รายละเอียดเอกสาร

เคมี

เอกสารมาตรฐาน

สหรัฐอเมริกา

AOCS

Cd 3c-91

Saponification Value, Modified Method Using Methanol

2017

2

665.0288 AOCS 7th ed. 2017-2019 rev. Ref. (Loose-Leaves FL2)

The saponification value is the amount of alkali necessary to saponify a definite quantity of the test sample. It is expressed as the number of milligrams of potassium hydroxide (KOH) required to saponify 1 gram of the test sample. Applicable to fats and oils and fatty derivatives. While it is reasonably accurate and fairly easy to run, AOCS Official Method Cd 3-25 does have definite drawbacks. The problems are most evident to individuals and laboratories that do not perform the analysis routinely. A few improvements have been suggested for difficult materials (References, 1 and 2). The saponification solution must be carefully prepared and is best if made fresh. It tends to turn brown (References, 3) and give inconsistent results within several days because the solution media is ethanol, which contains small amounts of acetaldehyde that self-condense or polymerize. Preparing the solution is inconvenient if only a few determinations are required.