Articles written in Proceedings – Section A
Volume 1 Issue 12 June 1935 pp 887-890
The Cambodia cotton flowers (
Volume 2 Issue 5 November 1935 pp 490-496
The flower petals of the Uppam cotton plant (
Volume 4 Issue 1 July 1936 pp 54-58
A preliminary examination, using a small sample of the flower petals of the Karunganni (
Volume 5 Issue 4 April 1937 pp 357-364
Herbacitrin, the new flavonol glucoside obtained from
Volume 6 Issue 1 July 1937 pp 12-15
An attempt has been made to fix the position of the glucose residue in gossypitrin by methylation with diazomethane and hydrolysis of the product. It has been found that methylation is incomplete, one hydroxyl group remaining unaffected, and thereby giving after hydrolysis a tetramethyl-gossypetin. This compound probably has the two hydroxyl groups in the 5 and 7 positions.
Volume 13 Issue 2 February 1941 pp 108-115
It has been shown that hydrochloric acid can be used for dissolving lead oxalate precipitates in the estimation of lead and also for the titration of the liberated oxalic acid with permanganate provided the concentration of the hydrochloric acid is not greater than 0·5 N. Employment of hydrochloric acid obviates the difficulties due to occlusion of oxalic acid in Low’s method and the complications in the permanganate titration arising out of the use of nitric acid. Quantitative precipitation of lead as oxalate does not require 60% concentration of acetic acid. Precipitation is complete even when 5–6% of this acid is present. The use of nitric acid in oxalic acid-permanganate titrations has been shown to be not permissible.
Volume 13 Issue 3 March 1941 pp 194-198
The lanthanum nitrate test for the acetate ion has been examined for use in the routine analysis of mixtures of inorganic substances including the acetate, oxalate and tartrate radicles. A distillation method for the preparation of the test solution and a modification of this procedure in the presence of sulphites and thiosulphates are described. The results obtained are quite satisfactory and the test is recommended for general use.
Volume 14 Issue 2 August 1941 pp 105-111
The colouring matter of the flower petals of
Cannabiscetin forms a hexaacetate and a hexamethyl ether. It is a flavonol exhibiting similarities with gossypetin and herbacetin particularly in regard to alkali colour reactions and gossypetone reaction. It yields gallic acid on being subjected to alkali fission, its methyl ether producing trimethyl gallic acid. It is, therefore, concluded to be 3:5:8:3′:4′:5′ hexahydroxy flavone.
Volume 14 Issue 3 September 1941 pp 307-312
Volume 15 Issue 2 February 1942 pp 81-88
Addition of boric acid to O-hydroxy-carbonyl compounds dissolved in concentrated sulphuric acid, except in a few cases, brings about either a marked intensification or a change in colour of the fluorescence exhibited by them in daylight or under the lamp. In a few other cases fluorescence appears for the first time on the addition of boric acid. Since even the simpler O-hydroxy-carbonyl compounds yield these results with boric acid, it appears reasonable to conclude that this reaction will serve as a suitable method for the detection of O-hydroxy-carbonyl group. It must, however, be borne in mind that while the appearance of fluorescence, its intensification or a change in colour indicates the presence of a hydroxyl group ortho to the carbonyl, the non-appearance of the fluorescence effects described does not indicate the absence of this group.
No fluorescence changes are observed with boric acid if the molecule of the compound under investigation does not contain a ketonic group ortho to the hydroxyl, so also in the absence of either of them or when they are present in positions other than ortho to each other.
Sulphonation of the simpler O-hydroxy-carbonyl compounds brings about a marked change in the colour and intensity of the fluorescence; the sulphonic acid group appears to be markedly auxo-floric in character. It is remarkable that nitration or bromination, on the other hand, damps the fluorescence considerably.
From the brilliant fluorescence effects given by resacetophenone, it is expected to develop into a useful reagent for the detection of boric acid on a semi-micro scale.
Further work along these lines is in progress.
Volume 16 Issue 5 November 1942 pp 349-358
A new fluorescence reaction for the detection of boric acid with resacetophenone and phosphoric acid has been described. None of the metallic radicles examined interferes while among the acid radicles chromate, bromate, chlorate, nitrite and fluoride do so to a limited extent. The reaction compares favourably with those described in the literature both as regards limit of identification and also interference. It has been shown that the test is applicable for the detection of micro-quantities of boric acid.
Volume 17 Issue 1 January 1943 pp 26-31
A sample of the flower-petals of
Populnetin seems to be a new tetrahydroxy flavone and populnin is its monoglucoside.
Volume 18 Issue 3 September 1943 pp 171-178
A new method for the approximate colorimetric estimation of boric acid depending on the yellow colouration yielded by boric acid with pentamethyl-quercetin in presence of citric acid in anhydrous acetone medium has been described. The method is empirical in character and gives results with a maximum error of about 15% with quantities of boric acid ranging from 0·4 to 1·8 mg.
