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Determination of Saponification Value and Unsaponifiable Matter
1. Aim
To determine saponification value and unsaponifiable matter from a supervised, validated analytical record. Actual sample and result must be entered in the student record.
2. Requirements
Authenticated oil or fat sample record, validated method sheet, labelled blank and sample titres, standardized reagents, balance record, calculator, protective equipment, and waste instructions. Required inputs: Blank acid titre B, sample acid titre S, acid normality N, sample mass W, and separately measured unsaponifiable residue. Follow the chosen method sheet for reagent amounts, concentrations, and timings. Any assay acceptance limit is to be recorded from the assigned current monograph or approved college method in the student record against the current approved method or monograph.
3. Theory
Saponification value measures the alkali required to saponify esters and neutralize free acids in 1 g of fat or oil. Unsaponifiable matter is the fraction that does not form soap under the prescribed conditions; it needs a separate extraction, washing, drying, and weighing record.
4. Procedure
- Identify the authenticated sample, current method, safety controls, and reporting units.
- Check the balance, reagent standardization, and blank records before using any titre.
- Have the instructor perform or supervise the exact validated analytical procedure; do not substitute an illustrative value for a laboratory setting.
- Record original sample and blank readings, including any replicate and validity check.
- Apply the formula only to accepted readings and compare the result with the applicable specification, if supplied.
5. Observation and calculation
| Student record field | Entry |
|---|---|
| Case or product | Record here |
| Method | Record here |
| Observation | Record here |
| Inference | Record here |
| Supervisor check | Record here |
| Outcome | Record here |
Assumed values for calculation practice only: assumed B = 25.0 mL, assumed S = 10.0 mL, assumed N = 0.50, and assumed W = 2.00 g. Assumed saponification value = 56.1 × 15.0 × 0.50 / 2.00 = 210.375 mg KOH/g. Unsaponifiable matter not calculated because no residue mass is assumed. These invented inputs and output are not a real result, preparation instruction, or acceptance limit. Source formula: Saponification value = 56.1 × (B − S) × N / W, in mg KOH per g; unsaponifiable matter percentage = 100 × corrected residue mass / sample mass. Actual measurements must be entered in the student record.
6. Output or final result
Report the value, unit, method, and validity check for the real sample. Actual result for determination of saponification value and unsaponifiable matter: Record here.
Teaching-lab safety: Titrants and solvents require instructor supervision, ventilation appropriate to the method, and chemical waste collection. Do not prepare reagents from assumed examples.
This page is a supervised-activity guide; it does not report a completed case.
7. Sources
- PharmacoLearn Pharm.D Year 2 syllabus
- PCI Pharm.D Regulations and Syllabus
- WHO Quality Control Methods for Herbal Materials
- Official method or compendial chapter
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