http://dr.lib.sjp.ac.lk/handle/123456789/10451 Wed, 07 Jan 2026 06:07:45 GMT 2026-01-07T06:07:45Z http://dr.lib.sjp.ac.lk/handle/123456789/10537 Method Validation for Analysis of Aroclor 1260 in Transformer Oil using Gas Chromatography – Electron Capture Detection Jeevanantham, J.J.; Dissanayake, D.A.T.W.K.; Liyanaarachchi, G.V.V. Since early 1980’s, the production and usage of Polychlorinated biphenyls (PCBs) have been banned throughout the world due to its carcinogenicity to humans and animals. However, due to the large half-lives of PCBs, large amounts of stocks are still available in storage. This study presents the validation data of the method developed for analysis of Aroclor 1260 in transformer oils in order to determine the concentrations for systematic disposal and destruction. The transformer oil samples were prepared according to the ASTM D 4059 with few modifications. PCBs in transformer oils were extracted with iso-octane followed by deactivated florisil cleanup and detection by GC – ECD using HP 5 GC column (30 m x 0.32 mm x 0.25 μm). The study was performed under matrix matched condition to eliminate the matrix effect that was found to be significant. The method was found linear over a wide working range from 2.5 ppm – 100 ppm with a regression coefficient of 0.994 and a lower limit of determination of 2.5 ppm. Method showed satisfactory repeatability with relative standard deviation below 7% over the entire working range. Accuracy of the method was assured using spike recoveries at 5 ppm, 10 ppm and 50 ppm with 85%, 105% and 93% respectively. The selectivity of Aroclor 1260 was confirmed against Aroclor 1254 and Aroclor 1242 considering uniquely identified non – overlapping chromatographic peaks. Based on the performance characteristics, this method can be suggested as an accurate and precise methodology to analyze Aroclor 1260 present in transformer oil. Tue, 01 Jan 2019 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/10537 2019-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/10536 Altitude and Ecological distribution of genus Litsea (Lauraceae) in Western Ghats of Karnataka, India Srinivas, S.G.; Krishnamurthy, Y.L. India is a subcontinent in the world with varied climatic regions, topographic variation results in the very diverse ecological diversity. Litsea is a largest genus in the family Lauraceae differentiated by its dioecious nature, distributed in tropical and subtropical regions which is influenced by some environmental factors. Present research work focussed on distribution of genus in the central Western Ghats of Karnataka, India. Litsea species were collected from 2013 to 2018 in different sampling sites. A total of 12 species were identified and reported from this region. The diversity indices of Litsea vary from species to species as well as region to region. L. floribunda is frequently distributed in all the study sites and it showed highest density when compared with other species, whereas, L. deccanensis distributed only in Sakaleshpur region and it showed lower diversity. The highest number of Litsea species occurred in Sakaleshpur region (10 species) and Mullayyanagiri region having only one species that is L. floribunda. The results indicate that Litsea distribution and diversity is rich in moderate rainfall regions of Western Ghats. The macro and micro nutrients of the soil in the study area reflects the distribution of the genus. There is a gradual increasing in tendency of the species richness with increasing elevation when compared with lower elevated regions. The genus also showed more sensitive and positive association with the elevation factor. Tue, 01 Jan 2019 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/10536 2019-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/10533 Studies on the factors that restrict sexual reproduction and fruit setting in Memecylon flavescens – an endangered taxon Tejavathi, D.H.; Sumalatha, B.S.; Nijagunaiah, R. Memecylon flavescens Gamble is an endangered taxon of Nilgiri region of Western Ghats. Extensive survey in the study area- Avalanche, Ooty made during 2015-18 has revealed a few interesting aspects about the sexual reproductive cycle. Fruit setting is substantially very low though profuse flowering occurs. Flowers are hermaphrodite, actinomorphic, tetramerous, pin type and protogynous, favouring cross-pollination. Pollen fertility as assessed by Alexander’s differential staining is about 30%. Sections of flower buds have revealed the infestation by undescribed gallmidge (Diptera: Cecidomyiidae). In 90% of the flower buds observed, gall midge galleries are seen at various levels in the flower bud, destroying the reproductive organs by larval feeding. Hence, negligible fruit setting is mainly due to gallmidge infestation. Protogynous nature and low percent of pollen fertility are added factors aggravating the effect on fruit setting. Tue, 01 Jan 2019 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/10533 2019-01-01T00:00:00Z http://dr.lib.sjp.ac.lk/handle/123456789/10531 Composition analysis of selected Sri Lankan seaweeds Jayakody, M.M.; Vanniarachchy, M.P.G.; Wijesekara, I. Seaweeds are a rich source of health beneficial bioactive nutraceuticals and currently they are under-utilized in Sri Lanka. In the present study, proximate analysis of seaweed varieties Chnoospora minima and Porphyra sp. obtained from Mirissa, Matara, Sri Lanka and Ulva fasciata was taken from Point Dondra Matara, Sri Lanka on June, 2018 were investigated. The moisture content, total fat content, protein content and ash content were determined according to the Official methods of Analysis by Association of Official Analytical Chemists after drying for 8h at 600 C. The results revealed that the moisture contents (%) of Chnoospora minima, Porphyra sp. and Ulva fasciata were 13.24 ± 0.20, 14.30 ± 0.14 and 18.11 ± 0.01 respectively. Total fat contents (%) of Chnoospora minima, Porphyra sp. and Ulva fasciata were 0.21 ± 0.11, 0.19 ± 0.03 and 0.28 ± 0.05 respectively. Protein contents (%) of Chnoospora minima, Porphyra sp. and Ulva fasciata were 13.70 ± 0.2, 21.14 ± 0.04 and 11.84 ± 0.1. Total ash contents (%) of Chnoospora minima, Porphyra sp. and Ulva fasciata were 17.20 ± 0.24, 5.40 ± 0.7 and 18.05 ± 0.21 respectively. Total carbohydrate content (%) was analyzed according to the Dubois method. Chnoospora minima, Porphyra sp. and Ulva fasciata showed total carbohydrate content (%) as 3.87 + 0.66, 20.59 ± 0.24 and 7.68 ± 1.16 respectively. Moreover, the sulphate content was analyzed according to the precipitate method. Chnoospora minima, Porphyra sp. and Ulva fasciata showed 1.45 ± 0.35, 2.75 ± 0.07 and 4.54 ± 0.06, sulfate contents (%) respectively. In conclusion, highest ash content which indicates a good mineral content was observed in Ulva fasciata and Chnoospora minima. Fibre, protein and carbohydrate contents are significantly different among the 3 samples. Highest fibre content was observed in Chnoospora minima. Highest protein and carbohydrate contents were observed in Porphyra sp. But there is no significant difference in fat contents among the three samples. Tue, 01 Jan 2019 00:00:00 GMT http://dr.lib.sjp.ac.lk/handle/123456789/10531 2019-01-01T00:00:00Z