Volume 18 Issue 6 December 1943 pp 364-372
Addition of boric acid to aromatic compounds (C, H, and O only) of various types containing the, dissolved in concentrated sulphuric acid generally produces a marked intensification or a change in colour of the fluorescence exhibited by them in daylight or under the lamp In several cases the solution of the compound in sulphuric acid is itself non-fluorescent and fluorescence appears on adding boric acid
In a few cases even when this group is present no fluorescence effects are obtained with boric acid.
3∶7-Dihydroxy-flavone and its 7-methyl ether are exceptions in that they give positive reactions with boric acid even though the above group is absent.
The fluorescence effects obtained with boric acid could be utilised for the detection of the in various types of aromatic compounds containing carbon, hydrogen and oxygen only. A positive reaction indicates the presence of this group but the converse is not true
This reaction is more general than all the others described in literature and is also easily carried out.
Further work is in progress.
Volume 19 Issue 6 June 1944 pp 401-404
Fluorescence reactions with boric acid and
The introduction of bromine atoms into the molecule of an
The fluorescence test for the
Volume 21 Issue 1 January 1945 pp 45-55
Volume 21 Issue 4 April 1945 pp 1- Erratum
Volume 21 Issue 6 June 1945 pp 272-279
Volume 23 Issue 1 January 1946 pp 16-22
The introduction of the azo-group into the molecule of an
The fluorescence test for the
Volume 24 Issue 5 November 1946 pp 448-450
The magnesia and residual manganese have been precipitated together with oxine, the content of the latter determined colorimetrically and that of the former calculated by difference in the analyses of samples of charnockite, leptynite and garnet. The results obtained are compared with those obtained in parallel determinations carried out by the pyrophosphate method and improved accuracy in the estimation of residual manganese as well as magnesia claimed.
Volume 25 Issue 2 February 1947 pp 159-161
Volume 25 Issue 5 May 1947 pp 404-407
Sixty samples of samarskite were collected from a mica pegmatite vein in Nellore district, S. India.
The physical and chemical properties of six representative samples from this collection were studied.
Numbers 1 and 6 of the selected samples of samarskite were intergrown with Columbite-Tantalite.
The specific gravity of these six specimens varies from 5·567 to 5·776. The hardness is between 5 and 6. The colour varies from dark steel grey to velvet-black and the streak is generally brown to dark-brown. They all break with conchoidal fracture.
Specimen No. 1 which is an intergrowth of samarskite with Columbite-Tantalite was polished and placed in contact with a panchromatic photographic plate. Only the samarskite portion affected the photographic plate.
The chemical analysis of samarskite shows a variation in UO3 percentage from 4·2 to 10·5% and the Nb2O5+Ta2O5 from 53·4 to 69·7%. Attention is drawn to the fact that the UO3 percentages of samarskite from the Nellore area differ from those of North Carolina.
Volume 27 Issue 1 January 1948 pp 29-32
A typical sample of samarskite has been analysed and the results reported.
The thoria content of the sample is 1·98%.
The percentage of cerium earths present in this sample is relatively much smaller than found in samples from North America. Our sample contains 0·4% ceria.
Hexavalent uranium has not been found in the sample but this is of no special significance.
The radium contents is 1·0 gr. in 39· 71 tons and the Nellore samarskite is nearly as rich as Katanga Carnotite in this element.
Volume 27 Issue 2 March 1948 pp 138-140
An upper limit of identification exists for the lanthanum nitrate test for acetate.
A definite blue colour is obtained in the test for concentrations of acetic acid ranging from 120 mg. to 0·2 mg. per c.c.
Volume 27 Issue 3 March 1948 pp 202-208
Precipitates of manganese oxyquinolinate obtained from a mineral acid solution containing a slight excess of oxine by adding dilute ammonia, according to Berg’s second method, could be dried to constant weight at 150° C. and weighed. A slight superficial discoloration which may be observed in some cases is inappreciable even when dealing with small amounts of manganese. The composition of the dried precipitate corresponds to Mn (C9H6ON)2 and contains 16·03% manganese.
Satisfactory results are obtained in a single precipitation provided a large excess of oxine is not added. A large excess of oxine with or without the addition of strong ammonia tends to yield higher results. Double precipitation does not improve the accuracy of the results in such cases.
The presence of large amounts of ammonium or sodium chloride does not appreciably affect the accuracy of the results.
Small amounts of manganese ranging from 0·3 to 4·0 mg. could be satisfactorily determined in presence of large amounts of sodium chloride and strong ammonia.
Volume 35 Issue 2 February 1952 pp 72-74
Quantitative studies on the bromination of resacetophenone showed that the reaction was slow and progressive and its magnitude depended primarily on the amount of bromate initially added in excess of the theoretical equivalent so that reproducible results could not be obtained directly by Koppeschaar’s method. However, on plotting the volume of bromate initially added against the excess found by titration, a linear graph was obtained which on extrapolation to zero excess gave the value of bromate equivalent to di-bromination of the ketone present in solution. The estimated maximum error involved was of the order of 5%.
Volume 36 Issue 2 August 1952 pp 123-127
The volumetric determination of manganese with 8-hydroxy-quinoline was investigated. Errors due to adsorption have been shown to increase with increase in (