RP-Department of Chemistry

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1,8-Cineole: An attractant for the banana weevil, Cosmopolites sordidus
(Elsevier, 1996-07) Hassanali, Ahmed; Ndiege, I. O.; Budenberg, W. J.; Otieno, D. O.
1,8-Cineole was identified as one of the electrophysiologically active components of the volatiles from banana cultivars susceptible to the banana weevil. It was also shown to be an attractant for the banana weevil Comopolites sordidus in laboratory behavioural bioassays. The resistant cultivar did not contain 1,8-cineole. β-Phellandrene, which exhibited electrophysiological activity, but did not show any attraction to the banana weevil, was found only in the resistant banana cultivar.
2-Chlorobicyclo[2.2.1]hept-5-ene-2-carboxamide and 2-chlorobicyclo[2.2.1]heptane-2-carboxamide as precursors of bicyclo[2.2.1]hept-5-en-2-one and bicyclo[2.2.1]heptan-2-one: resolution, absolute configuration and hydrogen-bonding properties
(Elsevier, 2005-08-15) Thuo, M. M.; Plettner, Erika; Mohle, Ashley; Griscti, Johanna; Patrick, Brian O.; Nair, R; Batchelor, R. J.; Einstein, F
The absolute configuration of bicyclo[2.2.1]heptan-2-one has not been correlated with a crystal structure of a chemical precursor. The only chemical correlation available had an ambiguity, which could have reversed the assignment. Herein, we report the resolution of 2- hlorobicyclo[2.2.1]hept-5-en-2-exo-carboxamide on a cellulose triacetate column and the crystal structures of the enantiomerically pure and racemic a-chloroamide. We found the absolute configuration (1R,2R,4R) for the (+)-enantiomer of the a-chloroamide. This compound was converted to (+)-bicyclo[2.2.1]hept-5-ene-2-one by base hydrolysis, and the 5,6-unsaturated compounds converted to the saturated congeners. This is the first unambiguous experimental determination of the absolute configuration of bicyclo[2.2.1]heptan-2-one and of cyclo[2.2.1]hept-5-ene-2-one. The three crystal structures of 2-chlorobicyclo[2.2.1]hept-5-en-2-exo-carboxamide reported herein reveal H-bonded dimers, with two distinct orientations of the bicyclic portion relative to the carboxamide dimer. In the racemic crystal, each dimer is composed of two enantiomers, and the bicyclic portions have their bridge carbon atom (C-7) on opposite sides of the H-bonded carboxamide dimer moiety. In the enantiomerically pure crystals, the major dimer had both C-7 atoms on the same side of the carboxamide dimer moiety while the minor dimer had the C-7 atoms on opposite sides. The dimers are present in solution, and can be easily monitored.
2-Hydroxy-4-Methoxybenzaldehyde: Larvicidal Structure-Activity Studies
(2005) Ndiege, Isaiah O; Lwande, Wilber; Akenga, Teresa O; Mahanga, Geoffrey M.
2-Hydroxy-4-methoxybenzaldehyde (1), a compound isolated from Mondia whytei (Hook) Skeels (Asclepiaceae) roots exhibited larvicidal activity (LD5022 mg/mL). A total of 18 other derivatives and closely related congeners revealed varying levels of larvicidal activity. Several closely related congeners, like 2-benzyloxy-4-methoxybenzaldehyde (2), 2-hydroxybenzaldehyde (12), 2-benzyloxybenzaldehyde (3) and benzylphenyl ether (4), showed marked improvement in activity (LD5010, 9, 4.8, 1.2 mg/mL, respectively) against Anopheles gambiae larvae. 2-Benzoyloxy-4-methoxybenzaldehyde (5) exhibited similar activity level (LD50 28 mg/mL) as 1.
A 4-Alkyl-substituted Analogue Of Guaiacol Shows Greater Repellency To Savannah Tsetse (Glossina spp.)
(Springer-Verlag, 2007-05) Hassanali, Ahmed; Saini, R. K.
