Saponification defined

Saponification number (DIN 51 559). The saponification number is indicative of the presence of ester groups in a resin. The saponification number is defined as the consumption of potassium hydroxide in milligrams by one gram of resin under standardized conditions. 

Discussion. For oils and fats, which are esters of long-chain fatty acids, the saponification value (or number) is defined as the number of milligrams of potassium hydroxide which will neutralise the free fatty acids obtained from the hydrolysis of 1 g of the oil or fat. This means that the saponification number is inversely proportional to the relative molecular masses of the fatty acids obtained from the esters. A typical reaction from the hydrolysis of a glyceride is ... 

When the related saccharin derived sultam (R)-29 is converted into the (Z)-boron enolate and subsequently treated with aldehydes,. vy -diastereomers 30 result almost exclusively. Thus, the diasteromeric ratios, defined as the ratio of the major product to the sum of all other stereoisomers, surpass 99 1. Hydroperoxide assisted saponification followed by esterification provides carboxylic esters 31 with recovery of sultam 32106a. 

For the purpose of the identification and quantification of additives (broadly defined) in polymeric materials extraction and dissolution methods are favoured (Sections 3.3-3.7). However, additives are also made accessible analytically by digestion of the sample matrix (cf. Section 8.2). Such wet chemical techniques, that remove the sample matrix first, are often limited to mg amounts because of pressure build-up in destruction vessels. Another reactive extraction approach to facilitate additive analysis is depolymerisation by acid hydrolysis or saponification, sometimes under pressure. This is then frequently followed by chemical methods such as titrimetry or photometry for final identification and quantification. 

In this group we place mainly the neutral bacterial slimes and reserve carbohydrates. They are better defined products than those previously dealt with and as such may of course be regarded as true polysaccharides. Invariably, however, saponification methods are required to rid them of protein residues and to make them water-soluble. The more soluble mold polysaccharides appear to lose their protein constituents by autolytic processes during the longer periods required for mold metabolism. Mold slime production can, however, readily be demonstrated on a solid medium. It is proposed here to give briefly some of the types of structure known in the group. 

Electrolyte dissolved fuel alkaline fuel cells, 12 216 Electrolytes AFC, 12 215 aqueous, 9 591-593 batteries, 3 415-418 in continuous saponification, 22 738 defined, 3 409... 

An early synthesis of A5-palmitoy]-.S -[2,3-bis(palmitoyloxy)propyl]cysteine employed cysteine methyl ester, however, this leads to difficulties in the saponification step of the tri-palmitoylated residue. 96 The optimized procedure, in which the cystine di-fert-butyl ester is used, 90 is outlined in Scheme 6 after N-acylation with palmitoyl chloride, the ester is reduced to the cysteine derivative for S-alkylation with l-bromopropane-2,3-diol to yield chirally defined isomers if optically pure bromo derivatives are used. Esterification of the hydroxy groups is best carried out with a 1.25-fold excess of palmitic acid, DCC, and DMAP. The use of a larger excess of palmitoyl chloride is not recommended due to purification problems. The diastereomeric mixture can be separated by silica gel chromatography using CH2Cl2/EtOAc (20 1) as eluent and the configuration was assigned by comparison with an optically pure sample obtained with 2R)- -bromopropane-2,3-diol. 

Even a single molecule is not usually a completely defined object because it is not rigid. An example is provided by cA-1,2-disubstituted cyclohexanes such as dimethyl c/. r-l,2-cyclohcxanedi-carboxylatc. A detailed physicochemical investigation by low-temperature spectroscopy or a detailed mechanistic study (e.g., enzyme-catalyzed semi-saponification of the diesteij, would require an analysis in terms of equilibrating enantiomers 1 of point group C. However, for most practical purposes, e.g.. a manufacturer s catalog, the Haworth-type formula 2 of a Cs-symmetric species would suffice. 

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 saponification value is the amount of alkali required to saponify a defined amount of sample. It is expressed in mg potassium hydroxide (KOH) per g sample. The procedure involves the use of excess alcoholic KOH, which catalyzes the saponification/release of the free fatty acids from the glycerol backbone. The unreacted KOH is then back-titrated with standardized hydrochloric acid (HC1) using phenolphthalein as the indicator. The amount and normality of the HC1 used for neutralization can then be used to calculate the saponification value. The saponification value provides evidence as to the relative chain lengths of the fatty acids in the system. 

Iodine and saponification numbers are often determined in industries concerned with lipid products. The iodine number is defined as the number of grams of iodine (I2) that reacts with 100 g fat. The saponification number is mg KOH required to hydrolyze 1 g triglyceride. Now suppose that you have 5 g triglyceride and it required 980 mg KOH for hydrolysis and 4.45 g I2 to react with the unsaturated fatty acids therein. Calculate or determine the following ... 

