International Journal of Engineering & Science ...

IJESR/Jan 2014/ Vol-4/Issue-1/1-5

e-ISSN 2277-2685, p-ISSN 2320-9763

International Journal of Engineering & Science Research

DETERMINATION OF POTASSIUM ION CONCENTRATION IN RED MANGROVE (RHIZOPHORA MANGLE L) BARK AQUEOUS EXTRACT (RMBAE) IN HCl George Daye Mandy.C*1, Okpara Kingsley2, Waribo Helen Anthony2 1

2

Department Pharmacy, Rivers State College of Health Science and Technology, P.M.B 5039 Port Harcourt, Rivers State, Nigeria.

Medical Laboratory Science Department, Rivers State College of Health Science and Harccourt, Rivers State, Nigeria.

Technology, P.M.B 5039 Port

ABSTRACT Studies were carried out on dry ash of red mangrove (Rhizophora mangle L) bark, an agricultural waste, to determine the potassium ion concentration in it, by titratory and spectrophotometric methods. 100gm of the dry ash were dissolved in 1000cm3 and 500cm3 respectively and the aqueous extract from the bark subjected to titration against standard HCl in the concentration ranges of 0.5-2.0M,while AAS was carried out using 2gm of the dry ash in GBC Avanta flame atomic absorption spectrophotometer version 2.02 . The results obtained from the titration reaction revealed that there were high levels of potassium ion concentration (14.7186 to 29.9988gm/dm3 and 18.7200 to 38.000gm/dm3) in both 1000cm3 and 500cm3 solutions. This result was in agreement with the results of AAS result (10,393.16ppm). The percentage purity calculated revealed that the potassium ion obtained from the red mangrove bark aqueous extract (RMBAE) had a purity of 69.94%,showing high purity of the potassium obtained by these methods. The proposed methods were successfully employed to determine potassium ion concentration in red mangrove bark aqueous extract (RMBAE). The methods were very simple, inexpensive, less time consuming and reliable.

Keywords: Potassium ion concentration, Red mangrove bark and Titration 1. INTRODUCTION The red mangrove (Rhizophora mangle L) is one of four mangrove species found in the mangrove ecological community. The other species within this community are White mangrove (Languncularia racemosa), Black mangrove (Avicennia germinaas), and Buttonwood (Conocarpus erectus). Mangrove community plays an important role in tropical and subtropical regions of the world. Different mangrove species protect and stabilizes low lying coastal lands and provide protection and food sources for estuarine and coastal fishing food chains. Its wood is used for fuel, piling, crossties, and charcoal. The bark is seen as an agricultural waste in Nigeria with less attention given to its usefulness. Most recently, researchers have found that aqueous extract from the bark of red mangrove plant has large quantities of tannins (as high as 20-75% dry weight) which prevent damage from herbivores [3,6]. Mangrove extracts have been used for diverse medicinal purposes and have a variety of anti-bacterial, anti-herpetic and anti-Helminthic activities. Again, the extracts of some mangrove species indicated significant anti-oxidant activity due to the presence of condensed tannins compounds in them. Furthermore, condensed tannins from mangrove species Kandelia candel and Red mangrove (Rhizophora mangle L) and their antioxidant activity had been studied. They reported that condensed tannins extracted from two mangrove species showed very good DPPH radical scavenging activity and ferric reducing power, hence, it is a good antioxidant. The pharmacological and toxicological evaluation of red mangrove, as a potential antiulcerogenic drug: Chemical compositions of active extract have been studied [10]. They evaluated the use of this plant in human medicines for the treatment of gastro duodenal ulcers in mice and found that aqueous extracts of red mangrove bark showed gastro protective and anti-Secretory effects without any toxicological effects.