The responses of Glossina morsitans morsitans Westwood to guaiacol (2-methoxyphenol), a mild repellent constituent of bovid odors, and seven analogues comprising 2-methoxyfuran, 2,4-dimethylphenol, 2-methoxy-4-methylphenol (4-methylguaiacol), 4-ethyl-2-methoxyphenol (4-ethylguaiacol), 4-allyl-2-methoxyphenol (4-allylguaiacol; eugenol), 3,4-methylenedioxytoluene, and 3,4-dimethoxystyrene were compared in a two-choice wind tunnel. The 4-methyl-substituted derivative (2-methoxy-4-methylphenol) was found to elicit stronger repellent responses from the flies compared with guaiacol. None of the other analogues showed significant repellent effects on flies. 4-Methylguaiacol, guaiacol, and eugenol (which was included because of previous reports of its repellency against a number of arthropods) were further evaluated in the field with wild populations of predominantly Glossina pallidipes Austen. The presence of guaiacol or eugenol near odor-baited traps caused some nonsignificant reduction in the number of tsetse catches at relatively high release rates (∼50 mg/hr). In contrast, the 4-methyl derivative at three different release rates (2.2, 4.5, and 9.0 mg/hr) reduced trap catches of baited traps in a dose-response manner. At 10 mg/hr release rate, it reduced the catches of baited and unbaited traps by ∼80 and ∼70%, respectively. In addition, the compound not only reduced the number of tsetse attracted to natural ox odor (∼ 80%), but also had an effect on their feeding responses, reducing the proportion that fed on an ox by more than 80%. Our study shows that the presence of a methyl substituent at the 4-position of guaiacol enhances the repellency of the molecule to savannah tsetse and suggests that 4-methylguaiacol may represent a promising additional tool in the arsenal of techniques in trypanosomiasis control.
Addition of carbenes derived from aryldiazoacetates to arenes using chloro(tetraphenylporphyrinato)iron as catalyst Read More: http://www.worldscientific.com/doi/abs/10.1142/S1088424609000036
(2009-01) Mbuvi, H. M.; Keith Woo, L,
Chloro(tetraphenylporphyrinato)iron, Fe(TPP)Cl, is an active catalyst for the Büchner addition of para-substituted methyl 2-phenyldiazoacetates, 1a–d, to substituted benzenes. Yields greater than 70% have been achieved at temperatures ranging from 60–100°C. Reactions of substituted methyl 2-phenyldiazoacetates with benzene gave rapidly equilibrating mixtures of norcaradienecycloheptatriene valence isomers, 2a–d/2′a–d, in yields over 70%. Treatment of chlorobenzene with methyl 2-phenyldiazoacetate produced a regio-isomeric mixture of 7-carbomethoxy-2-chloro-7-phenylnorcaradiene/7-carbomethoxy-2-chloro-7-phenylcycloheptatriene, 3a/3′a, and 7-carbomethoxy-3-chloro-7-phenylnorcaradiene/7-carbomethoxy-3-chloro-7-phenylcycloheptatriene, 4a/4′a. When p-methylanisole was treated with methyl 2-phenyldiazoacetate at 80°C, a product that largely favored a fused cyclopropane structure, 7-carbomethoxy-2-methoxy-5-methyl-7-phenylnorcaradiene, 12a, was obtained along with the benzylic C–H insertion product methyl 3-(p-methoxyphenyl)-2-phenylpropionate, 13a. Heating the norcaradiene product 12a at 110°C yielded the ring-opened diarylacetate, 14a. The diene forms of the fluxional norcaradiene-cycloheptatriene systems were trapped with benzyne to give one stereoisomer of 3,3-disubstituted benzhomobarralenes, 18a–d. The norcaradiene-cycloheptatriene valence isomers were quantitatively converted into ring-opened diaryl acetate products upon acidification in acetonitrile. Rates for the addition of methyl (p-chlorophenyl)diazoacetate to benzene were first order with respect to the diazo reagent. A concerted mechanism involing an iron carbene complex is proposed for these iron porphyrin-catalyzed Büchner reactions.
