ISO 22195-1:2023

Overview

ISO 22195-1:2023 - Textiles - Determination of index ingredient from coloured textile - Part 1: Madder specifies a laboratory test method to detect and quantify the index ingredient alizarin from textiles dyed with madder (Rubia spp.). The standard covers sample preparation, extraction, chromatographic analysis (LC‑MS or GC‑MS), calibration and calculation of alizarin concentration reported in mg/kg. The second edition (2023) updates the extraction solvent to a single organic solvent (methanol) and adds a GC‑MS analysis option alongside LC‑MS.

Key topics and technical requirements

• Scope: Identification and quantification of alizarin as the index marker for madder-dyed textiles. Detection of alizarin alone does not by itself prove exclusive use of madder (see note in principle).
• Reagents: HPLC-grade water (ISO 3696), methanol (extraction solvent), acetonitrile, formic acid (30% v/v), and a certified alizarin reference standard (≥95% purity recommended).
• Apparatus: Analytical balance (0.001 g resolution), ultrasonic bath (30 ± 2 °C), 50 ml borosilicate containers, 0.2 µm membrane filters, LC‑MS (ESI) and/or GC‑MS instruments.
• Procedure (high level):
  • Cut test specimen (~1 g, ~5×5 mm pieces), weigh, add 10 ml methanol.
  • Ultrasonic extraction for 20 ± 1 min at 30 ± 2 °C, cool and dilute if required.
  • Filter extract (0.2 µm) into vial and analyze by LC‑MS or GC‑MS.
• Calibration & quantification: Calibration points typically 1, 10, 20, 50 and 100 mg/L (laboratory-specific ranges allowed). For reliable quantification, correlation coefficient targets are specified (calibration fit R typically >0.995; R > 0.990 noted). Calculation converts solution concentration to mg/kg using the sample mass, extraction volume and dilution factor (standard formula provided).
• Reporting: Test report must reference ISO 22195-1:2023, identify specimen, give alizarin concentration (mg/kg), chromatographic conditions, deviations and test date.

Applications and users

ISO 22195-1:2023 is used by:

• Textile testing and quality control laboratories for verifying natural dye usage.
• Cultural heritage and conservation scientists analyzing historical textiles for madder dyes.
• Manufacturers and suppliers validating natural-dye claims on fabrics.
• Regulatory and forensic laboratories investigating provenance or authenticity of coloured textiles.

Practical applications include dye authentication, supply‑chain verification, conservation diagnostics, and research into natural colourants.

Related standards

• ISO 3696 - Water for analytical laboratory use (referenced for reagent quality).
• Other parts of the ISO 22195 series (see ISO website for the full set).

Keywords: ISO 22195-1:2023, madder, alizarin, textiles, natural colourant, LC‑MS, GC‑MS, HPLC, chromatographic analysis, index ingredient, extraction, calibration curve.