Open Access Short Research Article

Development and Validation of HPTLC-Densitometric Method Compared to Titrimetric Method for Determination of L-ascorbic Acid in Citrus Fruits

Chodaton Zinsou Marthe Dominique, Houngbeme Gouton Alban, Ganfon Habib, Ableto Mathias, Gbenou Joachim Djimon, Gbaguidi Fernand

Asian Journal of Chemical Sciences, Page 40-48
DOI: 10.9734/ajocs/2021/v10i319096

Aims: The aim of this study is to develop and validate an efficient method for the specific determination of L-ascorbic acid in citrus fruits and to compare it with a usual method, method using 2,6-dichlorophenolindophenol

Methodology: The research for a specific method for determination of L-ascorbic acid has led to development and validation of High Performance Thin Layer Chromatography – Densitometric (HPTLC-D) method. The validation criteria evaluated are response function, determination reading wavelength, limit of detection, precision of the technique, limit of quantification and recovery rate. The validated method was applied to citrus juice samples for quantification of L-ascorbic acid. Then a 2,6-dichlorophenolindophenol titrimetric assay of L-ascorbic acid in the same sample was performed for comparison of method results.

Results: HPTLC-D method showed improved sensitivity on 360 ​​nm scanner and a good linearity relationship between standard concentrations and absorbance responses. The regression coefficient obtained is R2 = 0.99. The limit of detection (LOD) and the limit of quantification (LOQ) are respectively 3 ng and 9.5 ng per deposit. The method also exhibited good repeatability and precision, with intra-day (n = 3) and inter-day (n = 4) coefficients of variation (CV) of less than 6%.

Application of the HPTLC-Dmethod to citrus juices yielded a recovery rate ranging from 97% to 99%.

Conclusion: Comparison of results of the two methods shows that the contents obtained by titrimetry are greater than those obtained by HPTLC-D by 42.25%. This is explained by the presence of other redox compounds which are dosed at the same time as L-ascorbic acid. HPTLC-D makes it possible to specifically dose L-ascorbic acid.

Open Access Original Research Article

Effect of Incorporation of Potash from Ficus carica Fruit Peel Waste into Potash (Nikkih) from Plantain Peel Waste as Emulsifiers on the Physico-Chemical, Functional Properties, and Acceptability of Yellow Achu Soup

Pride Ndasi Ngwasiri, Beng Ikongefuze Ekuh, Noumo Thierry Ngangmou, Dobgima John Fonmboh, Buhnyuy Ngong Christian, Ngwa Martin Ngwabie, Martin Benoit Ngassoum, Ejoh Richard Aba

Asian Journal of Chemical Sciences, Page 1-10
DOI: 10.9734/ajocs/2021/v10i319091

Yellow Achu soup used to eat achu is an emulsion composed primarily of red palm oil and water stabilized by potash as an emulsifier, is regarded as one of the prestigious traditional foods in Cameroon. However, the yellow achu soup faces a problem of stability due to the inability of the potash from plantain peel alone, commonly called Nikkih, to emulsify and stabilize it. This study was therefore aimed at investigating the effect of incorporation of potash from Ficus carica fruit peel to potash from plantain peel, Nikkih, on the emulsification, emulsion stability, and acceptability of yellow achu soup. To this effect, ashes obtained from plantain peels and Ficus carica fruit peel were extracted with water to get their respective crude extracts, potash, with concentrations of 0.07g/ml or 1g/15ml. A mixture experimental design was used to mix different proportions of the plantain peels to Ficus carica fruit peel potash to get 7 samples of the emulsifier, ranging from 100:0, 80:20, 70:30, 60:40, 50:50, 30:70 0:100 denoted as IKM, KIM, MKI, IMK, MIK, KMI, and KKI respectively. The yellow achu soup obtained thereafter was prepared by mixing thoroughly 20ml of partially bleached palm oil, 10ml of emulsifier solution, and 70ml of water at 800C. The pH, emulsification index, foaming capacity, and foam stability of the resulting soup were analyzed followed by an evaluation of its acceptability. The pH of the mixture varied from 11.75 to 11.01, with a pH of 11.53 obtained for the plantain peel crude extract, IMK, and the lowest pH of 11.01 ± 0.01 obtained from the Ficus carica fruit peel ash extract, KKI. The highest alkalinity of 11.75 ± 0.02 for the mixture was obtained at a mixture ratio of 60:40 for sample IMK. The pH of the resulting yellow achu soup decreased as the incorporation ratio increased, with the highest pH of 11.49 using only the plantain crude extract, IKM, to the lowest pH of 10.58 using only the Ficus carica fruit peel ash extract, KKI. The foaming capacity of the yellow achu soup varied from 10.76 ± 2.78% representing the highest for sample IMK while the lowest value was 5.36 ± 0.18% using sample KIM. The foam stability varied from 11.89 ± 2.34% for sample IMK to 4.67 ± 0.79% for sample KIM. Sample MIK displayed the highest emulsifying activity with a value of 65.15±0.30% and 58.79±8.70% after 24 hrs and 48hrs respectively, while KIM had the lowest emulsifying activity of 34.21±0.54% after 24 hours and 34.17±0.23 after 48hours. Out of the ten panelists involved in the sensory evaluation, 50% generally accepted sample MIK, 20% accepted IMK and KMI while 10% preferred MKI. The incorporation of the Ficus carica fruit peel potash to Nikkih serves as a good strategy to improve on the functional properties and acceptability of yellow achu soup.

