Petroleum Iodine value of Oil and Fat - kyoto-kem.com

1 Petroleum Iodine value of Oil and Fat Redox titration by Automatic Potentiometric Titrator Standard JIS K 0070 ASTM D 1959 ISO 3961 Test method for measurement of Iodine value of fats and oils stipulated in the below quoted standards is generally practiced by Wijs Method using monobasic Iodine , however, Hanus Method is demonstrated here using Iodine bromide. Firstly, sample fat is dissolved in carbon tetrachloride, and Hanus reagent is added and left in a dark room for reaction. Then, potassium iodide is added for titration with sodium thiosulfate. The endpoint is the maximum inflexion point on titration curve. The Iodine value of fatty sample is calculated from titration volume of sodium thiosulfate. 4I2 + Na2S2O3 5H2O 2 NaI + H2SO4 HI 1) JIS K 0070-1992 Test Method for Acid value , Saponification number, Ester number, Iodine number, Hydroxyl value of Chemical products and Unsaponifiable matter 2) ASTM D 1959-97 Standard Test Method for Iodine value of Drying Oils and Fatty Acids 3) ISO 3961:1996 Animal and vegetable fats and oils Determination of Iodine value in measurement 1) Reagent and additives must be handled in a well ventilated room or in a draft.

2 2) Blank test is required as necessary. 3) Use a 300mL conical flask with ground-in stopper to avoid sublimation of Iodine when the sample and Hanus solution react. TIB-99424 1/4 TIB-99424 2/4 care Rinse the electrode with pure water, and keep it dipped in water to avoid drying up. equipment Main unit: Automatic potentiometric titration system (preamplifier: STD) Electrode: Option Combination platinum electrode Reagent sodium thiosulfate Additives Pure water, Carbon tetrachloride, Hanus solution, 15% Potassium iodide procedure Measurement 1) Deliver sample to a 300 L conical flask with ground-in stopper. Add carbon tetrachloride and seal. Dissolve in an ultrasonic washing machine. 2) Add Hanus solution, and seal. Shake for one minute. 3) Keep it sealed and leave in a dark room (about 20 C) for 30 minutes. 4) Add of 15% potassium iodide and 100 L water, and seal.

3 Shake for 30 seconds. 5) Titrate with sodium thiosulfate to obtain Iodine value . Likewise, perform blank test to obtain blank level. Iodine value ( c / g ) = ( BL1 EP1 ) TF C1 K1 / SIZE EP1 Titration volume ( mL ) BL1 Blank level ( ) TF Factor of titrant ( ) C1 Concentration conversion coefficient ( ) (Atomic mass of Iodine : ) K1 Unit conversion coefficient ( 1 ) SIZE Sample size ( ) of measurement Ambient condition Room temperature 23 C Humidity 23 Weather Rainy -Titration parameter- -Titration curve- Model : AT-510 Method No. : 10 : Auto Intermit : EP Stop [Titration parameter] Form : EP Stop APB No. : 1 Unit No. : 1 Detector No. : 1 Unit : mV : Wait Time : 0s Direction : Auto [Control parameter] End Point No.

4 : 1 End sense : Auto End Point Area : Off Separation : Off Over : 0mL Gain : 1 Data : Data : Stability : Delay Time : 1s Limit Time : 30s [Result parameter] <Calculation> Calc. Type : Sample : Set CO1= (BL1-EP1)*TF*C1*K1/SIZE Unit : cg/g EP No. : 1 : Off <Constant> C1 : K1 : 1 <Titr. Constant> Factor : Conc : <Blank> Blank1 : (The above printout data are obtained from titration by AT-510 unit) Titration parameter Form: of titration / APB No. the burette used in titration / Unit No.

5 : APB Unit File number Detector No.: the detector used in titration/ Unit of potential / Max Volume: of titration Wait Time: before titration starts/ Direction.: of titration Control parameter End Point No.: number of EPs / End sense: of EP detection / End Point Area: EP detection area Separation: of potential / Over over-titrated volume / Gain: sensitivity of detection signal Data : potential change of sampling signal / Data : titration volume of sampling signal Stability: of EP potential / Delay Time: before stability check / Limit Time: of stability check Calculation parameter : of formula / formula 1 / Unit: of results EP No. of calculation / : temperature compensation / C1(mg/mL): concentration conversion coefficient K1: unit conversion coefficient / Factor: factor of titration liquid / Blank1: blank level 1 TIB-99424 3/4 Measurement results n Sample g Titration (mL) Iodine value (cg/g) Iodine value 1 2 3 Mean SD RSD cg/g cg/g % The above test results are obtained by 3 tests of the same sample.

6 Red underline shows the data from page 3/4. The Iodine value is expressed in grams of Iodine for the amount of halogens linked with 100g test sample, and is used as degree of unsaturated bond of fats and oils. Iodine value is used to compare the number of C=C contained in natural complex mixture. Measurement results this time shows favorable repeatability with relative standard deviation. Precise and reliable measurement is assured by the automated potentiometry. The Iodine value of fats and oils can be perfectly measured by any of the following titration systems manufactured by Kyoto Electronics (KEM). AT-610 AT-510 Compact and cost performance model PC card expands data memory for convenience and versatility. AT-500N-1 Low cost and high performance Easy view with back light LCD GLP/GMP conformed model Awarded Product of Supreme Technology from Kyoto City Easy key entry by touch panel of large color LCD 8-inch wide Simultaneous titration in parallel Both potentiometric and Karl Fischer moisture titration (coulometric volumetric can be performed at a time.)

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