Adsorption Kinetics and Isotherms of Methylene Blue by Geopolymers Derived from Common Clay and Rice Husk Ash
(Scientific & Academic Publishing., 2017) Maingi, F.M.; Mbuvi, H.M.; Ng’ang’a, M.M.; Mwangi, H.
With the onset of industrialization mankind has witnessed various environmental issues in the society. Industrialization has not only brought development and prosperity but eventually disturbed the ecosystem. It is currently estimated that 1.1 billion people in the world lack access to enhanced clean water supplies. Consequently, pursuance of sustainable materials and technologies for wastewater remediation is critical. Use of adsorbents for wastewater treatment is preferable due to their simplicity and cheap materials involved. Geopolymers are synthesized hydrothermally using alumina and silica which possesses amorphous surface for use as adsorbents. There is adequate information and reports in literature that indicate clay contain alumina and silica. Similarly, findings have shown that rice husk ash contains substantial amounts of silica. This work reports synthesis of geopolymers GP-1, GP-2 and GP-3 prepared by using different SiO2/Al2O3 ratios and consequently equilibrium and kinetics behaviour of adsorption of methylene blue. The geopolymers were characterized using FT-IR, EDS, XRD and SEM. Geopolymer adsorbents were subjected to methylene blue batch sorption experiments that indicated the adsorption of MB increased with increased Si/Al ratio in geopolymers. The adsorption isotherms were described by Langmuir, Freundlich, Temkin and Sips isotherms. Data for adsorption of MB onto geopolymers fitted best in Sips adsorption model. Kinetic studies showed that Pseudo -second order model were more suitable than the Pseudo- first order model in explaining the kinetics of adsorption.
Adsorption kinetics and isotherms of methylene blue by geopolymers derived from common clay and rice husk ash
(Scientific & Academic Publishing, 2017) Maingi, F. M.; Mbuvi, H. M.; Ng’ang’a, M. M.; Mwangi, H.
With the onset of industrialization mankind has witnessed various environmental issues in the society. Industrialization has not only brought development and prosperity but eventually disturbed the ecosystem. It is currently estimated that 1.1 billion people in the world lack access to enhanced clean water supplies. Consequently, pursuance of sustainable materials and technologies for wastewater remediation is critical. Use of adsorbents for wastewater treatment is preferable due to their simplicity and cheap materials involved. Geopolymers are synthesized hydrothermally using alumina and silica which possesses amorphous surface for use as adsorbents. There is adequate information and reports in literature that indicate clay contain alumina and silica. Similarly, findings have shown that rice husk ash contains substantial amounts of silica. This work reports synthesis of geopolymers GP-1, GP-2 and GP-3 prepared by using different SiO2/Al2O3 ratios and consequently equilibrium and kinetics behaviour of adsorption of methylene blue. The geopolymers were characterized using FT-IR, EDS, XRD and SEM. Geopolymer adsorbents were subjected to methylene blue batch sorption experiments that indicated the adsorption of MB increased with increased Si/Al ratio in geopolymers. The adsorption isotherms were described by Langmuir, Freundlich, Temkin and Sips isotherms. Data for adsorption of MB onto geopolymers fitted best in Sips adsorption model. Kinetic studies showed that Pseudo -second order model were more suitable than the Pseudo- first order model in explaining the kinetics of adsorption
Adsorption of Lead (ii), Chromium (vi) and Manganese (ii) metal ions from water using modified Pennisetum purpureum Schumach plant stalk
(2022) Murage, D.; Masika, E.; Wanyonyi, W. A.
