ISO 16050:2003

Overview

ISO 16050:2003 specifies a validated analytical method for the determination of aflatoxin B1 and the total content of aflatoxins B1, B2, G1 and G2 in cereals, nuts and derived products. The method uses reverse‑phase high‑performance liquid chromatography (HPLC) with immunoaffinity (IA) column clean‑up and post‑column derivatization. The limit of quantification (LOQ) is 8 µg/kg for aflatoxin B1 and for the sum of B1, B2, G1 and G2. The procedure has been validated for maize, peanut butter and raw peanuts and is applicable to oilseed products, dried fruits and related matrices.

Key topics and technical requirements

• Analytical principle: extraction with methanol/water, IA column affinity purification, HPLC separation with fluorescence detection after post‑column derivatization.
• Clean‑up: use of immunoaffinity columns containing antibodies specific to aflatoxins B1, B2, G1 and G2; IA columns must have a minimum binding capacity (≥100 ng AFB1) and stipulated recovery performance (≥80% for B1, B2, G1; ≥60% for G2).
• Chromatography: reverse‑phase column (example C18, 250 × 4.6 mm, 5 µm) and post‑column reactor; fluorescence detection (excitation ~365 nm, emission ~435 nm) capable of detecting ≥0.05 ng AFB1 per injection (50 µl injection typical).
• Reagents and solvents: HPLC‑grade acetonitrile, methanol, extraction solvent (7:3 methanol:water), mobile phase formulation and post‑column derivatization reagents (iodine or pyridinium hydrobromide perbromide).
• Validation and performance: LOQ = 8 µg/kg; validated sample concentrations reported for maize (24.5 µg/kg total), peanut butter (8.4 µg/kg total) and raw peanuts (16 µg/kg total).
• Quality and safety: use acid‑washed glassware to prevent losses; aflatoxins are carcinogenic-protect samples from light and handle volatile solvents (e.g., toluene) in a fume hood.

Applications and who uses it

• Food testing laboratories performing routine mycotoxin analysis and regulatory compliance testing for cereals, nuts and derived products.
• Government and public‑health agencies enforcing maximum levels for aflatoxins in food.
• Food manufacturers, processors and QA/QC teams in the grain, peanut and dried‑fruit industries assessing raw materials and finished products.
• Research laboratories developing or comparing analytical methods for aflatoxin monitoring and method validation.

Related standards

• ISO 3696:1987 - Water for analytical laboratory use (referenced for reagent water quality).
• Based on EN 12955:1999 (CEN/TC 275) - provides the European method background.

Keywords: ISO 16050:2003, aflatoxin B1, aflatoxins B2 G1 G2, HPLC, immunoaffinity column, post‑column derivatization, cereals, nuts, mycotoxin analysis, food safety.