The saponification value is defined as the number of mg of potassium hydroxide required to neutralize the free acids and saponify the esters in 1 g of the test substance. 

Starting with intermediate 145 (Scheme 26), 147 was prepared using dihydrocinnamoyl chloride, followed by catalytic hydrogenation and saponification of the ester group. The cyclization step was performed in the same manner as described above (see Scheme 27). The resulting product 148 was identical to the analogous derivative obtained from natural periphylline therefore, periphylline must possess structure 138 (775). The chirality of center-11 has been defined as S by ORD measurement in relation to the alkaloids chaenorhine and homaline (113). 

Solvolysis (chemolysis) is defined as a techniqne which obtains the raw materials, snch as TPA, DMT, EG monomers and oligomers as the reverse process of PET prodnction by saponification or transesterification with water, methanol or EG. For the process of PET production raw materials of high purity are obligatory. Polycondensation is not a chain reaction, but a step reaction. Impurities can stop the polycondensation at low molar masses, so high-purity standards are also reqnired for the solvolysis prodncts. The choice of process depends on the starting material and the demand for solvolysis prodncts. 

Saponification value (SV) Defined as the number of milligrams of potassium hydroxide required to hydrolyze (saponify) 1 g of fat. The higher the SV, the lower the mean chain length of the component fatty acids of an acylglycerol. 

Other parameters that are indirectly related to the composition of edible oils include iodine value and saponification value. The iodine value is a simple chemical constant for a fat or oil. It measures unsaturated or the average number of double bonds in fats and oils. Iodine value is defined as the number of grams of iodine that could be added to 100 g of oil, which is measured with the AOCS Method cd 1-25 (22). Meanwhile, saponification value is a measure of the alkali-reactive groups in fats and oils and is defined as the mg of KOH needed to saponify 1 g of oil. Shorter chain fatty acids give higher saponification values than do longer chain fatty acids. 

The saponification value is defined as the weight of potassium hydroxide, in milligrams, needed to saponify 1 g of fat. This parameter is inversely proportional to the molecular weight of the fat. In other words, the higher the molecular weight, the lower the saponification value. Replacement of long-chain fatty acids such as erucic acid in canola oil by octadecenoic fatty acids increased the saponification numbers from 168-181 to 188-192 because of the reduction in molecular weight (Table 13). 

Insoluble Acids, Hehner Value.—The acids which are set free from the fat or oil by saponification and subsequent acidification, differ in two other respects as well as in their power to absorb halogens. These are, (i) solubility (2) volatility. - Some of the acids, like butyric, are soluble in water while most of them are insoluble. Some, like butyric and lauric, are volatile with steam, others are non-volatile. The determination of the amount of insoluble acids in a fat gives us a value known as the Hehner Value which may be defined as the sum of the insoluble acids and unsaponifiable matter in a fat expressed in per cent. After saponification of the fat the soap solution is acidified and the insoluble fatty acids are collected on a filter paper and weighed. In the case of most of the common fats and oils the Hehner value lies in the neighborhood of 95, with butter fat as the striking exception, with a value of less than 90. The Hehner values which differ much from 95 are given in the table at the end of this section. 

P12C-2 Use the references given in Ind. Eng. Chem. Prod. Res. Lev. /4, 226 (1975) to define the iodine value, saponification number, acid number, and experimental setup. Use the slurry reactor analysis to evaluate the effects of mass transfer and determine if there are any mass transfer limitations. 

Saponification number It is defined as milligrams of KOH required to saponify 1 gm of fat or oil. Saponification number is high for fat or oil containing low molecular weight or short chain fatty acids and vice versa. It gives a clue about the molecular weight and size of the fatty acid in the fat or oil. 

Acetyl Number It is defined as the amount in millilitres of potassium hydroxide solution required to neutralise the acetic acid obtained by saponification of 1 gm of fat or oil after acetylation. Some fatty acids contain hydroxyl groups. In order to determine the proportion of these, they are acetylated by means of acetic anhydride. This results in the introduction of acetyl groups in the place of free hydroxyl groups. The acetic acid in combination with fat can be determined by titration of the liberated acetic acid from acetylated fat or oil with standard alkali. Acetyl number is thus a measure of the number of hydroxyl groups present in fat or oil. 

Three moles of KOH are required to saponify one mole of triglyceride. The saponification number is defined as the number of milligrams of KOH required to saponify 1-0 g of triglyceride. 

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