Viscometric, Volumetric and Thermodynamic Studies L-Alanine in Aqueous and Ethanol Media at K

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1 5 IJSRST Vlume Issue 3 Print ISSN: 3956 Online ISSN: 3956X Themed Sectin: Science Viscmetric, Vlumetric and Thermdynamic Studies LAlanine in Aqueus and Ethanl Media at K Abideen Idwu Adegun*, Mpella Abidemi Idwu, Sikiru Akinyeye Ahmed 3, Ninila Mariam Oyedkun Chemistry Department Federal Uniersity f Agriculture, Abekuta, Nigeria Pllutin Cntrl Diisin, Central Electrchemical Research Institute, Karaikudi, 636, Tamil Nadu, India 3 Chemistry Department Ond State Uniersity f Science and Technlgy, Okitipupa, Nigeria ABSTRACT Valuable infrmatin regarding slute slent, slute slute and slent slent interactins are btainable frm lumetric, iscmetric and ther thermdynamic data in a slute slent system. Cnsequently we study the density and iscsity f LAlanine in aqueus and ethanl media as a functin f cncentratin at the temperature ranges between 93 and 33 K. The apparent mlar lume (φ υ ) f the amin acid is linearly related t its cncentratin in the tw media. Apparent mlar lume at infinite dilutin ( ) were estimated frm least square fit f s mlarity. Viscsity cefficients A and B were calculated frm the iscsity data Jnes Dle equatin. The actiatin parameters fr iscus flw, S, and H were als estimated using Eyring equatin. The data are explained isàis structure making r breaking effect f LAlanine at the temperature under cnsideratin. Key wrds: LAlanine; ethanl; apparent mlar lume; infinite dilutin; structure breaking and structure making I. INTRODUCTION The physicchemical prperties f slutes in slutins pride aluable infrmatin n slute slent, slute slute and slent slent interactins. When applied t prteins, infrmatin that are imprtant in understanding their stability and seeral ther bichemical and physilgical prcesses in a liing cell are btainable (Pal et al., 9; Zha, 6; Zhu et al., 5; Banipal et al., 9; Nain, 3; Thirumaran and Imban, ). Prteins are large cmplex mlecules with high difficulty in direct study f their interactins with slents. Therefre, ne useful apprach is t inestigate interactins f the mdel cmpunds f prteins, i.e. amin acids, in aqueus r mixed slent system. The extensie studies f lumetric prperties f amin acids in arius slent media can act as effectie prbes f their cnfirmatin and prperties in slutins (Wadi et al., 99; Banipal et al., 4; Yan et al., ). LAlanine, a nnessential αamin acid is manufactured by the human bdy and des nt need t be btained directly thrugh the diet. It is manufactured in the lier frm ther amin acids. It is ne f the mst widely used amin acids in the fabricatin f prteins, reinfrcing their flexibility, fibrestrength and resilience. It is readily cnerted t glucse when bld sugar leels fall. Life style, wrk place and dietary are majr surces f getting alchl absrbs int the bdy system, with effects depending n amunt absrbed. When mixed with bdy fluids can affect the cnfrmatin, transprtatin and the prducts f their reactins. In this study we desired t study LAlanine in aqueus and ethanl system under different cnditins t see whether it has n net effect n water and ethanl structures either by enhancing r breaking their structure. IJSRST53 Receied: 7 August 5 Accepted: August 5 JulyAugust 5 [()3: 96] 96

