The antibacterial potential of essential oils and methanol extracts of sweet basil Ocimum basilicum L. (Lamiaceae) was evaluated for controlling the growth range of food-borne pathogenic bacteria. Essential oils extracted by hydrodistillation from the leaves and stems were analyzed by GC-MS. Fifty-seven compounds representing 94.9 and 96.1% of the total leaf and stem oils, respectively, were identified, of which methyl chavicol (36.7 and 29.9%), gitoxigenin (9.3 and 10.2%), trimethoquinol (10.3 and 8.4%), beta-guaiene (3.7 and 4.1%), aciphyllene (3.4 and 3.0%), alizarin (3.2 and 4.4%), naphthaline (2.2 and 3.8%), (-)-caryophyllene (2.0 and 1.9%), and mequinol (1.6 and 1.8%) were the major compounds. The essential oils (10 microL/disc of 1:5, v/v dilution with methanol) and methanol extracts (300 microg/disc) of O. basilicum displayed a great potential of antibacterial activity against Bacillius cereus, B. subtilis, B. megaterium, Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Shigella boydii, S. dysenteriae, Vibrio parahaemolyticus, V. mimicus, and Salmonella typhi with their respective zones of inhibition of 11.2-21.1 mm and MIC values of 62.5-500 microg/mL. The results of this study suggest that the natural products derived from O. basilicum may have potential use in the food and/or pharmaceutical industries as antimicrobial agents.

A preliminary investigation using gas chromatography-mass spectrometry (GC-MS) to analyze the nicotine contained in tobacco leaves was carried out. Nicotine is an alkaloid and tobacco leaves was extracted with methanol and determined by GC-MS. The detection limit for nicotine was at the ppm level for non selective monitoring and the nanogram level for selective detection. This is a simple chromatography-mass spectrometry method for the analysis of nicotine in tobacco leave. Compared to other currently utilized methods for the detection of nicotine in tobacco leaves, the GC-MS provided advantages of high sensitivity, nicotine specific detection and lower instrumentation cost.

No abstract

No abstract

determined the concentration of dissolved hydrocarbons in some parts of the Northern Indian Ocean and found values in the range of 0.6 to 26.5 µg l -1 . Higher values were recorded along the oil tanker route compared with the coastal region from the surface about 10 m depth. The concentration of hydrocarbon in lake water was measured by Starnes et al. 2 The total hydrocarbon content was determined as 1.6 µg l -1 . A 4.5 m long column packed with 2% SE-30 on Chromosorb G was employed for this analysis. The temperature program: 60˚C at the rate of 8˚C min -1 to 275˚C with helium gas flow rate 50 ml min -1 , was used. Normal paraffins over the carbon range C 15 -C 31 were predominant, whereas lower hydrocarbons (C 9 -C 13 ) were unidentified. The seasonal variation and distribution of n-alkanes in water were studied by Sadd and co-workers. Temperature variations including evaporation, bacterial degradation and adsorption as well as photochemical oxidation are postulated to produce pronounced seasonal variations of n-alkanes in water. The n-alkanes showed a regular distribution pattern of the odd and even carbon number compounds between C 13 to C 34 with additional characteristics associated with biological phenomena; abundance of C 17 and C 19 of algal origin and C 25 , C 27 plant inputs were evident. In this study, the water of Buriganga river is considered. This river surrounds flows through the capital of Bangladesh and has enormous impact over socio-economic and other developments of the country in different ways. As a result, the water is continually polluted by different types of compounds through influx of land-base and other sources and put an alarming signal about the water pollution. One of such compounds in the water is hydrocarbon or oil pollutant. The hydrocarbons and its derivatives may enter the river water from a number of sources e.g., shipping or marine activities which include tanker washing sewage, ship scraps particles, oil spillage etc. The use of polluted water makes a lot of problems for human health, aquatic lives and also amenity losses. Now a general demand is that this pollution has to be controlled and the concentration levels of different pollutants in the river water have to be determined. We reported the determination of phenol 4 in aqueous medium and pesticides 5 in other environmental matrices 6,7 by GC. We also analyzed the phenolic antioxidants 8 , river water residues 9 and high molecular weight substances 10,11 by hyphenated and other techniques. This paper will describe the preliminary levels of normal saturated hydrocarbons (C 10 -C 24 ) at different depth of water at various stations of the Buriganga river in Bangladesh. The concentrations of normal saturated hydrocarbons (C10 -C24) were determined in water at the stations of Postagolla, Sadarghat and Sowarighat of the Buriganga river, Bangladesh. Samples were collected from different water depths (5 and 25 cm) of the sampling stations. Hydrocarbons were extracted from these water samples (500 ml) into 70 ml hexane which wer...