Browsing Faculty of Health Sciences by Author "Mbongwe, B."
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Mmualefe, L.C.; Torto, N.; Huntsman-Mapila, P.; Mbongwe, B. (Elsevier Ltd, http://www.elsevier.com/locate/microc, NaN, 2009)[more][less]
Abstract: Headspace solid phase microextraction (HS-SPME) was optimized for the analysis of pesticides with gas chromatography electron capture detection (GC-ECD) and high-resolution mass spectrometry. Factors influencing the extraction efficiency such as fiber type, extraction mode and temperature, effect of ionic strength, stirring and extraction time were evaluated. The lowest pesticide concentrations that could be detected in spiked aliquots after HS-SPME–GC-ECD ranged from 0.0005 to 0.0032 μg L−1. Consequently hexachlorobenzene, trans-chlordane, 4,4′-DDD and 4,4′-DDE were detected in water samples after HS-SPME at concentrations ranging from 2.4 to 61.4 μg L−1 that are much higher than the 0.1 μg L−1 maximum limit of individual organochlorine pesticides in drinking water set by the European Community Directive. The same samples were cleaned with ISOLUTE C18 SPE sorbent with an optimal acetone/n-hexane (1:1 v/v) mixture for the elution of analytes. No pesticides were detected after SPE clean-up and pre-concentration. Precision for both methods was satisfactory with relative standard deviations less than 20%. This work demonstrated the superiority of HS-SPME as a sample clean-up and pre-concentration technique for pesticides in water samples as well as the need to identify and control point sources of pesticides. URI: http://hdl.handle.net/10311/851 Files in this item: 1
Mbongwe_MJ_2009.pdf (786.8Kb) -
Mbongwe, B.; Mmereki, B.T.; Magashula, A. (Elsevier Ltd. http://www.elsevier.com/wps/find/journaldescription.cws_home/404/description#description, March 12, 2007)[more][less]
Abstract: Healthcare waste management continues to present an array of challenges for developing countries, and Botswana is no exception. The possible impact of healthcare waste on public health and the environment has received a lot of attention such that Waste Management dedicated a special issue to the management of healthcare waste (Healthcare Wastes Management, 2005. Waste Management 25(6) 567-665). As the demand for more healthcare facilities increases, there is also an increase on waste generation from these facilities. This situation requires an organised system of healthcare waste management to curb public health risks as well as occupational hazards among healthcare workers as a result of poor waste management. This paper reviews current waste management practices at the healthcare facility level and proposes possible options for improvement in Botswana. URI: http://hdl.handle.net/10311/223 Files in this item: 2
license.txt (1.998Kb)
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