*Corresponding Author

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e-ISSN 2277-2685, p-ISSN 2320-9763

Again, the efficiency of red mangrove bark aqueous extract in the treatment of aphthos ulcers have been reported to reduce the time to repair mucosal tissue and especially mouth mucosa healing [2]. This view was also corroborated [1]. Apart from tannins, researchers have shown that the extract of red mangrove bark aqueous extract contained different elements in varying concentrations. Some of these elements included potassium, sodium, calcium, magnesium, phosphorous and nitrogen [4,7]. The importance of these mineral nutrients to man, soil, plants and chemical industries, can not be overemphasized. Potassium is one of the body’s most important mineral nutrients. Its deficiency, or hypokalemia, causes a variety of problems, such as fatigue, muscle weakness and cramps, bloating, constipation and abdominal pain. Medically, it is classified as an electrolyte, meaning it carries an electrical charge and helps to balance sodium levels in the body, by increasing the amount of sodium excreted in urine, thus reducing high levels in the body. Furthermore, it also plays a key role in Osmo-regulation process of water in plants, where it affects water transport in the xylem, maintain high density cell turgid pressure which affects water tolerance, cell elongation for growth and most importantly regulates the opening and closing of the stomata which affects transpirational cooling and carbon dioxide up take for photosynthesis. Potassium is also needed in our chemical industries in the combined form to produce fertilizers, salts etc. All these sources deplete the normal supply and demand for potassium, hence, the need to find a cheaper, saver and reproductive alternative to getting potassium. Recently, potassium ion concentrations have been isolated and determined in plant tissues especially in mangroves species. But enough studies on red mangrove bark is lacking. Therefore, this study is to determine potassium ion concentration in red mangrove (Rhizophora mangle L) bark aqueous extract (RMBAE).

2. MATERIALS AND METHODS 2.1 Collection and Preparation of Red Mangrove Bark Aqueous Extract (Rmbae) The red mangrove (Rhizophora mangle L) bark was obtained commercially from Timber plank market, mile II Diobu, Port Harcourt, Rivers state, Nigeria during the rainy season. The collected barks were extensively washed with deionized water and air-dried in sun (solar drying) for 120 hours to remove water content in the sample. The dried sample was then converted to finely granulated ash by burning. Two sets of accurately weighed 100gm of the finely granulated burnt ash were dissolved differently in 500cm3 and 1000cm3 of de-ionized water, to bring the elements in the ash into solution, and the solution thoroughly stirred and allowed to homogenize for 48 hours. Afterwards, the solutions were filtered using a quantitative whatman filter paper number 41.The filtrates (red mangrove bark aqueous extract) were taken to determine potassium ion concentration by titrating with standard solution of HCl (0.5-2.0M),and potassium ion concentrations gotten by calculations. The HCl used was of analytical grade. 2.2. Spectrophotometric Method (AAS) In order to check for the presence of potassium ion content in the ash of red mangrove bark, 2.00gm of the dry ash was dissolved in 10 cm3 of aqua reagea (mixture of HCl and HNO3) and was aspirated into the atomic absorption spectrophotometer using GBC avanta flame atomic absorption spectrophotometer version 2.02 and the result obtained is shown in table 2.

3. RESULTS Table 1: Physical parameters of the Red mangrove bark aqueous extract (Rmbae) S. No. 1 2 3

RMBAE Color of solution Touch of solution Test with red litmus paper

Observations Umber Very slippery Turns red litmus paper to blue

Table 2: AAS result of the measured potassium concentration in dry ash of red mangrove bark. Sample Dry ash of red mangrove bark(DARMB) Copyright © 2013 Published by IJESR. All rights reserved

Potassium Concentration (PPM) 10,393.61 2


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Table 3: Results of titration of HCl with 100g/1000cm3 RMBAE Molarity of Acid (M)

Volume of Acid (Vcm3)

Volume of RMBAE (Vcm3)

Molarity of RMBAE (M)

Conc. RMBAE (g/dm3)

Conc. K+ (g/dm3)

% purity both in 1000/500cm3

% of k+

0.5

18.87

25

0.3774

21.1344

14.7186

69.64

37.74

1.0 1.5 2.0

14.57 12.82 5.54

25 25 25

0.5828 0.7692 0.4432

32.6368 43.0752 24.8192

22.7292 29.9988 17.2848

69.64 69.64 69.64

58.28 76.92 44.32

Table 4: Results of titration of HCl with 100g/500cm3 RMBAE Molarity of Acid (M)

Volume of Acid (Vcm3)

Volume of RMBAE (Vcm3)

Molarity of RMB

Conc. RMBAE (g/dm3)

Conc. K+ (g/dm3)