2 II. METHODS AND MATERIAL Lalanine (98.5 %) and Ethanl (99.8 %) were frm BDH, Lndn. LAlanine was recrystallized in water + ethanl and dried in desiccatr fr 4 hurs prir t use. Water fr the slutins was dubly distilled. The densities were measured by using a 5 ±. ml density bttle. The iscsities were measured by the Ubbelhde iscmeter (Calibrated CUC (97K5) Series) frm Cannn Instrument with sufficiently lng efflux time t aid kinetic energy crrectin. The time f flw was recrded by electrnic digital clck capable f reading up t. s. A METTLER PM electrnic balance with accuracy f. g was used fr weighing. The temperature was cntrlled by a thermstatic water bath fluctuating t ±. C. III. RESULTS AND DISCUSSION The alues f densities (ρ) and iscsities (η), btained fr arius cncentratins f LAlanine in water and ethanl at T = (93.5, 98.5, 33.5, 38.5, and 33.5) K are listed in Tables and. The apparent mlar lumes, ( ) were calculated frm ρ data using the fllwing relatin: ρ (ρ ρ) ρ ρm () υ M where ρ and ρ are the densities f slutin and slent (water r ethanl), respectiely, m is the cncentratin f the slute (LAlanine) in mlality and M is its mlar mass f the slute. The apparent mlar lume at infinite dilutin ( ) was btained using a leastsquare fit t the linear plts f s m using the Massn equatin (Massn, 99): m () S where S is the experimental slpe, als knwn as the lumetric pairwise interactin cefficient (Desnyers, 98; Hedwig, 99). The alues f the limiting apparent mlar lume, and the lumetric pairwise interactin cefficient, S are als presented fr LAlanine in ethanl and water are as shwn in Tables and. There are slight ariatins in the alues f and as the temperature aries. The psitie alues f (Tables and ) suggest the presence f strng slute slent interactins in these media thrughut the LAlanine cncentratins and temperatures under inestigatins. The ariatin f with mlar cncentratin f LAlanine can be explained with csphere erlap mdel (Gurney 953). This mdel assumes that hydrphilic inic grup interactin resulted in psitie cntributin t and that negatie cntributin is due t hydrphilichydrphbic interactins. The zwitterinic frms f amin acids (i.e. NH + 3, COO ) as well as their side chains play significant rles in their interactin with slents in hence a psitie alue f (Banipal et al., 9, Nain 9). The trends are als presented in Figures and. Table : The density (ρ), iscsity (η), partial mlar lume ) apparent mlar lume ( ) and pairwise cefficient ( ( S ) f LAlanine in Water at arius cncentratin and temperature. Temp /K Table : The density (ρ), iscsity (η), partial mlar lume )apparent mlar lume ( ), pairwise cefficient ( S ) ( mlality. /(ml kg ) and transfer lume, ρ /(g cm 3 ) arius cncentratins and temperature. η /(Ns m ) /(cm 3 ml ) /(cm 3 ml ) S /(cm 3 dm 3/ ml ) f LAlanine in ethanl at Internatinal Jurnal f Scientific Research in Science and Technlgy ( 97

3 Temp /K mlality /(ml kg ) ρ /(g cm 3 ) η /(Ns m ) /(cm 3 ml ) /(cm 3 ml ) S /(cm 3 dm 3/ ml ) cnfirmatin f attractin between the slute and slent mlecules. The temperature dependence f was accrding t the relatin in equatin 3 belw: a at a3t (3) Figures 3 and 4 als depict the ariatins in the limiting apparent mlar lume with temperature. Table 3: Values f cefficients ai fr LAlanine in water and ethanl Cnc (ml dm 3 ) Cefficient f expansin Alanine Ethanl system a a / a 3/ (cm 3 ml ) (cm 3 K ) ml (cm 3 ml K ) Cefficient f expansin (Alanine water system) a / a / a 3/ (cm 3 ml ) (cm 3 ml (cm 3 K ) ml K ) Figure : Partial mlar lume s cncentratin fr Ethanl Alanine system. Figure 3: Change in limiting apparent mlar lume with temperature in ethanl L alanine system. Figure : Partial mlar lume s cncentratin fr Water Alanine system The negatie alues f S btained fr LAlanine in the tw slents suggested weak slute slute r in in interactins., the intercept, which is the limiting apparent mlar lume f the slute, prides infrmatin cncerning slute slent interactins. Tables and als reealed increasing density f L Alanine with increasing cncentratins; this is als a Figure 4: Change in limiting apparent mlar lume with temperature in water L alanine system. Values f cefficients a i and the limiting apparent mlar expansiity btained by least square fit are T presented in Table 3 and 4. The alues limiting apparent mlar expansiity decreases with increasing temperature in ethanl which is a clear indicatin f Internatinal Jurnal f Scientific Research in Science and Technlgy ( 98