Water pollution is a global problem affecting humanity. Availability of clean water is a fundamental prerequisite to public health safety and the survival of the human race as well as animals. However, pollution of river water by heavy metal ions deposition is a grave environmental problem. Presence of the heavy metals in the water, pose a serious health risk particularly to rural populations which rely majorly on the river water for domestic purposes. Several methods for elimination of the heavy metal pollutants from river waters have been previously employed. However, most of these methods are expensive and cumbersome, hence not sustainable. This research explored the potential of modified Pennisetum purpureum Schumach plant adsorbent in removal of Lead (II), Manganese (II) and Chromium (VI) ions from spiked water samples by adsorption. Surface analysis of the adsorbent using FTIR Photometer confirmed presence of functional groups such as -NH2, C=O and O-H responsible for adsorption of heavy metal ions. Concentration of heavy metal ions in water samples was determined before and after adsorption process using Atomic Absorption Spectroscopy (AAS) and means concentration computed. Effect of changes in pH on adsorption was investigated by conducting adsorption at three different pH conditions of 5, 7 and 9. Modification of the adsorbent surface improved its adsorption capacity. For instance, at pH 5, adsorption of Cr+6 increased from 12% to 14.82% when modified adsorbent was used. The modified adsorbent achieved greater % adsorption in all the three metals. Increase in the pH of adsorption from 5 to 9 had a reducing effect on the percent adsorption. At pH of 5 the % adsorption of Pb+2 reduced from 90.26% to 73.75% at pH of 9. This reductions in percentage adsorption were recorded for Pb+2 and Mn+2 ions but not significant for Cr+6 ions. These results show the potential of P. purpureum plant for use as an adsorbent in purification/detoxification of river water which would present a cheaper and more readily available alternative to many current adsorbents and adsorption methods in use. However further research is needed to determine the optimal set of conditions as well as the most suitable modification treatment for maximum adsorption
Adulticidal activity and Toxicity of Extractives from Teclea Trichocarpa against Adult Maize Weevil (Sitophilus Zeamais)
(Annals. Food Science and Technology Volume 13, Issue 2, 2012, 2012) Chhabra, S. C.; Mwangi, E.S.K.; Keriko, J. M.; Machocho, Alex K.
With a growing world population and increased affluence leading to demand for more and higher quality foods, and given environmental problems such as soil degradation, water scarcity, and biodiversity loss, new and innovative solutions are required to minimize food losses caused by pests. Organic solvent extracts and thereof isolated compounds of Teclea trichocarpa Eng. were evaluated for adulticidal activity against maize weevil, Sitophilus zeamais Motchulsky, and for brine shrimp, Artemia salina, lethality. Hexane extract of the leaves of T. trichocarpa displayed mild brine shrimp toxicity (LD50=153.2 μg/ml), while the other extracts showed no significant toxicity (LD50>240 μg/ml). Both hexane and dichloromethane extracts of leaves of T. trichocarpa showed dose dependent meanpercentage adulticidal activity. At 600 and 800 ppm these extracts, respectively, were comparable to the positive control, actellic super, a synthetic pesticide which is in the market today. Considering the cost, increasing incidence of pesticide resistance and environmental concerns posed by synthetic pesticides,several pressures have accelerated the search for more environmentally and toxicologically safe, moreselective and efficacious pesticides. Results discussed with regard to the use of the plant extractives as suitable andsustainable alternative to synthetic insecticide in maize grain storage and could be incorporated in integrated pest management. Keywords:brine shrimp; Teclea trichocarpa; adulticidal activity; maize weevil, Sitophilus zeamais
Advances in Green Nanotechnology: Data for Green Synthesis and Characterization of Iron Nanoparticles Synthesized Using Galinsoga Parviflora, Conyza Bonariensis and Bidens Pilosa Leaf Extracts, and their Application in Degradation of Methylene Blue Dye and Rifampicin Antibiotic
(Elsevier, 2023) Wanakai, Sammy Indire; Karerua, Patrick Gachoki; Makhanub, David Sujee; Madivoli, Edwin Shigwenya
This data article reports contents of the information derived from an efficient, environmentally friendly, and lowcost method of synthesis and recovery of iron nanoparticles using Galinsoga parviflora, Conyza bonariensis and Bidens pilosa aqueous leaf extracts as reducing, stabilizing, and capping agents, and applications of the nanoparticles in degradation of organic dyes and antibiotics. Various spectroscopic and microscopic techniques were used to collect the data. Data is displayed in the form of .raw files, graphs, images, Microsoft Excel sheets, .data point files, and PDF files, along with other formats. Data analysis and interpretation methods have also been presented. Researchers, research students, academicians, and industrialists can benefit greatly from the data in order to gain knowledge about the green synthesis of iron nanoparticles and related applications such as degradation organic pollutants. The data is deposited in the mendeley data repository as two independent datasets at https://data.mendeley.com/datasets/rxkv6j7hrx.