Open Access Original Research Article

Exploring the Additive Effects of Aluminium and Potassium Sulfates in Enhancing the Charge Cycle of Lead Acid Batteries

Chijioke Elijah Onu, Nnabundo Nwabunwane Musei, Philomena Kanwulia Igbokwe

Asian Journal of Chemical Sciences, Page 11-19
DOI: 10.9734/ajocs/2021/v10i319092

The adoption of aluminium sulfate and potassium sulfate as electrolyte additives were investigated to determine the possibility of enhancing the charge cycle of 2V/ 20AH lead acid battery with reference to the conventional dilute sulfuric acid electrolyte. The duration and efficiency of lead acid batteries have been a challenge for industries over time due to weak electrolyte and insufficient charge cycle leading to sulfation. This has affected the long-term production output in manufacturing companies that depend on lead acid batteries as alternative power source. Hence there is need to explore the use of specific sulfate additives that can possibly address this gap. The electrolyte solutions were in three separate charge and discharge cycles involving dilute sulfuric acid electrolyte, dilute sulfuric acid-aluminium sulfate mixed electrolyte and dilute sulfuric acid-potassium sulfate mixed electrolyte for one hour each. The total voltage after 30 minutes charge cycle was 2.3V, 2.35V and 5.10V for dilute sulfuric acid, aluminium sulfate additive and potassium sulfate additive respectively. The cell efficiency for dilute sulfuric acid, aluminium sulfate additive and potassium sulfate additive electrolytes are 77%, 77% and 33% respectively. The electrolyte sulfate additives were of no positive impact to the conventional dilute sulfuric acid electrolyte of a typical lead acid battery due to the low difference in potentials between the terminals.

Open Access Original Research Article

Characteristics of Effluent from Formic Acid and Sodium Hydroxide Pulping of Kenaf Stem

Jane Adamma Chukwudebelu, Jonah Agunwamba

Asian Journal of Chemical Sciences, Page 20-30
DOI: 10.9734/ajocs/2021/v10i319093

The pulp and paper industry is considered as one of the major potential sources of pollution in the environment and a consumer of wood. Environmental effects have been attributed to chemicals introduced during the manufacturing process. This paper investigated the influence of cooking chemicals, concentration and time on the properties of effluent generated during pulping of agricultural residue. A stem of kenaf which is an agricultural residue was pulped with 20%, 60% and 90% concentrations of formic acid and sodium hydroxide at 1 hour, 2 hours and 3 hours intervals to determine the characteristics of their effluents. The lowest Chemical Oxygen Demand (COD) obtained from formic acid effluent for the 3 hours cooking at 20%, 60% and 90% concentrations was 324mg/l at 60% concentration after cooking for 2 hours while sodium hydroxide effluent has 3050mg/l at 20% concentration after 1hour cooking as its lowest. Formic acid effluent showed lowest Biological Oxygen Demand (BOD) of 10.63mg/l at 60% concentration after cooking for 2 hours while sodium hydroxide has 13.75mg/l at 90% after 1 hour cooking. The value of Total Solid (TS) from formic acid effluent was lowest (16890mg/l) at 60% concentration after cooking for 2 hours while sodium hydroxide lowest value (15524mg/l) was recorded at 20% after 3 hours cooking. Sodium hydroxide effluent has lowest Total Suspended Solid (TSS) of 3165mg/l while formic acid has 2245mg/l both at 90% concentrations after 2 and 3 hours cooking.

Open Access Original Research Article

Polyvinyl Butyral Synthesis Process Based on Deep Eutectic Solvent as a Catalyst

Po Li, Weilan Xue, Zuoxiang Zeng, Li Sun, Yu Bai

Asian Journal of Chemical Sciences, Page 31-39
DOI: 10.9734/ajocs/2021/v10i319095

Polyvinyl butyral (PVB) was prepared by the condensation reaction of polyvinyl alcohol (PVA) with n-butyraldehyde using a catalyst which is a kind of deep eutectic solvent (DES) made of dodecyltrimethylammonium chloride and p-toluenesulfonic acid. The raw materials and products were characterized by Fourier transform infrared spectroscopy (FT-IR). The effects of the following reaction conditions on the degree of PVB acetal, yield and agglomeration of the products were investigated: the mass ratio of n-butyraldehyde to PVA (mBA/mPVA) of 0.48-0.96, the mass ratio of catalyst to PVA (mcat/mPVA) of 0.16-0.64, the low temperature reaction temperature (5-20℃), and the low temperature reaction time (1-3h). The results showed that at mBA/mPVA =0.8, mcat/mPVA =0.32, low temperature reaction temperature of 15°C and low temperature reaction time of 2 hours, the obtained PVB was a homogeneous powder with the highest acetal degree of 73.85%.