% purity (%)

% of k+

0.5

24

25

0.4800

26.8800

18.7200

69.64

48.00

25

0.7960

44.5760

31.0440

69.64

79.00

25 25

0.9744 0.5448

54.5654 30.5088

38.00 21.2472

69.64 69.64

97.44 54.48

1.0

19.90

1.5 2.0

16.24 6.81

Table 5: Summary of Potassium ion Concentration, Percentages and Percentage Purity in 100g/1000cm3 and 100g/500cm3 respectively Molarity Of Acid (M) 0.5 1.0 1.5 2.0

Volume of RMBAE (Vcm3) 25 25 25 25

Conc. of k+ in RMBAE (100g/1000cm3) 14.7186 22.7292 29.9988 17.2848

Conc. Of k+ in RMBAE (100g/500cm3) 18.7200 31.044 38.00 21.2472

% purity 69.64 69.64 69.64 69.64

% of k+ conc. (100g/1000cm3) 37.74 58.28 76.92 44.32

% of k+ conc. (100g/500cm3) 48.00 79.60 97.44 54.48

Table 6. Results of Titrimetric Analysis of potassium ion Concentration in RMBAE with Statistical Evaluation (n = 4) Dry ash in distilled water (cm3) 100g/1000cm3 100g/500cm3

Mean ± S.D 21.1829 ± 6.76 27.7856± 9.7973

Coefficient of variance 0.3191 0.3526

Coefficient of standard error 3.3800 4.8987

4. DISSCUSSION The results in table 1 were in agreement with the physical properties of a base, thus confirming that the aqueous extract from the bark of red mangrove is a base (KOH). The AAS result confirmed the presence of potassium ion in high quantity or concentration in parts per million (ppm) in the red mangrove bark aqueous extract(RMBAE), which is in agreement with the works done [4,7]. Furthermore, from tables 3 and 4 it was observed that the concentrations of potassium ion increased from 14.7186g/dm3 to 29.9988g/dm3 and 18.72g/dm3 to 38.00g/dm3 in 100g/1000cm3 and 100g/500cm3 respectively, as the concentrations of HCl increased from 0.5M – 1.5M and then reduced.The results also showed that 1.5M HCl concentration gave the highest amount of potassium ion concentration in the acid range studied. It can therefore be inferred that 1.5 M HCl concentrations was the best concentration for the determination of potassium ion from red mangrove bark aqueous extract. The high amount of potassium ion could be attributed to the formation of KCl salt which dissociated completely in solution to form K+ and Cl- spectator ions, thus exposing much of potassium ion in the uncombined form in solution. Copyright © 2013 Published by IJESR. All rights reserved

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Again, the inability of K+ as spectator ion to react with water and other negative ions that might be present in solution could also be implicated. Furthermore, the red mangrove bark aqueous extract contained large amount of tannins (hydrolysable, condensed and combined forms), which are polyphenols [9,10]. According to them, these numerous hydroxyl groups in the molecule of red mangrove bark aqueous extract represented main active sites for binding of ionic compounds. The observed result could be attributed to the ability of tannins (acidified hydroxyl phenols) to bond to other ions in solution in preference to potassium to the moiety, thus exposing more of K+ in solution in the Free State. This can also be explained in terms of chelation between the forms of tannins and bivalent metals such as Ca2+ and Mg2+ found in the red mangrove bark aqueous extract. The mechanism of reaction of tannins in red mangrove bark aqueous extract could be explained and expressed as follows: At low pH (0.5 -2.0M) we have SUR ─ OH + H3O+ → SUR ─ OH2+ +H2O ------------Eq

(1)