Alkaloids from Ammocharis tinneana
(Phytochemistry, 1999) Machocho, Alex K.; Chhabra, S. C.; Viladomat, F.; Codina, C.; Bastida, J.
Sixteen alkaloids have been isolated from fresh bulbs of Ammocharis tinneana (Amaryllidaceae), seven of which contain a 1,2β-epoxide group. 6α-Hydroxycrinamidine and 6α-hydroxyundulatine are reported here for the first time from a natural source. The structures and stereochemistry of these new alkaloids have been determined by physical and spectroscopic methods. 1H and 13C NMR spectra of flexinine, 1,2β-epoxyambelline and 11-O-acetyl-1,2β-epoxyambelline were completely assigned by means of 2D NMR techniques.
Alum treated grey water for toilet flushing, mopping and laundry work
(2012-03-20) Skudi, Joseph B.; Wanjau, R. N.; Murungi, Jane; Onindo, Charles O.
The paper presents the study carried out in a peri urban settlement of Nairobi Kenya and involved treatment of raw grey water generated from bathroom, kitchen and laundry for flushing toilet and laundry work. The study utilized both chemical and physical treatment. The chemical treatment involved alum addition in the raw grey water and pH adjustment using bicarbonate salts. The physical treatment involved filtration using Quartz sand and filtration of pH adjusted treated grey water using filter paper. The major ions studied were ions which could interfere with lathering of soaps or could cause stains on clothes and toilet fixtures or could be potentially health hazardous. These ions were Fe, Mn, Ca, Mg, Pb and Hg. The levels of these ions in raw grey water and in treated grey water were determined using atomic absorption spectroscopy. The results for the levels of these ions before treatment were compared to the set standards for potable water by Kenya Bureau of Standards [1]. The levels of these ions in the treated grey water after adjusting the pH were found to be within the Maximum Contaminant Limits (MCL) set by KEBS [1]. Thus the overall treatment of the raw grey water produced water of good quality which complied with the set standards for potable water by KEBS [1]. The results of this treatment could contribute immensely in the fulfillment of the millennium development goals.
Ameliorating Sisal Leaf Wastes in Purveying Plant Macronutrients
(International Journal of Research and Analytical Reviews (IJRAR), 2020) Echessa, A.C. Peter; Nyambaka, Hudson; Changamu, Evans
Sisal (Agave sisalana) is extensively grown in Kenya. It is a high waste generating crop. Waste disposal has remained a challenge to the sisal processing set ups. The wastes are used as landfills and or are burned to ashes despite being rich in plant macronutrients. Direct use scorches crops due to high acidity. Though composting takes too long before the biomass can be in use, it remains the recognizable approach, The study sought to establish pH trends of decomposing pretreated SLW with a view of seeking approaches to shorten the otherwise long period. Sisal leaf wastes (SLW) from young, mid old and old leaves were soaked in distilled water fresh, sun or shade dried and corresponding pH monitored. Effects of boiling SLW in lye and sodium hydroxide on deterioration were compared. It was established that natural decomposition of SLW is accompanied with a pH change from ≤ 4.8 (acidic) to > 7.5 (basic). SLW from young sisal leaves as well as shade dried ones deteriorated faster compared to those soaked fresh or after sun drying. Those (SLW) boiled in lye had evolution of the biogas earlier than either the fresh or 2M NaOH treated (boiled) samples. The SLW soaked without pretreatment on average took the longest period before biogas was detected. It is apparent from this study that boiling the SLW in an alkali shortens the decomposition period hence enables an easy access to macronutrient. Utilization of SLW in enhancing crop production would be an economical pathway of their disposal.
