Open Access Original Research Article

Heavy Metals Presence in Some Vegetables and Crops Harvested From Farms in Ebocha, Egbeda and Igbo-Etche in Rivers State, Nigeria

I. A. Kalagbor, O. G. Echem, M. L. Omeokwe, H. C. Omelebele, F. Omereji, C. Onwugbuta

Chemical Science International Journal, Page 1-8
DOI: 10.9734/CSJI/2017/33724

Studies of the presence of heavy metals were carried out on some vegetables and crops harvested from farms in Ebocha, Egbeda and Igbo-Etche in Rivers State, Nigeria. These farms are located in communities where oil exploration activities are ongoing. The samples were prepared by wet digestion using a mixture of Perchloric acid (HClO4): Nitric acid (HNO3) in the ratio 1:4 and analyzed using Atomic Absorption Spectroscopy (AAS). The heavy metals concentration in almost all the vegetables and crops studied were high compared to the maximum permissible limits prescribed by World Health Organisation (WHO), Food Agriculture Organization (FAO) and European Union (EU) except Zn. The concentrations of these metals in the vegetables and crops studied are Co (0.10 – 3.88 mgkg-1), Pb (3.34 – 11.27 mgkg-1), Zn (4.21 – 94.34 mgkg-1), Cd (0.03 – 6.97 mgkg-1), Ni (0.10 – 5.70 mgkg-1), Mn (1.65 – 109.86 mgkg-1), Cu (2.15 – 16.11 mgkg-1) and Fe (22.20 – 334.97 mgkg-1). Concentrations of Co are within acceptable limits except in bitter leaf, scent leaf and water leaf from Ebocha (Site 1) farm which were 2.44 mgkg-1, 2.27 mgkg-1 and 3.78 mgkg-1 respectively. Waterleaf from Igbo-Etche farm recorded a concentration of 3.88 mgkg-1. From the results obtained in this study, the tuberous crop (cassava) has higher concentrations of the metals in comparison to the plantain. The order of the levels of heavy metal concentration in the vegetables and crops is presented in the decreasing order of Scent Leaf > Water Leaf > Fluted Pumpkin >Bitter Leaf > Cassava > Plantain. From the four farms, the levels of concentration is Igbo-Etche>Ebocha 1 = Ebocha 2 > Egbeda. Analysis of variance [ANOVA] confirmed significant differences (P<0.05) among the heavy metals present in the vegetables and the crops from these four farms.

Open Access Original Research Article

(±)-CSA Catalyzed Multicomponent Synthesis of Indeno Naphthopyrans and Tetrahydrobenzo[a]xanthen-11-ones Under Ultrasonic Irradiation

Emel Pelit

Chemical Science International Journal, Page 1-8
DOI: 10.9734/CSJI/2017/35380

Aims: This study was designed to synthesis of Naphthopyrans and xanthenes derivatives in green chemistry approach.

Methodology: New 13-aryl-indeno[1,2-b]naphtha[1,2-e]pyran-12(13H)-ones and tetrahydrobenzo[a]xanthen-11-ones were obtained by multi-component reaction of 2-naphthol, aromatic aldehydes, indane-1,3-dione or 5,5-dimethylcyclohexane-1,3-dione in the presence of (±)-camphor-10-sulfonic acid (CSA) catalyst under ultrasonic irradiation.

Results: 13-aryl-indeno[1,2-b]naphtha[1,2-e]pyran-12(13H)-ones and tetrahydrobenzo[a]xanthen-11-ones were obtained in high yields. However, 13-aryl-indeno[1,2-b]naphtha[1,2-e]pyran-12(13H)-one derivatives gave better yields under this conditions.

Conclusion: The desired compounds were obtained in high yields in short reaction times. The advantages of this method are using a powerful nontoxic, inexpensive, eco-friendly, recyclable, easy to handle, and water-soluble organo-catalyst, building several new bonds in one-pot multi-component reaction, low power consumption, short reaction times and high yields.

Open Access Original Research Article

Synthesis and Intrinsic Viscosity-molecular Weight Relationship of Poly(ethylene adipate)

Liwei Chen, Weilan Xue, Zuoxiang Zeng

Chemical Science International Journal, Page 1-9
DOI: 10.9734/CSJI/2017/35258

In this work, two series of poly (ethylene adipate) (PEA) samples with broad and narrow molecular weight distribution (MWD) were prepared by the polymerization between adipic acid and ethylene glycol. An accurate and swift method, one-point method, was used to determine the intrinsic viscosity of PEA samples. On the basis of Mark-Houwink-Sakurada (MHS) equation, the relationship between the intrinsic viscosity and molecular weight was built for PEA (Mw≤11000) in tetrahydrofuran at 298K. The average molecular weights (Mn, Mv, Mw and Mz) were determind by using Gel-Permeation chromatography (GPC). The constants, a and K of MHS equation for the PEA samples dissolved in tetrahydrofuran at 298K were determined by a numerical method, and the influence of polydispersity correction factor (qMHS) on the relationships were studied for PEA with narrow MWD (1.107-1.219) and broad MWD (1.754-1.872).

Open Access Original Research Article

Production of Mucuna pruriens (var. utilis) Proteins Isolates Using Central Composite Design and Effect of Drying Techniques on Some Properties

Kom Blaise, Bernard Clémence, Njintang Yanou Nicolas, Kamga Richard

Chemical Science International Journal, Page 1-12
DOI: 10.9734/CSJI/2017/35376

Response surface methodology was used to model the effect of temperature, NaCl concentration and pH on the production of protein from Mucuna pruriens seeds. The analysis of response surface graphs showed that the optimal parameters correspond to a temperature of 27°C, a concentration of NaCl of 0 mol/L and a pH of 6. The water absorption capacity of the Mucuna protein isolates was 171°g and 124 g of water per 100 g of dry matter respectively for freeze-dried and spray-dried isolates. The granulometric distribution of emulsions was monomodale. The emulsion made with bottom proteins of Mucuna has presented a viscoelastic character.

Open Access Original Research Article

Synthesis of 4,4'-dihydroxyazobenzeneand 4'-Dihydroxyphenylazo-2-naphthol from Diazotised aniline and Anthocyanins from Delonix regia flower

Lawrence Mark Leonard Ogboji, Oaikhena Zekeri Esezobor, Mulu Emmanuel Khan, John Ogbaji Igoli

Chemical Science International Journal, Page 1-5
DOI: 10.9734/CSJI/2017/35020

The synthesis of 4-phenylazo phenol by coupling anthocyanins extracted from Delonix regia flowers with diazotised aniline is presented in this paper. Also reported here is the reduction of 4-phenylazo phenol to yield 4-aminophenol and coupling of 4-aminophenol to phenol and 2-naphthol which yielded 4,4'-dihydroxyazobenzene and 4'-hydroxyphenylazo-2-naphthol, respectively. The structures of the compounds were confirmed by 1H- and 13C-NMR spectroscopy after purification by column chromatography on silica gel.