N-Phenylbenzohydroxamic acid (PBHA) and its derivatives are widely employed as gravimetric reagents for many metal ions15• PBHA has also been reported as a reagent for the gravimetric estimation of copper and cobalt6• However it has been found that the introduction of electrophilic substituents like chlo.riine on the N-phenyl ring of the hydroxamic acid renders the reagent more selective due to...

Studies were carried out to evaluate a gravimetric method for the determination of soil organic matter by the mass loss at 300C. The gravimetric method was compared with Walkley-Black, using several brazilian soils with variable chemical and physical properties. Gravimetric method was positively correlated with Walkley-Black method with the following linear regression equation: y = 3.72x + 0.29...

In chemical measurements (for instance in titrimetric analysis) it is very important to precisely measure amount of liquid, the measurement is performed with use of various measuring vessels. Presently laboratories use all kinds of glass measuring vessels like: beakers, flasks, etc., for measurement of bigger volumes of liquid, and in case of small volumes glass pipettes. Glass pipettes have be...

1-Methyl-1H-imidazol-3-ium 2,3,4,5,6-pentafluorophenolate [mim]C6F5O as a novel nano ionic liquid was designed, synthesized and characterized by using various techniques such as Fourier transform spectroscopy infrared (FT-IR), nuclear magnetic resonance (NMR), x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ener...

In these methods, the response of the test organism to graded concentrations of the substance being assayed is determined, after a suitable incubation period, by measurement of the amount of growth in terms of dry cell weight. Under the conditions of assay, this weight is proportional to the concentration of the limiting factor. By comparing the response of the test organism to the sample being...