Analysis Levels of Boron in Three Varieties of Watermelons from Githurai and Mwea Markets in Kenya
(2013-01) Wanjau, R. N.; Nthiga, E.W.; Murungi, J.I.
The paper represents a study carried on concentration of silicon in parts of three varieties of watermelons namely the Charleston grey (sugar Fl), Crimson sweet (Zebra) and the Sugar baby. Watermelons were obtained from Githurai and Mwea markets in Kenya from different vendors for a period of 12 months. AAS instrument technique was used for qualitative and quantitative analysis of silicon in different parts of a watermelon. A one way ANOVA and the student t-test were used to determine the variation in levels of silicon: different parts and varieties of watermelon and variation between the levels of silicon in the two markets respectively. The mean levels obtained iJ1 this study in the four parts of the three varieties were O- .66±O.04~-0.,8'1-±--O-.-0+6---m""g-/-g'=S-i-.
Analysis of Deltamethrin Residue Amounts Using HPLC in Some Vegetables Consumed in a Rural Area - Makuyu, Kenya
(Globeedu Group, 2014) Kithure, Joyce G.N.; Murungi, Jane I.; Wanjau, Ruth N.; Thoruwa, Caroline L.
Vegetables are brimming with fibre, plus a whole range of vitamins and minerals, and because they are low in calories, they make an important and healthy addition to any diet. Scientific studies have shown that people who eat a lot of vegetables may have a lower risk of getting illnesses, such as heart disease and some cancers. For this reason, health authorities recommend that you eat at least five portions of fruit and vegetables every day. Pests, diseases, and weeds destroy vegetables reducing their yield and causing blemish thus making them unfit for sale and consumption. Pesticides maintain the high levels of vegetable production in Kenya. There are many pesticides in use today including; insecticides, acaricides, nematocides, herbicides, and avicides. Pyrethroids are the most commonly used insecticides. The pyrethroids in use include; deltamethrin, lambda-cyhalothrin and chismethrin. However, although vegetables are widely consumed by almost everybody in Kenya, there is little work reported on the analysis of pesticides residues in vegetables. Most of the vegetables are grown in the rural areas, with most farmers growing them on small-scale and hence these vegetables never the reach cities. In this study deltamethrin was analysed in selected vegetables which include; kales, cabbages and tomatoes grown I rural area during the dry and wet seasons. The vegetables were bought from different sellers in Makuyu market. They were then homogenized to give analytical samples. Deltamethrin residues were extracted from the samples using organic solvents. The residues were then determined using high performance liquid chromatography (HPLC). Analyses of data was done using ANOVA, t-test and regression analysis. The deltamethrin mean residue levels ranged between 0.0800±0.1300 and 0.1400±0.0800 mg/kg during the dry season and between 0.00120.0016 and 0.1100±0.0080 mg/kg during the wet season. The study showed that deltamethrin mean residue levels were higher during the dry than during the wet season in the vegetables analysed. The differences were not statistically different for most of them. During the dry season the deltamethrin mean residue levels in the vegetable samples were all higher than the Acceptable Daily Intake (ADI) of 0.02 mg/kg, but they were all lower than the Maximum Residue Levels (MRLs) of 0.2 mg/kg. During the wet season the deltamethrin mean residue levels were lower than the ADI except in kale samples. During the same wet season the deltamethrin mean residue levels were all lower than the MRLs.
Analysis of Essential Oil from Kenyan Eucalyptus Globulus Labill.
(Faculty of Science Kenyatta University, 1998) Akeng'a, T. A. R.; Chhabra, S. C.
The essential oil of fresh leaves of Eucalyptus globulus Labill. (Myrtaceae) obtained from Muguga Arboretum, Kiambu District, Kenya, was extracted by steam distillation for varying times and analysed using GC and GC-MS. The optimum time was found to be 5 hours with the yield of the oil being 2.48% while the content of 1,8-cineole was found to be 55.87%. Other constituents in this medical oil include eudesmol, (±)-linalool, B-pinene,trans-citral, carvone and a-terpineol
Analysis of genetic structure of Melia volkensii (Gurke.) populations using random amplified polymorphic DNA.
