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1.
Upadhyay R. K. Bansal Rashmi R. Vajpai Usha 《Monatshefte für Chemie / Chemical Monthly》1976,107(5):1221-1225
Thin layer chromatographic behaviour of ten anils was studied on silica gel adsorbent mixed with starch binder with ten solvent systems. Simultaneous separation, identification and determination of ternary mixtures of isomers was stressed. TheR
F
increasing order was found to be dependent on the solvent and independent of the degree of saturation of the chamber. The correlations ofR
F
with max and (C=O) of isomers were established and used in their identification. Six anils were separated in methanol—benzene (11). 相似文献
2.
The microgram detection and determination of picric acid with sodium hypochlorite solution is based on its oxidation in alkaline solution and chlorination with excess of chlorine present in hypochlorite solution. A characteristic orange color is obtained, which can be used as a specific test. The sensitivity of the picric acid was enhanced by performing the resin spot test. This color reaction was applied for the determination of picric acid spectrophotometrically. 相似文献
3.
Michael additions of a β,γ-unsaturated ester and a nitrile to a variety of α,β-unsaturated ketones can be effected with high regioselectivity and in good yields using P(i-PrNCH2CH2)3N as a catalyst. 相似文献
4.
A procedure has been developed for the direct fourth-derivative spectrophotometric determination of iron(III) dimethyldithiocarbamate by converting it into an iron(II) 2,2'-bipyridyl complex, which is then dissolved in Triton X-100. Beer's law is obeyed over the concentration range 0.5-20 microg mL(-1 )in the final solution. Various parameters such as the effect of pH and interference of large number of ions on the determination of ferbam have been studied in detail. The method is sensitive, highly selective and can be used for the determination of ferbam in a commercial sample and in mixtures with various dithiocarbamates (ziram, zineb, maneb, etc.) and from wheat grains. 相似文献
5.
Preparation and some reactions of the first cumulated ylide of arsenic, viz. triphenylarsoranylideneketene are described. 相似文献
6.
Sanyal A Rautaray D Bansal V Ahmad A Sastry M 《Langmuir : the ACS journal of surfaces and colloids》2005,21(16):7220-7224
We show here that reaction of the fungus, Fusarium oxysporum, with the aqueous heavy-metal ions Pb2+ and Cd2+ results in the one-step formation of the corresponding metal carbonates. The metal carbonates are formed by reaction of the heavy-metal ions with CO2 produced by the fungus during metabolism and thus provide a completely biological method for production of crystals of metal carbonates. The PbCO3 and CdCO3 crystals thus produced have interesting morphologies that are shown to arise because of interaction of the growing crystals with specific proteins secreted by the fungus during reaction. An additional advantage of this approach is that the reaction leads to detoxification of the aqueous solution and could have immense potential for bioremediation of heavy metals. Under conditions of this study, the metal ions are not toxic to the fungus, which readily grows after exposure to the metal ions. 相似文献
7.
Pinacol Formation and Reduction of Aromatic Carbonyls with Magnesium–Methanol at Ambient Temperature
Jitender M. Khurana Geeti Bansal Gagan Kukreja Ravi R. Pandey 《Monatshefte für Chemie / Chemical Monthly》2003,421(5):1365-1371
A simple and inexpensive procedure for the pinacol formation of aromatic aldehydes and reduction of aromatic ketones to the corresponding alcohols with magnesium in dry methanol at ambient temperature is reported. The pinacol formation and reduction are proposed to be proceeding by SET from magnesium. 相似文献
8.
A sensitive and inexpensive method of spectrophotometric determination of chromium(VI), based on the absorbance of its complex with malachite green and acetic acid at pH 2.5 is reported. The complex shows a molar absorptivity of 8 x 10(4) l.mole(-1) cm(-1) at 560 nm, using malachite green and acetic acid as reference solution. The effect of time, temperature, pH and reagent concentration is studied and optimum operating conditions are established. Beer's law is applicable in the concentration range 2.0-22.8 mug/ml chromium(VI). The resin beads act as a catalyst and as little as 1.6 mug of chromium(VI) is detected in the resin phase as compared to 4.1 mug in the solution phase. The standard deviation in the determinations is +/-0.40 mug/ml for a 10.35 mug/ml solution. 相似文献
9.
S. Vatsala V. Bansal D. K. Tuli M. M. Rai S. K. Jain S. P. Srivastava A. K. Bhatnagar 《Chromatographia》1994,38(7-8):456-460
Summary Hydrazine, an oxygen scavenger in boiler water, was derivatised to the corresponding acetone azine and determined at the ng ml–1 level by gas chromatography. Morpholine, a corrosion inhibitor used in steam boilers, was estimated either directly (if >2.0 g ml–1) or by quantitative preconcentration (0.1 ng – 2.0 g ml–1). To obtain symmetrical peaks for these amines, the column packing was coated with KOH. Use of a nitrogen-specific detector improved accuracy of estimation of hydrazine and morpholine, giving a RSD of 1.9–3.6%. Chromatographic analysis of these amines in boiler feed water and steam condensate samples collected from boilers servicing a petroleum refinery is described. Environmental safety regulations calls for monitoring of hydrazine and the methods developed can easily be adapted for this purpose. 相似文献
10.
Conditions have been developed for the determination of chromium after extraction of its phenanthrenequinone monoximate into molten naphthalene in the presence of potassium chloride. The solidified naphthalene-containing chromium complex was dissolved in chloroform and the trace amounts of chromium determined spectrophotometrically. Beer's law holds in the concentration range of 5.2–84.3 μg in 10 ml of the chloroform solution. The molar absorptivity and sensitivity (for an absorbance of 0.001) are calculated to be 6.65 × 103 liters mol−1 cm−1 and 0.00782 μg/cm2. Ten replicate solutions containing 31.2 μg of chromium(III) gave a mean absorbance of 0.399 with a relative standard derivation of 0.00497. Interference of various ions has been studied and the method applied for the determination of chromium(III) in certain alloys. 相似文献