Saponification Value of Oil

Only available on StudyMode
  • Download(s) : 138
  • Published : August 20, 2012
Open Document
Text Preview
Fat and Oil

Saponification value of Fat and Oil

Acid⋅base titration (non aqueous) by Automatic Potentiometric Titrator Standard
JIS ASTM ISO K 0070 D 5558 3657 Standard Test Method for Fat and Oil

1.Abstract
Saponification value is expressed by potassium hydroxide in mg required to saponify one (1) gram of fat. It depends on the kind of fatty acid contained in the fat. Measurement of saponification value is performed according to the below listed official test methods. Here we test a sample of fatty acid. The sample is first saponified by adding 0.5mol/L potassium hydroxide ethanol, and then the excessive potassium hydroxide is titrated with 0.5mol/L hydrochloric acid until the endpoint is reached. EP is determined by the maximum inflexion point on titration curve. R COOH + KOH KOH + HCl → → R COOK + H2O KCl + H2O

2.Reference
1) JIS K 0070-1992 Test Method for Acidity, Saponification value, Ester value, Iodine value and Hydroxy value of Chemical products and Unsaponifiables 2) ASTM D 5558-95 Standard Test Method for Determination of the Saponification Value of Fats and Oils 3) ISO 3657 : 2002 Animal and vegetable fats and oils – Determination of saponification value 4) Method (I) 3.3.2-1996 Saponification Value from Standard Test Method for Fat and Oil by Japanese Oil Chemistry Society

3.Cautions in measurement
1) When the sample is heated in flask for saponification, gently heat it so that backflow ethanol will not reach the top of cooling pipe fitted to the flask. 2) Replace junction liquid of reference electrode with saturated sodium perchlorate acetic acid.

TIB-99307 Ver.01 1/4

4.Post-measurement care
After the electrode is rinsed with water, keep the tip of electrode dipped in pure water for storage.

5.Test equipment
Main unit:Automatic potentiometric titrator (Standard preamplifier STD-) Electrode: Standard Combination glass electrode (Change junction liquid to saturated sodium perchlorate acetic acid)

6.Reagent
Reagent Reagent : : 0.5mol/L Hydrochloric acid ( f = 1.006 ) 0.5mol/L Potassium hydroxide ⋅ Ethanol

7.Measurement procedure
一Measurement― 1) Deliver 1.5 to 2.0g sample into a 200mL conical flask. 2) Add 25.0mL of 0.5mol/L potassium hydroxide Ethanol, and fix a cooling pipe to the flask. 3) Gently heat the flask occasionally shaking while adjusting the heat so that backflow ethanol will not reach the top of cooling pipe. 4) After heated for 30 minutes, immediately cool it, and titrate with 0.5mol/L HCl before the test liquid is solidified. 5) Perform blank test (without sample following step 1 to 4 above) for 3 times to obtain mean value of titration volume of 0.5mol/L hydrochloric acid.

8.Formula
Saponification value ( mg / g ) = ( BLl - EPl ) × TF × Cl × K1 / SIZE EPl BLl TF Cl : : : : Titration volume ( mL ) Blank level ( 25.029mL ) Reagent (HCl) factor ( 1.006 ) concentration conversion coefficient ( 28.05 mg/mL ) (Potassium hydroxide in Eq.:56.11×0.5) Unit conversion coefficient ( 1 ) Sample size ( g )

Kl : SIZE :

TIB-99307 Ver.01 2/4

9.Example of measurement
-Ambient condition- Room temperature:22.5 ℃ -Titration parameterModel : AT-510 Method No. : 12 Titr.mode : Petroleum Titr. Titr.form : EP Stop [Titration parameter] Form APB No. Unit No. Detector No. Unit Max.Volume Wait Time Direction : : : : : : : : EP Stop 1 1 1 mV 20.0mL 60s Auto [Result parameter] Calc.Type : Sample Conc.1 : Set CO1= (BL1-EP1)*TF*C1*K1/SIZE Unit : mg/g EP No. : 1 Temp.Comp. : Off C1(mg/mL) K1 : 28.05 : 1

Humidity :

47 %

Weather : -Titration curve*** R e s u l t ***

Cloudy

Sample No. : 22-01 Date : 1999/07/15 09:09 Sample ID : Method No. : 12 Method Name : Titr.time Size Conc-1 : 00:43:31 : 1.6347g : 327.6mg/g

[Control parameter] End Point No. : End sense : End Point Area : Separation : Over Titr.Vol. : Gain : Data samp.Pot. : Data samp.Vol. : Integral Time : Start Lim.Time : Limit Time : 1st Volume : 2nd Volume :...
tracking img