Determination of Saponification and Iodine Number of Some Lipids

1655 Words Feb 17th, 2013 7 Pages
DETERMINATION OF SAPONIFICATION AND IODINE NUMBERS OF SOME LIPIDS

A.L. ASCANO1 C.V. OPONDA1
1INSTITUTE OF BIOLOGY
UNIVERSITY OF THE PHILIPPINES, DILIMAN, QUEZON CITY, PHILIPPINES
DATE PERFORMED: FEBRUARY 19, 2013
INSTRUCTOR’S NAME: FRANCESCA N. BELTRAN

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ABSTRACT
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INTRODUCTION

Lipids are long aliphatic hydrocarbon chains which are either branched or unbranched that can form rings and may have unsaturation. [8] They are products of animal or vegetable origin which are extracted with either ether, chloroform, benzene, petroleum, carbon disulfide. [6] They can be
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Thiocyanogen number determines the amount of linoleic acid in a mixture. [5] Tiration Euivalen wight os the average molecular weight of a fatty acid mixture.

Objectives addressed in this experiment includes: (1) characterization of oil samples by determination of saponification and iodine numbers (2) estimation of molecular weights of fat or oil sample (3) explain the methods employed in the characterization of oil or fat samples

METHODOLOGY

Determination of Saponification Number

Oil used were lauric oil, vegetable oil and lard. Each triacylglycerol was weighed to 1.0g. Each were placed n separate round bottom flask.. 15mL of 5% alcoholic KOH was added into each flask from a burette. KOH was used in order to hydrolyze the glyceryl esters to glycerol and the potassium salts of fatty acids. Alcoholic KOH was used to allow oil be soluble in it. [1] Two to three pieces of boiling chips were added so as to prevent formation of large bubbles [1]. It was then subjected to reflux for an hour. After which, it was then cooled to room temperature. The solution was then transferred into an Erlenmeyer flask. Small amounts of hexane were added to rinse of remaining oil from the round bottom flask. It was then titrated with 0.5M HCl, using 1% phenolphthalein as the indicator. Volume of KOH used was used to determine the saponification number by using the eq. 2

Determination of Iodine

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