Overview
ISO 1108:1992 specifies a laboratory method for the determination of non-volatile ether extract in spices and condiments. The standard defines the principle, required reagent, apparatus, test procedure, result expression and test report content. It applies to most spices and condiments, though specific products may require adapted methods.
Key topics and requirements
- Scope and principle
- Extraction of sample material with diethyl ether to isolate non-volatile (non-ether‑volatile) substances, removal of volatiles, drying and weighing the non‑volatile residue.
- Reagent
- Diethyl ether, anhydrous, analytical reagent grade (as specified).
- Apparatus
- Continuous‑extraction apparatus (Soxhlet‑type), rotary evaporator, oven capable of 110 °C ± 2 °C, and an analytical balance accurate to ±0.001 g.
- Sampling and sample preparation
- Sampling and ground sample preparation are to follow the referenced ISO methods (see Related Standards).
- Test procedure (condensed)
- Weigh approximately 2 g of test sample to nearest 1 mg.
- Extract with diethyl ether in a continuous‑extraction apparatus for 18 hours.
- Remove ether by distillation (use rotary evaporator), rinse extractor with ~20 ml ether.
- Dry flask and residue in oven at 110 °C until successive weighings differ by ≤ 2 mg.
- Repeat extraction and drying until no more residue dissolves; determine mass changes.
- Expression of results
- Report the non‑volatile ether extract as a percentage by mass on a dry basis. Calculation uses the mass of the test portion, flask/residue masses and the sample moisture content (moisture determined per ISO 939).
- Test report
- Must specify method used, result, all operational details not specified by the standard, and any incidents affecting the result.
Practical applications and users
- Quality control and specification testing in:
- Spice and condiment manufacturers
- Food testing laboratories
- Regulatory bodies and inspection agencies
- Standards and product specification developers
- Typical uses:
- Determining non‑volatile oil and extract content for product specification, labelling, composition analysis and comparative quality assessment.
Related standards
- ISO 939 - moisture content (entrainment method)
- ISO 948 - sampling for spices and condiments
- ISO 2825 - preparation of a ground sample for analysis
Keywords: ISO 1108:1992, spices and condiments, non-volatile ether extract, diethyl ether, continuous extraction, rotary evaporator, analytical balance, quality control.