Where SUR─ OH denotes the surface of the tannins. These protonated tannins that is positively charged, bonds with anionic compounds like OH present in the solution. In this form SUR ─OH2+ + OH → SUR ─ OH2+OH-- ------------------Eq (2) But with cations, repulsion due to columbic forces of attraction occurs, thus exposing more of K+ in solution as spectator ions. The equation of the repulsion is shown below: SUR ─ OH2+ + K+ → SUR ─OH2+/K+ --------------------Eq (3). Finally, the non-interference of other ions in solution with K+ to masking it and hence reduce the amount that would have been exposed as spectator ions, is another major factor for the high levels of potassium ion in the red mangrove bark aqueous extract. The result in table 5 showed that the percentage purities of potassium ion were constant (69.64) both in 1000cm3 and 500cm3 using 100gm of dry ash of red mangrove bark. The potassium ion from red mangrove bark aqueous extract was high and reasonable. However, the constant value of percentage purity explained that percentage purity from red mangrove bark aqueous extract is not depend on the volume of water used in dissolving it and acid concentration, but rather on the dry mass. Since the dry ash used was of equal weights, there will be no difference in percentage purity. Finally, the results in table 6 showed only a small difference and low values of the coefficients of variance and standard errors; Standard deviation about the mean was also very small. This is a confirmation that the method used was precise and accurate.

5. CONCLUSION The proposed methods were successfully employed to estimate the amount of potassium ion concentration in red mangrove bark aqueous extract. The method was also new, simple, specific, cost effective, reliable, environmentally friendly, accurate and reproducible. Maximal potassium ion concentration was obtained at 1.5M HCl concentration, therefore, 1.5 M HCl is recommended as the best concentration and 500cm3 of distilled water for 100gm of dry ash for determination of potassium ion from red mangrove bark aqueous extract (RMBAE). Finally, the purity level (69.64) illustrated that potassium content of red mangrove bark aqueous extract is a good quality food additive with good nutritive and medicinal properties as a good salt (KCl) substitute for sodium chloride that causes high blood pressure and a good plant source for potassium ions. Hence, the proposed methods could be employed for routine analysis of mineral composition in various plants, fruit extracts, vegetables etc.

REFERENCES [1] Berenquer B, Sanchez LM, Quile A, Lopez-Barrero M, De H, Galvez J, Martin MJ. Protective and antioxidant effects of Rhizophora mangle L. agent NSAID-Induced gastric ulcers. J. Ethnophamacol 2006; 103(2):194-200. [2] De Armas E, Sarracent Y, Marrero E, Femandez O, Branford-White C. Efficacy of Rhizophora mangle aqueous bark extract (RMBAE) in the treatment of aphthous ulcers: a pilot study. Curr Med Res Opin. 2005; 21(11): 1711-1715.

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[3] Hernes PJ, Cowic BR, Goni GL, Bergamaschi MA, Hedges JI. Tannin digenesis in mangrove leaves from tropical estuary. A novel molecular approach. Geo Chim.Cosmo Chim. Acta. 2001; 65: 3109-3122. [4] Manikandan T, Neclakandan T, Usha RG. Effects of salinity on the growth, photosynthesis and mineral constituents of the red mangrove Rhizophora Apiculata L seedlings. Recent Research in science and technology 2009; 1(3): 134-141. [5] Karamac M. Chelation of Cu(II), Zn(II), Fe(II) by tannin constituents of selected edible nuts. Ini. J. Mol. Sci. 2009; 10: 5485-5497. [6] Solomon Raja AJ, Henry Jonathan K, Rao PS. Traditional extraction of bark tannin from the mangrove tree, Ceriops decandra(Griff.) Ding Hou and its uses in treating cotton fishing nets. Natural Product Radiance 2008; 7(2): 173-175. [7] Mianpeuren T, Mbaiguinam M, Nambatingai N, Yaya M, Ngarmadji A. Elemental compostion of vegetable salts from ash of four common plant species from Chad. International Journal of pharmacology 2012; 8(6): 582-585. [8] Seey TL, Noordin MJ, Mohd Kassim. Characterization of mangrove bark adsorbent and its application in the removal of textile dyes from aqueous solutions. Journal of applied phytotechnology in environmental sanitation 2012; 1(3): 121130. [9] Sanchez PLM, Melchor G, Alvarez S, and Bulnes C. Chemical and toxicological characterization of one wound healing formulation from Rhizohpora mangle L. Rev. Salud Animal. 1998, 20: 69-72. [10] Sanchez PLM, Varcalcel L, Escobar A, Noa M. Polyphenol and pyhtosterols. Compositions in antibacterial extract from Rhizophora mangle L.’s bark. J. Herbal Pharmacother. 2008; 7: 107-128

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