanowires on THP-1 cellular response were identified. The nanowires displayed little or no toxic effects on THP-1 cells over short incubation times (10 h), and at low concentrations (<100 nanowires per cell). Our findings indicate the potential suitability of these wires for biological and clinical applications. 相似文献
95.
96.
97.
S. Bashir R. W. McCabe C. Boxall M. S. Leaver D. Mobbs 《Journal of nanoparticle research》2009,11(3):701-706
Forced hydrolysis of Fe(III) ions in acidic media was performed under controlled synthetic conditions to produce α- and β-FeOOH
iron oxides. The forced hydrolysis synthesis was carried out, separately, in an aqueous medium and the lamellar lyotropic
liquid crystalline phase of a commercial non-ionic surfactant/water system. The FT-IR analyses confirmed formation of α- and
β-FeOOH iron oxides in the aqueous and the surfactant media with slight formation of ferrihydrite and haematite. TEM micrographs
have shown that particles formed in the lamellar lyotropic phase are smaller than those produced in the aqueous medium with
their smallest size dimension being constrained in the nanometre scale with a size ranging between 5 and 100 nm. Particles
produced in the nanoscale size appeared to have different optical properties compared to their counterparts produced in the
microscale size. 相似文献
98.
99.
In this paper, we study the dynamics of a stochastic Susceptible-Infective-Removed-Infective (SIRI) epidemic model with relapse. By constructing a suitable stochastic Lyapunov function, we establish sufficient conditions for the existence of an ergodic stationary distribution to the model. Moreover, sufficient conditions for extinction of the disease are also obtained. 相似文献
100.
Abstract A class of non-mesogenic molecules, which as mixtures exhibit monotropic nematic phases, is described. 相似文献