Open Access Original Research Article

Validation of UV - VIS Spectrophotometry for Phosphorous Molybdenum Determination in Soils of Vietnam

Khuyen Thi Kim Vo, Lan Thi Thuy Bui, Gregory Elayeche Oko, Emmanuel Paul Okoi, Sowale Omowumi Ayomide

Chemical Science International Journal, Page 1-15
DOI: 10.9734/CSJI/2018/42128

Phosphorus existing under different forms and status in soils is a significantly important nutrient during the growth and development of trees. Spectrophotometry has been developed with many types of reagents to determine phosphorus in environmental samples. Molybdenum blue reaction with ascorbic acid as a reducing agent and antimony tartrate catalyst in strong acid environment gave maximum absorbance wavelength at 890 nm. Under the optimised conditions, this method gave very high recovery efficiency, accuracy and sensitivity (up to 0.06 mgP/L) in determination of total phosphorus (around 90%) and bio-available phosphorus (nearly 96%) in soils in Vietnam. The formed blue phosphomolybdenum complex was oxidized by the addition of hexavalent chromium and nitrite ions, leading to the decrease in intensity of blue color, negative error of 10% at 5 mg/L NO2- and 3 mg/L Cr6+, which was in contrast to the positive effect of silicate ions at high amount of over 5 mg/L SiO32-. -squared standard combined with two-way ANOVA analysis highlight the relationship between concentration, time and intensity signals, thus validating the molybdenum blue method before application in phosphorus determination for soil assessment. Olsen and Oniani extraction gave high recovery efficiency despite differences in quantified concentration of bio-available phosphorus. Although the studied soils low amount of total phosphorus (around 0.03 %P2O5), they were medium to rich in bio-available phosphorus with the level of 8 to 15 mg P2O5 / 100 g soil. 

Open Access Original Research Article

Background Correction Method for Determination of Ascorbic Acid in Baobab Fruit Pulp Using Direct UV Spectrophotometry

Ibrahim Yaagoub Erwa, Mahgoub Ibrahim Shinger, Omer Adam Omer Ishag

Chemical Science International Journal, Page 1-6
DOI: 10.9734/CSJI/2018/41080

Herein a background correction method has been utilized for the estimation of ascorbic acid in baobab (Adansonia digitata L.) fruit pulp using direct UV spectrophotometry. The background correction based on catalytic oxidation of the acid by copper (II). EDTA was used to correct the absorption due to copper (II). The absorbance and remained essentially constant at 267 nm at pH range from 6 to 8, with highest absorption at pH 6. The calibration graph was linear up to 20 μg ml-1 of ascorbic acid, correlation coefficient (r = 0.9998) and the molar absorptivity was 1.52 × 104 l mol-1 cm-1. The mean value of ascorbic acid was 237 ± 18 mg/100 g using the proposed method and 250 ± 15 mg/100 g using indophenol official method. The statistical analysis of data revealed no significant difference in precision of the two methods and there is no evidence that the two sets of results are significantly different at 95% confidence interval. The proposed method is selective, accurate and acceptable for determination of ascorbic acid in baobab fruit pulp.

Open Access Original Research Article

Effect of Turbidity and Contact Time on the Rate of Biosorption of Ni2+, Pb2+, Cr3+ and Cu2+ from Wastewater Using Moringa oleifera

