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DD CEN ISO TS 17764 — Determination of Fatty Acids in Animal Feeding Stuffs Standard Series
Animal Feeding Stuffs — Determination of the Content of Fatty Acids — Part 1: Preparation of Methyl Esters / Part 2: Gas Chromatographic Method (CEN ISO/TS Series)
🧪 DD CEN ISO/TS 17764 is a CEN Technical Specification (CEN ISO/TS) issued by BSI in the Draft for Development (DD) series, used to determine the fatty acid content of animal feeding stuffs. The series is identical to ISO/TS 17764:2002, and UK participation was entrusted to Technical Committee AW/10 (Animal feeding stuffs). Because the method still required collaborative trials to validate its robustness, the documents were issued on a provisional basis: a review is initiated no later than 3 years after publication to decide whether the TS can be converted into a formal European Standard. The series comprises two documents forming a complete “sample preparation – instrumental analysis” chain.
⚠️ A “DD” (Draft for Development) document is not a formal British Standard; it is a provisional technical specification. Users should monitor its review and conversion status and apply the latest valid edition.
1. Series Overview and Application Context 📌
The fatty acid composition of animal feeding stuffs (especially oil-supplemented feeds) directly affects animal nutrition, digestion and absorption, and product quality. Determining fatty acid content generally requires two steps: first converting triglycerides and other lipids into volatile fatty acid methyl esters (FAME), then separating and quantifying them by gas chromatography (GC). DD CEN ISO/TS 17764-1 specifies methyl ester preparation and 17764-2 the GC determination, together forming a standardized analytical workflow. The documents are classified under ICS 65.120 (Animal feeding stuffs).
2. Series Structure and Document List 📋
| Standard | Edition | Subject | Stage |
|---|---|---|---|
| DD CEN ISO/TS 17764-1 | 2006 (incl. Amd. 16946) | Fatty acids — preparation of methyl esters | Sample preparation |
| DD CEN ISO/TS 17764-2 | 2006 | Fatty acids — gas chromatographic method | Instrumental analysis |
Note: In February 2007 BSI issued amendment no. 16946, renumbering the original “DD ISO/TS 17764-1:2002” as “DD CEN ISO/TS 17764-1:2006”.
3. Part 1: Preparation of Fatty Acid Methyl Esters 🔧
Part 1 specifies the standard procedure for converting lipids in feed samples into fatty acid methyl esters, including:
- Fat extraction: extract total lipids from the feed using a solvent system (e.g., petroleum ether).
- Methylation reaction: convert glycerides and free fatty acids into FAME under alkaline/acidic catalysis.
- Clean-up and concentration: remove matrix components that interfere with the chromatographic analysis, yielding a methyl ester solution suitable for injection.
💡 Preparation quality determines analysis success: incomplete methylation, residual water, or oxidation cause peak shifts and low quantification. The standard emphasises controlling reaction temperature, time, and reagent freshness, and reporting sample representativeness.
4. Part 2: Gas Chromatographic Determination 🔍
Part 2 gives provisions for separating and quantifying fatty acid methyl esters using a gas chromatograph, including the column (typically a polar stationary phase), carrier gas, temperature program (temperature programming), detector (FID flame ionization detector), and internal/external standard quantification. The standard also specifies system-suitability requirements (e.g., resolution between adjacent components) and result reporting (each fatty acid as a mass fraction of total fatty acids, or a specific fatty acid content).
⚠️ GC quantification is sensitive to injection consistency and column efficiency: inject a standard mixture in each batch to verify retention times and response factors, and periodically check resolution to avoid misidentification of interfering peaks.
5. Engineering Practice 🛠️
- 🔍 Feed formulation monitoring: compare the formulated recipe with measured fatty acid composition to verify oil addition accuracy.
- 🔧 Raw material acceptance: perform fatty acid fingerprinting on oil raw materials (soybean oil, fish oil, etc.) to detect adulteration.
- 📊 Quality control: use reference and control samples to monitor between-batch repeatability and enable inter-laboratory comparison.
- 📋 Regulatory compliance: provide analytical data supporting label claims and additive limits for animal-derived feeds.
6. Frequently Asked Questions ❓
❓ Q: Why a “TS” rather than a formal EN standard?
A: At the time the method still required validation through European collaborative trials, so it was issued as a Technical Specification (TS) and DD draft to gather application experience during a transition period.
A: At the time the method still required validation through European collaborative trials, so it was issued as a Technical Specification (TS) and DD draft to gather application experience during a transition period.
❓ Q: Can a non-polar column replace a polar column for FAME analysis?
A: Polar columns better separate FAME by degree of unsaturation (especially cis/trans isomers); non-polar columns separate by chain length. Choose the stationary phase per 17764-2 and verify resolution.
A: Polar columns better separate FAME by degree of unsaturation (especially cis/trans isomers); non-polar columns separate by chain length. Choose the stationary phase per 17764-2 and verify resolution.
❓ Q: Does high sample moisture affect results?
A: Yes. Moisture interferes with extraction and methylation efficiency; the specification requires samples to be prepared as prescribed (e.g., well mixed, dried if necessary) for repeatable results.
A: Yes. Moisture interferes with extraction and methylation efficiency; the specification requires samples to be prepared as prescribed (e.g., well mixed, dried if necessary) for repeatable results.
🔍 Q: How are results reported?
A: Usually as area normalization of each methyl ester as a mass fraction of total fatty acids, or internal-standard quantification, reporting mass fraction (g/100 g) and stating the preparation and chromatographic conditions used.
A: Usually as area normalization of each methyl ester as a mass fraction of total fatty acids, or internal-standard quantification, reporting mass fraction (g/100 g) and stating the preparation and chromatographic conditions used.