4 cmmn salt behaiur, and that at high temperature bnded slent mlecules are less hence expansiity becme weaker (Huiyng et al., ). The increase in temperature lead t increase in the mlar expansiity at.5 and. ml dm 3 this is attributed t cmplete sluteslent csphere behaiur f alanine in water at these cncentratins. The alues thermal expansiities estimated (Table 4) shwed that T LAlanine is a structure maker in bth slents with mre effect in water than in ethanl at high cncentratin (Gupta and Sigh, 5). Table 4: Values f cefficients Limiting apparent mlar and thermal expansiity fr LAlanine in water and ethanl Temp /K T T Cnc/ Limiting apparent mlar expansibility in water Limiting apparent mlar expansibility (Ethanl) (ml dm 3 ) T T Table 5: Viscsity cefficients and Actiatin fr iscsity f LAlanine in Water and Ethanl Water + L Alanine Ethanl + L Alanine (Temperature /K) A /(dm 3/ ml / ) B /(dm 3 ml ) /(kj ml ) /(kj ml ) T S /(kj ml ) H /(kj ml K ) The iscsity was determined frm the relatie iscsity using the relatin: (4) t t where η, t and ρ are the abslute iscsity, time f flw and density f slutin, while, t and ρ are same quantities fr the slent (water r ethanl). The iscsity data was analysed by least square fit f relatie iscsity s cncentratin ariatin accrding t Jnes Dle equatin belw: A* C B C (5) r * where r is relatie iscsity, C is mlar cncentratin the cnstant A is the Falkenhagen cefficient and B is the JnesDle cefficient related t sluteslent and sluteslute interactin respectiely. The alue f iscsity cefficient A is assciated with the size f the sluteues f cefficients A and B f the Jnes Dle equatin hae been determined and the results is presented in Table 5 alng with thermdynamic parameters f disslutin f LAlanine in water and alchl. Figures 5 and 6 als depict the change in iscsity with increase cncentratin f L alanine in water and ethanl respectiely. It is bsered that the alues f A are psitie, while the alues f B are negatie in bth slent. This is a clear indicatin f presence f strng inic interactins between the Lalanine mlecules but weak in slent interactins. Internatinal Jurnal f Scientific Research in Science and Technlgy ( 99

5 Figure 5 : Change in iscsities with temperature in ethanl L alanine system. Figure 6: Change in iscsities with temperature in water L alanine system. The thermdynamic prperties were estimated using the Nightingale and Benck and Eyring equatins (Hssain et al., ). The aerage Gibbs energy f actiatin, f a slute fr iscus flw in a slent can be calculated frm the iscsity by the relatin: RT ln V hn A (6) IV. CONCLUSION The density and iscsity f LAlanine in water and ethanl as a functin f cncentratin at the temperature ranges between 93 and 33 K hae been studied. The results were used fr the estimatins f partial mlar lume (φ υ ), apparent mlar lume at infinite dilutin ( ), and iscsity cefficients A and B. The actiatin parameters fr iscus flw, S, and H were als estimated using Eyring equatin. The data were explained isàis structure making r breaking effect f LAlanine at the temperature under cnsideratin. This study shws that there greater slute where, h and N A are the slent iscsity, Planck s cnstant and Agadr s number, respectiely, and V is the aerage mlar lume which is practically equal t. The actiatin Gibbs energy, fr iscus flw f the LAlanine in water and ethanl is related t the cefficient B f iscsity by: B ( V V ) V RT (7) Upn rearrangement the expressin in Eq. (7) abe becmes: RT V B V V (8) where V is the mlar lume f the slute, R is gas cnstant and T is the abslute temperature respectiely. The calculated alues f and alues are psitie fr all the studied systems as displayed in Table 5. This is interpreted n the basis f slute slent interactin leading t the frmatin f mre structured systems. Other actiatin parameters i.e. H and S were btained frm the relatins: H T (9) S Cnsidering the actiatin parameters, the actiatin Gibbs energy, in the tw slent seems t be clser, which accrding t Feakin s mdel (Feakins et al., 974) that the higher this alue is the greater is the structure making ability. Therefre the slute may be said t hae similar effect n the slute as regard the structure making with a little ariatin based n cncentratin. The alues f S btained suggest that the attainment f transitin state fr iscus flw is by bnd frmatin. The alues f suggested that additinal wrk is required t dissle LAlanine in water than ethanl. slute interactin between Lalanine mlecules than inic interactins with the slent mlecules. V. REFERENCES [] Banipal, P. K.; Chahal, A. K. and Banipal, T. S. (9): Studies n Vlumetric Prperties f Sme Saccharides in Aqueus Ptassium Chlride Slutins er Temperature Range (88.5 t 38.5) K. Jurnal f Chemical Thermdynamics., 4, [] Banipal, T. S., Lark, B. S., Patyar, P. and Kishre, N. (4): Densities, partial mlar lumes and Heat capacities f glycine, Lalanine and L leucine in aqueus magnesium chlride slutins H Internatinal Jurnal f Scientific Research in Science and Technlgy (

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