Chavaregi Geoffrey, J. L. Kituyi, S. Lutta

Chemical Science International Journal, Page 1-7
DOI: 10.9734/CSJI/2018/39672

Heavy metals in water have been a major preoccupation for researchers for many years due to their toxicity towards aquatic life, human beings and the environment. As they do not degrade biologically like organic pollutants, their presence in industrial effluents and drinking water is a public health problem. Consequently, there is need to come up with novel methods of heavy metals remediation which are more effective and reliable. The biosorption processes using biosorbents like Moringa oleifera have been found to be affected by various physical and chemical factors. Therefore, the present study sought to determine the effect of turbidity and contact time on the rate of biosorption of Ni2+, Pb2+, Cr2+ and Cu2+ from wastewater using Moringa oleifera. Atomic absorption spectrometer (AAS) was used to analyse samples for levels of massive metal species; Pb2+, Cr3+, Cu2+ and Ni2+ before and after treatment with oleifera biosorbent. The effect of turbidity and contact time on the biosorption of the heavy metals by the Moringa oleifera biosorbent was studied by varying these parameters.  Results obtained in the study showed that percentage adsorption decreased from 99, 96, 95 and 87% in 20 ml of turbid solution to 70, 92, 93 and 60% in 50 ml cloudy solution for Pb2+, Cr3+, Cu2+ and Ni2+ respectively. Sixty minutes of equilibration time was found to be adequate for adsorption of the considered metal ions. Several kinetic models were applied to the adsorption data, and it was found that pseudo-second order fitted well with the adsorption data.  It was therefore concluded that M. oleifera could be used as a low-cost adsorbent for the removal of heavy metals from aqueous solutions.

Open Access Original Research Article

Bentonite Nanoclay Assisted Hydrophilic Nylon Fabrics

Sujani B. Y. Abeywardena, Srimala Perera, K. M. Nalin de Silva, S. Walpalage, M. C. W. Somaratne

Chemical Science International Journal, Page 1-6
DOI: 10.9734/CSJI/2018/41670

Aim: Biomimetic surface modifications have gained significant attention in fabric innovations. In this study, elephant mud bathing was mimicked to create a superior hydrophilic nylon fabric.

Place and Duration of Study: Sri Lanka Institute of Nanotechnology and The University of Moratuwa, Sri Lanka, June 2017- March 2018.

Methodology: Bentonite nanoclay (BNC) grafted on nylon using silane as a coupling agent. Fourier transform infrared spectrophotometry, electron microscopy, energy dispersive X-ray spectroscopy and thermogravimetric analysis confirmed the successful grafting of nanoclay on nylon while textile protocols proved the wettability.                                                               

Results: Infrared spectroscopy and elemental analysis confirmed the presence of organic chains and Si groups in bentonite nanoclay modified nylon fabrics. The accomplishment of the surface modification was quantitatively proved by thermogravimetric analysis. SEM images clearly show a thin layer of clay on nylon fibres after being treated with bentonite nanoclay. BNC coated nylon show superior wettability and dryability.                                             

Conclusion: It is expected that this bio-inspired wettable nylon fabric may break the barrier of using nylon in various hydrophilic textile applications.

Open Access Original Research Article

Evaluation of Synergistic Effect of Different Compositions of Liquid Extract of Citrus limonium and Its Linkage with β-cyclodextrin for the One-pot Multicomponent Synthesis of Pharmacological Bioactive Compounds with Application of Exploratory Analysis

Deepali Agarwal, Jyotsna Dhanik, Ankita Verma, Virendra Kumar Kasana

Chemical Science International Journal, Page 1-13
DOI: 10.9734/CSJI/2018/42134

The ability of liquid extract of Citrus limonium and Citrus limonium-β-cyclodextrin composite to promote multicomponent reactions of pharmacologically bioactive compounds from a diversity of aromatic aldehydes has been described. Development of Citrus limonium-β-cyclodextrin composite was characterized using scanning electron microscopy (SEM) and X-ray diffraction pattern (XRD). Liquid extract of Citrus limonium efficiently catalyzed one pot two and three component reaction of α-aminophosphonates, 1H-benzo[d]imidazoles and 9,10-dihydrobenzo[a]xanthen-11(12H)-ones, whereas, Citrus limonium-β-cyclodextrin composite showed a higher catalytic activity for four component reaction of 6-amino-2,4-dihydro-3-methylpyrano[2,3-c]pyrazole-5-carbonitriles and 3,4-dihydro-2H-indazolo[2,1-b]phthalazine-1,6,11(13H)-triones. The method is superior to the existing methods as catalysts provide less reaction time, easier workup and afford good to excellent yields under solvent-free condition. Application of principal component analysis and variable correlation analysis extract the information and further evaluate the catalytic efficiency of liquid extract of Citrus limonium and Citrus limonium-β-cyclodextrin composite. Also, PCA applied on catalytic activity of different constituents of liquid extract of Citrus limonium and their different ratios gave the idea of their synergistic effect for the synthesis of above pharmacological compounds.