(African Journal of Biotechnology, 2004) Runo, M.S.; Muluvi, G. M.; Odee, David W.
Melia volkensii (Gurke.) is a popular fast growing agroforestry tree species in the East Africa’s arid and semi arid lands (ASALs). The species is valued for its high quality termite resistant timber. In addition, its fruits are eaten by livestock thus making it the species of choice by small-scale farmers. However, the species has been overexploited and information on its existing gene pool is currently lacking. The present work was therefore carried out using random amplified polymorphic DNA (RAPD) markers to assess genetic diversity within and between populations in order to suggest appropriate conservation and management strategies. Eight RAPD primers generated 38 scorable polymorphic bands which were used to estimate genetic distances between populations and for construction of neighbour-joining phenograms. Analysis of Molecular Variance (AMOVA) indicated significant genetic differentiation between populations in the eastern and the coastal regions with 21.1%, (P < 0.0002) of the total variation attributed to differences between these regions. There was a clear split between populations from Eastern and Coastal populations of Kenya. These differences may be due to ecogeographical association with genetic variation and should be conserved to retain the full breadth of genetic variation of the species. Key words: Melia volkensii, random amplified polymorphic DNA, genetic variation, agroforestry species.
Analysis of Physico-Chemical Parameters and Selected Heavy Metals in Aquatic Ecosystems.
(IOSR-JAC, 2023-09) MunenePaul M.; Mbugua, Gerald W.; Wanjau, Ruth N.; Ndiritu, N. James
The quality of aquatic ecosystems is of great concern. Elevation of pollutants in water could cause health disorders in human and destabilize the aquatic ecosystem. The case study investigated quality of water from five sites of Lake Turkana selected based on proximity to potential anthropogenic pollution sources. Temperature, pH, electrical conductivity (EC), dissolved oxygen (DO), salinity, total dissolved solids (TDS) and OxidationReduction Potential (ORP) were measured at the site using YSI Pro 1030 Multiparameter electrode while nitrates and phosphates were determined at Kenyatta University’s food science laboratory using Vis 130 Spectrophotometer. Selected heavy metals (lead, cadmium and chromium) were determined using flame atomic absorption spectroscopy. Sampling was performed in triplicates during the dry season. The results were: temperature (28.24±0.96 to 28.86±0.38°C), pH (9.04±0.21 to 9.46±0.06), electrical conductivity (281.57±0.41 to 289.46±3.95 Ωcm-1 ), dissolved oxygen (6.3±0.79 to 7.04±0.05 mg/L), salinity (1.67±0.00 to 1.70±0.01 ppt), TDS (2093.4±0.39 to 2135.8±4.86 mg/L), ORP (-54.22±0.12 to 588.14±0.51 mV), nitrates (5.52±0.31 to 10.04±1.82 mg/L) and phosphates (0.47±0.06 to 0.72±0.15 mg/L). Water lead (0.11±0.01 to 0.12±0.00 mg/L), cadmium (0.00±0.00 to 0.03±0.00 mg/L) and chromium (0.01±0.00 to 0.03±0.01 mg/L). The results showed that pH and TDS were beyond WHO standard of 6.5-8.5 and 600.0 mg/L respectively while phosphates exceeded USEPA limit of 0.024 mg/L in all sites. The electrical conductivity and nitrates complied with WHO standards of 400.0 Ωcm-1 and 50.0 mg/L respectively while the other parameters were not guided by WHO. The lead levels in water exceeded WHO standard of 0.01 mg/L in all sites. The cadmium levels in Impressa and Long’ech beaches in the upstream section exceeded WHO standard of 0.003 mg/L. However, chromium complied with WHO standard of 0.05 mg/L in all sites. These calls for measures keep all the parameters under surveillance to ensure water quality is maintained.
Analysis of the levels of arsenic in home-made brews, spirits, in water and raw materials using Hgaas in Nairobi county
(Academic Journals, 2013-08) Onindo, Charles O.; Murungi, Jane; Wanjau, R.; Masime, Jeremiah O.
