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Author: search.filters.author.Kumar, Bhajanthri NateshHas files: Yes

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    Analysis of lubricating grease by ICP-OES : a case study on preparation methodology
    (Asian Publication Corporation, 2016-01-30) Marume, Cathrine; Kumar, Bhajanthri Natesh; Redhi, Gan G.
    The aim of this study was to develop simple, cost effective and reliable sample preparation methods for the analysis of lubricating grease samples. Direct dilution, microwave digestion and emulsification methods were designed and compared for the analysis of Ca, B, Al, Na, Mo, Zn and Ba with inductively coupled plasma optical emission spectroscopy (ICP-OES). The direct dilution method gave most inconsistent results in terms of percentage recovery. The optimized microwave digestion and emulsification methods compared well and showed good reliability in terms of sensitivity and selectivity. The calibration curves resulting from oil emulsion has no significant difference with that of aqueous emulsions, but the stability of the emulsified samples was very low. The limit of detection and limit of quantification values obtained from the microwave digestion method were very low and therefore it is superior amongst the three methods for the analysis of various lubricating grease samples.
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    Spectrophotometric determination of Cadmium(II) in water and soil samples using Schiff's bases
    (Asian Publication Corporation, 2016) Kumar, Bhajanthri Natesh; Kumar, S. Himagirish; Redhi, Gan G.
    A simple and rapid method was developed with the two novel Schiff ’s base ligands, (E)-N'-(2-hydroxy-5-nitrobenzylidene)isonicotinoylhydrazone and 2-(4-fluoro benzlideneamino)benzenothiol for monitoring the cadmium(II) in different water and soil samples. The two ligands react with cadmium(II) at pH 4.9/5.7 to form pale yellow/pale brown complexes with stoichiometric ratios of 1:1 (M:L). The complexes obeyed Beer’s law in the range of 2.0 and 2.5 mg L-1 with an excellent linearity in terms of the correlation coefficient of 0.99. The molar absorptivity and Sandell’s sensitivity of the complex systems were found to be 3.68 × 104, 4.32 × 104 L mol-1 cm-1 and 0.00298, 0.0034 μg cm-2, respectively. The limit of detection for cadmium(II) was noted as 0.042 and 0.063 μg L-1, respectively for these ligands. Furthermore, in vitro antimicrobial activities of both ligands and their complexes were successfully examined and reported.