ISO 11024-2:1998

Overview

ISO 11024-2:1998 provides general guidance on the utilization of chromatographic profiles for samples of essential oils. It describes how to determine whether a sample’s gas chromatography (GC) profile conforms to the reference chromatographic profile for a given essential oil. The standard covers instrumentation, sample preparation, identification and quantification of representative and characteristic constituents, and reporting of results.

Key topics and technical requirements

• Scope and purpose: Defines procedures to compare a sample chromatogram with the reference chromatographic profile included in the oil-specific standard.
• Apparatus: Requires a gas chromatograph with a capillary column, split injector and flame ionization detector (FID), plus a data processing system (integrator/computer) in accordance with ISO 7609.
• Sample preparation: Refers to ISO 356 for recommended sample-preparation methods to produce test solutions for GC analysis.
• System performance check: Specifies a prescribed test mixture (e.g., n-hexanol, α-pinene, 1,8-cineole, linalool, linalyl acetate, eugenol, β-caryophyllene, benzyl salicylate, etc.) and acceptable percentage-area ranges. Performance acceptance requires target ranges and, for low-level peaks (e.g., n‑decanal), a signal-to-noise ratio greater than 100.
• Identification methods: Locating representative and characteristic peaks may use chromatogram-type comparison, retention indices, spiking (standard additions), or GC–MS coupling.
• Quantification: Uses surface-area normalization (relative percent area) following ISO 7609 to verify concentrations and concentration ratios against limits in the oil-specific profile.
• Reporting: Test reports must document methods, operational details not specified in the standard, observed results, and full sample identification.

Applications and practical value

• Quality control and conformity testing: Verify that commercial batches match the chromatographic profile for identity and composition.
• Authenticity and adulteration screening: Detect missing or out-of-range representative/characteristic constituents that may indicate adulteration or substitution.
• Batch consistency and supplier qualification: Confirm consistency across lots and suppliers by comparing GC profiles to reference limits.
• Method verification: Use the standard’s test mixture and acceptance criteria to validate GC system performance for essential oil analysis.

Who should use it

• Analytical chemists in essential oil manufacturing and flavor/fragrance industries
• Quality assurance and regulatory laboratories
• Standards bodies and auditors performing conformity assessments
• Contract testing laboratories offering GC profiling services

Related standards

• ISO 11024-1 - Elaboration of chromatographic profiles for presentation in standards
• ISO 356 - Sample preparation for essential oil testing
• ISO 7609 - General method for capillary-column gas chromatography of essential oils

Keywords: ISO 11024-2, essential oils, chromatographic profiles, gas chromatography (GC), GC-FID, quality control, chromatogram, representative constituents, characteristic constituents.