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Publications


2018

Sila, JM, Guto PM, Michira IN, Mwaura FB.  2018.  Square Wave Voltammetric Determination of Penicillin V in Sodium Dodecyl Sulfate Containing Media on Glassy Carbon Electrode. International Journal of Sciences: Basic and Applied Research (IJSBAR). 40(1):220-233. AbstractInternational Journal of Sciences: Basic and Applied Research (IJSBAR)

Description
The effect of adding sodium dodecyl sulfate (SDS), a surface-active agent to acetate buffer solution containing penicillin V was investigated. The voltammetric responses of penicillin V on glassy carbon electrode was a function of the concentration of penicillin V, surfactant and pH. Addition of SDS to the penicillin V containing acetate buffer solution (ABS) was found to enhance the voltammetric oxidation current signal by about 10 times with insignificant shift of the oxidation potentials. With this electrochemical method, the optimal pH and SDS concentration were found to be pH 4.5 and 0.347 M respectively. Using cyclic voltammetry, the oxidation potential for penicillin V were found to be 1.61 V vs. Ag/AgCl in SDS/ABS, pH 4.5 and 1.55 V vs. Ag/AgCl in ABS, pH 4.5. Linear concentration range were also investigated using square wave voltammetry and found to lie in the range of 0.04–34.6 µM penicillin V in SDS/ABS, pH 4.5 and 3.5–14.0 µM penicillin V in ABS, pH 4.5. Limits of detection were also found to be 0.04 µM penicillin V in SDS/ABS, pH 4.5 and 3.5 µM penicillin V in ABS, pH 4.5 and limits of quantitation were 0.12 µM penicillin V in SDS/ABS, pH 4.5 and 14µM penicillin V in ABS, pH 4.5.

2017

Guto, PM.  2017.  Electrokinetic Behavior of Multiwalled Carbon Nanotubes/Poly‐l‐lysine Modified Electrodes in Sodium Dodecylsulfate Bicontinuous Microemulsions. International Journal of Chemical Kinetics. 49(8):596-601. AbstractInternational Journal of Chemical Kinetics

Description
This work demonstrates for the first time the application of multiwalled carbon nanotubes/poly‐l‐lysine modified pyrolytic graphite electrodes (MWCNTs/PLL/PGE) in sodium dodecylsulfate bicontinuous (SDS BC) microemulsions. Cyclic voltammetric studies of ruthenium(III)hexaamine electroactive probe in these media on both plain and modified pyrolytic graphite electrodes (PGE) mainly gave one peak for each of the cathodic and anodic scans. These reduction–oxidation responses were attributed to [Ru(NH3)6]2+/[Ru(NH3)6]3+ redox couple. In SDS BC microemulsions, the midpoint potentials were found to be −0.22 V for PGE plain and −0.24 V for MWCNTs/PLL/PGE versus saturated calomel electrode. The average peak separations for PGE plain and MWCNTs/PLL/PGE were found to be ∼0.05 and ∼0.04 V between the scan rates of 0.01 and 0.1 V/s, whereas their diffusion coefficients were 1.0 × 10−6 and 7.0 …

2016

Ajwang, BO, Ngugi K, Ogollah K, Orwa G.  2016.  Influence of Financial Prudence on the Performance of the Insurance Industry in Kenya. Journal Of Business Management Science. 2(1) AbstractJournal Of Business Management Science

Description
The measure of performance of insurance companies must not be just on their rate of return on investment but should also include aspects that relates to financial prudence like levels of customer satisfaction, speed of claims settlement and also quality of underwriting services.

Katithi, DN, Michira IN, Guto PM, Baker PPGL, Kamau GN, Iwuoha EI.  2016.  SYNTHESIS AND CHARACTERIZATION OF GREEN TEA SYNTHESIZED IRON NANOCATALYSTS FOR BRYMOTHYMOL BLUE (BTB) DEGRADATION. Journal of Nano Research. 42:1-13.
Oyagi, MO, Onyatta JO, Kamau GN, Guto PM.  2016.  Validation of the Polyacrylic acid/Glassy Carbon Differential Pulse Anodic Stripping Voltammetric Sensor for Simultaneous Analysis of Lead(II), Cadmium(II) and Cobalt(II) ions.. International Journal of Electrochemical Science (IJES). 11:3852-3861.

2015

Oyagi, MO, Onyatta JO, Kamau GN, Guto PM.  2015.  Simultaneous Determination of Trace Lead (II), Cadmium(II) and Cobalt(II) by Differential Pulse Anodic Stripping Voltammetry Using Polyacrylic acid/Glassy Carbon Electrode.. International Journal of Sciences: Basic and Applied Research (IJSBAR). 23(2):324-334.

2014

Oyagi, MO, Michira IN, Guto PM, Baker P, Kamau GN, Iwuha E.  2014.  Polydisperse low Diameter ‘Non-toxic’ Silver Nanoparticles Encapsulated by Rooibos Tea Templates. Nano Hybrids. 8:57-72.
Katithi, DN, Michira IN, Guto PM, Baker P, Kamau GN, Iwuha E.  2014.  Green Synthesis of Iron Nanoparticles on Chamomile in-built Templates. European International Journal of Applied Science and Technology . 1(5):77-98.
Michira, IN, Katithi DN, Guto PM, Kamau GN, Baker P, E. Iwuha E.  2014.  Synthesis, Characterization of Green Tea Stabilized Iron Nanoparticles and their Synergistic Effect on Polyaniline. International Journal of Sciences: Basic and Applied Research. 13(2):63-76.
Kemboi, AK, Mbugua JK, Madadi VO, Guto PM, Kamau GN.  2014.  Adsorption Characteristics of Captafol Pesticide by Sediment and Soil Samples: Apparent Thermodynamic Properties Using Spectroscopic Methods. International Journal of BioChemiPhysics. 22:61-68.

2013

Oyagi, M, Michira I, Guto P, Iwuoha E, Kamau G.  2013.  Synthesis and Characterization of Silver Nanoparticles using tea extracts and their Application in nanobiosensors. International Journal of BioChemiPhysics. 21:30-44.

2012

2011

2010

GUTO, DRPETERSONMOMANYI.  2010.  Peterson M. Guto. Authored "Theory of Spectroscopy. : The University of Nairobi Council

2008

2007

2006

2005

2003

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