ISO 10519:2015

Overview

ISO 10519:2015 specifies a laboratory spectrometric method for the determination of chlorophyll content in rapeseed (expressed as mg/kg chlorophyll a). The method covers sample preparation, extraction, spectrometric measurement and calculation of results. It is explicitly not applicable to chlorophyll determination in oils. ISO 10519:2015 is intended for routine quality control, research and inter‑laboratory comparability for oilseed/rapeseed material.

Key topics and technical requirements

• Principle: solvent extraction of ground rapeseed followed by absorbance measurement and baseline correction.
• Sample preparation:
  • Reduce laboratory sample to test sample per ISO 664.
  • If moisture > 10% (m/m), dry for 12 h at 45 °C to protect chlorophyll.
  • Grind ~50 g to a uniform sample; use 2 g test portions for extraction.
• Extraction solvent:
  • Use anhydrous solvent mix (example given: 100 ml anhydrous ethanol + 300 ml anhydrous iso‑octane or anhydrous n‑heptane or anhydrous petroleum ether).
  • Add 30 ml solvent to 2 g test portion.
• Apparatus:
  • Mechanical grinder or microgrinder/ball mill (stainless tubes, Ø16 mm balls, 240 min⁻¹ horizontal shake or commercial ball mill).
  • Spectrometer capable of absorbance 600–700 nm, spectral bandwidth ~2 nm; optical cell path length ≥ 1 cm.
• Measurement:
  • Measure absorbance at 665 nm, 705 nm and 625 nm.
  • Corrected absorbance: A_corr = A665 − (A705 + A625)/2.
  • Calculation: w (mg/kg) = (k × A_corr × V) / (l × m) with k = 13; V = solvent volume (mL); l = cell path length (cm); m = test portion mass (g).
• Precision:
  • Repeatability: difference between two results in same lab should not exceed 10% of mean.
  • Reproducibility: difference between labs should not exceed 20% of mean.
• Reporting: include method, sampling reference, test results, any deviations, moisture basis if reporting dry‑product values.

Applications and users

• Quality control laboratories in seed processing, oilseed trading and agronomy.
• Plant breeding and research groups monitoring chlorophyll content for varietal assessment or harvest timing.
• Inspection bodies verifying rapeseed quality for trade specifications.
• R&D teams developing extraction or spectrometric methods for oilseeds (note: method excludes oils).

Related standards

• ISO 664 (reduction of laboratory sample to test sample)
• ISO 665 (moisture determination for oilseeds)
• ISO 648 (pipettes)
• ISO 542 (sampling recommendations)
• ISO 5725 (precision assessment methodology)

Keywords: ISO 10519:2015, rapeseed chlorophyll, chlorophyll determination, spectrometric method, oilseeds, extraction solvent, absorbance 665 nm.