This study was carried out to determine the levels of arsenic in the home-made brews, home-made spirits, raw materials and water. One hundred and thirty two home - made alcoholic beverages, one hundred and ten water and eighteen raw materials samples obtained from various parts of Nairobi slums and its environs were analyzed for arsenic. The method of analysis was hydride generation atomic absorption spectroscopy. All home-made brews samples contained concentrations of arsenic that were lower than the standard for total arsenic allowed in water. The concentrations of arsenic in both brew and water ranged from ND to 0.88 ± 0.028 mg/L. These concentrations in these homemade brews and raw materials used varied depending on the brew. The recommended maximum contamination levels set by Kenya Bureau of Standards (KEBS) and WHO for arsenic in alcohols is 0.05 mg/L. Values of arsenic obtained in the drinks and the raw materials used were generally low. This also implies that the tap water and home-made brews are safe. In general, those consuming home-made brews are the young and elderly living in the slum areas in Nairobi County and it is these populations that is more vulnerable to over exposure of this metal. It is recommended that foods and drinks be tested for arsenic regularly to determine whether they meet the EPA/WHO standards.
Analysis of the levels of arsenic, Nitrate, Nitrite and Phosphate in home made brews, spirits, tap water and in raw materials in Nairobi County
(2012-03) Masime, Jeremiah Odhek
Alcohol and water may be an important source of exposure to arsenic, nitrate, nitrite and phosphate. Increased cases of deaths as a result of consuming home made brews/spirits have been a major concern in this country. Recently, many lives have been lost due to the ignoranceof the brewers and their patrons. Additives like methanol and use of untreated river waters that contain the effluents from chemical industries, domestic wastes from urban settlements and run-offs from agricultural activities can cause high levels of arsenic, nitrate and phosphorus in alcoholic drinks, which could be sources of health hazards to consumers since they are toxic. Arsenic, nitrate and nitrite are carcinogenic; phosphate does not have any notable health effects. Nitrite also causes metheglobinemia. Therefore, this study was carried out to determine the levels of these substances in home- made brews, home made spirits, raw materials and water. One hundred and thirty two (132) homemade alcoholic beverages, fourty eight (48) water and twelve (12) raw materials samples obtained from various parts of Nairobi slums and its environs were analyzed for arsenic, nitrate, and nitrite and phosphate. Methods of analysis included; colorimetry, hydride generation atomic absorption spectroscopy and UV -visible spectrophotometry. Some samples of brews and water had higher levels than those recommended by the Kenya Bureau of Standards (KEBS) and World Health Organization (WHO). Concentrations of arsenic ranged from non detectable to 0.88 ± 0.028 mg/l, nitrate from non detectable to 46.3 ± 1.404 mg/l, nitrite from non detectable to 11.919 ± 0.36 mg/l and phosphorous from 0.14 ± 0.008 to 4.16 ± 0.62 mg/I. The recommended maximum contamination levels set by KEBS/WHO for arsenic, nitrate, nitrite and phosphorus in water were as follows; arsenic, 0.01 mg/l for drinking water and beer and raw materials; nitrite, 0.03 mg/l; nitrate 50 mg/l and 2.2 mg/l for the phosphates in water. Most of the home made brews/spirits and water analyzed in this study had lower levels of nitrates than recommended by the Kenya Bureau of Standards, while a few had higher levels of nitrites. Arsenic recorded values lower than the maximum contamination limit of 0.01 mg/I. Nitrate levels were higher than the maximum contamination levels in some cases. Brews had low levels of nitrate, phosphorus and arsenic had low levels of the nutrients. Raw materials also had high levels of these nutrients while water had non detectable levels. The raw materials used may have contributed in elevating the levels of these pollutants in the brews. These findings are therefore useful since they provide a justified cause for the Kenyan Government to reconsider fighting the selling of local alcoholic beverages. Therefore the consumption of the brews with higher levels than those recommended could pose a problem for

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