Determination saponification value

The American Society for Testing and Materials (ASTM) and the American Oil Chemists Society (AOCS) provide standard methods for determining properties that are important in characterization of dimer acids. Characterization of dimer acids for acid and saponification values, unsaponiftables, and specific gravity are done by AOCS standard methods ... 

It is soluble in about 5 volumes of 70 per cent, alcohol. This ester has the character of being saponified much more slowly than most other esters, so that in any determination in which it is involved it is necessary to saponify the sample for two hours before it is safe to consider the reaction complete. This fact also assists in determining whether terpinyl acetate is present as an adulterant in natural essential oils, for if the saponification value as determined by thirty minutes saponification is materially lower than that as determined by a two hours saponification, it may be fairly safely inferred that terpinyl acetate or some similar ester is present. 

Strictly speaking the amount of free acids present in an essential oil should be determined, and the acid value deducted from the saponification value, the difference being the ester value. 

To determine the saponification value 1 of a fat 0-5-1-0 g. is boiled under reflux condenser for half an hour with 10 c.c. of 0-5 A-alcoholic KOH solution and the excess of alkali is then titrated with 0-5 2V-HCI, and phenolphthalein as indicator. 

Some of these tests cover very broadly the general chemical makeup of waxes. Constants such as acid, ester, saponification and iodine numbers can be used to identify, differentiate or classify waxes chemically (Ref 59). Specific tests are used to determine the values of these numbers for waxes. The saponification number generally indicates the total quantity of both esters and free acids in a wax. The acid value is an indication of the quantity of free fatty acids. The ester value is the relative quantity of esters... 

This unit defines three different tests that are used to evaluate lipid systems. The first two, i.e., iodine value (IV see Basic Protocol I) and saponification value (SV see Basic Protocol 2), are used to determine the level of unsaturation and the relative size (chain length) of the fatty acids in the system, respectively. The free fatty acid (FFA) analysis (see Basic Protocol 3) is self-explanatory. Each of these analyses provides a specific set of information about the lipid system. The IV and SV provide relative information this means that the data obtained are compared to the same data from other, defined lipid systems. In mixed triacylglyceride systems there is no absolute IV that indicates the exact number of double bonds or SV that indicates the exact chain length. The data from the FFA analysis is an absolute value however, the meaning of the value is not absolute. As a quality indicator, ranges of FFA content are used and the amount that can be tolerated is product and/or process dependent. 

The MMA homopolymer and the unreacted PVA are removed from the reaction product by the selective extraction method. The grafted branch PMMA is separated from the backbone by oxidative cleavage of all 1,2-glycols of PVA (about 2 mole%)29 Molar masses of the isolated graft copolymers and the separated branches are osmo-metrically determined, after acetylation of hydroxyl groups in benzene. The chemical composition of the graft copolymers is determined from the saponification value of the acetylated sample. 

Saponification Value of Fats and Oils (Cd 3-25) determines the number of milligrams of (alcoholic) potassium hydroxide necessary to saponify a 1 -g sample of a fat or oil. Schaal Test (Schaal Oven Method) an accelerated test for determining the oxidative stability of a fat or a fat-containing food product. Results are reported as the time elapsed until a rancid odor is detected. This is not an AOCS method see American Association of Cereal Chemists Method Manual. Modifications, using OSI apparatus, have been reported. 

Saponification Value Determine as directed under Saponification Value, Appendix VII. 

Saponification Value Determine as directed in Saponification Value under Esters, Appendix VI, using about 1 g of sample, accurately weighed. 

Melting Range Determine as directed in Procedure for Class II under Melting Range or Temperature, Appendix IIB. Saponification Value Determine as directed under Saponification Value, Appendix VII. 

Lead Determine as directed for Method II in the Atomic Absorption Spectrophotometric Graphite Furnace Method under Lead Limit Test, Appendix TTTB, using a 10-g sample. Residue on Ignition Determine as directed under Residue on Ignition, Appendix IIC, igniting a 10-g sample. Saponification Value Determine as directed under Saponification Value, Appendix YU, using about 2 g of sample, accurately weighed. 

Saponification Value after Acetylation Determine as directed under Total Alcohols, Appendix VI, using about 2.5 g of acetylated oil, accurately weighed. Calculate the saponification value by the formula... 

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