Overview - ISO 22195-2:2023 (Turmeric)
ISO 22195-2:2023 is an international test method for identifying and quantifying the index ingredient of turmeric (curcumin) in coloured textiles. Part of the ISO 22195 series on natural colourants, this standard specifies sample preparation, extraction, instrumental analysis (LC‑MS or GC‑MS) and calculation/reporting requirements to determine whether a fabric has been coloured using turmeric-derived dyes.
Key topics and technical requirements
- Scope: Detection and quantification of the turmeric index compound curcumin in dyed or printed textiles.
- Sample preparation: Cut specimen to ~5 mm × 5 mm pieces (~1 g), extract with methanol (10 ml) in a capped borosilicate container using an ultrasonic bath (30 ± 2 °C for 20 ± 1 min), cool, dilute if needed and filter (0.2 µm) into analysis vials.
- Reagents & apparatus: HPLC‑grade solvents (methanol, acetonitrile), formic acid, curcumin reference standard, analytical balance (0.001 g), ultrasonic bath, LC‑MS (ESI) and/or GC‑MS. ISO 3696 (water quality) is referenced for laboratory water.
- Instrumentation & chromatography: Detection/qualification by LC‑MS (ESI+), HPLC‑DAD (430 nm) or GC‑MS. Annex A provides example chromatographic conditions and chromatograms for turmeric extracts and dyed fabrics.
- Calibration & quantification: Calibration standards typically at 1, 10, 20, 50, 100 mg/L (minimum 5 points). For quantification a high linearity is required (correlation coefficient > 0.995; R > 0.990 allowed).
- Calculation: Convert measured solution concentration to mg/kg in textile using the formula:
C = (Cs × f × V) / W
where C = curcumin concentration in mg/kg, Cs = solution concentration in mg/L, f = dilution factor, V = extraction volume (mL), W = specimen mass (g).
- Reporting: Must reference ISO 22195-2:2023 and include specimen ID, curcumin concentration (mg/kg), chromatographic conditions, any deviations, and test date.
- Caveat: Detection of curcumin indicates presence of the index compound but does not alone prove the textile was dyed exclusively with turmeric.
Applications and users
- Textile testing laboratories performing natural dye identification, quality control and compliance checks.
- Manufacturers and brands verifying “natural-dyed” claims.
- Regulatory bodies and forensic analysts investigating provenance or contamination of coloured fabrics.
- Conservation scientists, researchers and dye chemists studying historical or artisanal textiles.
Related standards
- ISO 22195 series (other parts listable on the ISO website)
- ISO 3696 - Water for analytical laboratory use
Keywords: ISO 22195-2:2023, turmeric, curcumin, textiles, natural colourant, LC‑MS, GC‑MS, extraction, calibration curve, test method.
Open preview (PDF)Textiles — Determination of index ingredient from coloured textile — Part 2: Turmeric
