Overview
ISO 22863-8:2021 specifies a laboratory test method for determining arsenic content in pyrotechnic compositions (fireworks) using hydride generation - atomic fluorescence spectrometry (HG-AFS). The standard describes sample pre‑treatment, reagents, apparatus, instrument settings, calculation procedures and reporting requirements to obtain quantitative arsenic results from digested fireworks samples.
Key topics and requirements
- Scope: Quantitative determination of arsenic in pyrotechnic compositions by HG‑AFS.
- Principle: Dissolve the sample by acidic digestion, reduce pentavalent arsenic to As(III) (thiourea/ascorbic acid), generate volatile AsH3 with potassium borohydride, transport by argon to an atomizer and measure fluorescence from an arsenic hollow‑cathode lamp. Fluorescence intensity is proportional to arsenic concentration.
- Sample preparation: Typical sample mass 0.2 g (ground and sieved), digested with nitric and perchloric acids (heated to ~210 °C), evaporated and diluted to final volume with nitric acid and thiourea/ascorbic acid solution.
- Reagents & standards: Perchloric acid, nitric acid, thiourea, ascorbic acid, potassium borohydride, NaOH, and calibrated arsenic standard solutions for a 0–10 µg/L working curve.
- Instrumentation: Atomic fluorescence photometer with arsenic hollow‑cathode lamp and hydride generation accessory. Example operating conditions are provided (e.g., lamp current ≈ 60 mA, carrier gas ~500 mL/min, shielding flow ~1 000 mL/min).
- Calibration & calculations: Standard-curve method for routine tests; Annex A provides a standard addition procedure to compensate matrix effects. Formulae are given to convert measured solution concentrations to mg/kg in the sample.
- Performance & limits: Repeatability: absolute difference between two repeat determinations should not exceed 20% of the mean (improved to 10% using Annex A). For a 0.2 g sample diluted to 50 mL the standard reports LOD ≈ 0.01 mg/kg and LOQ ≈ 0.3 mg/kg.
- Reporting: Test report must identify laboratory, sample description (per ISO 22863‑1), results, anomalies and reference ISO 22863‑8:2021.
Applications and users
- Laboratories performing fireworks testing, quality control and compliance testing for manufacturers of pyrotechnic products.
- Regulatory and market surveillance bodies checking arsenic limits in consumer fireworks and professional pyrotechnics.
- Environmental and forensic labs analyzing pyrotechnic residues for safety investigations.
- Certification and conformity assessment providers validating composition relative to national or regional restrictions.
Related standards
- ISO 22863-1 - General requirements and terms for test methods in the ISO 22863 fireworks series. ISO 22863‑8 is part of the broader ISO 22863 series covering specific chemical determinations in pyrotechnics.
Keywords: ISO 22863-8, arsenic content, hydride generation atomic fluorescence spectrometry, HG‑AFS, fireworks testing, pyrotechnic compositions, arsenic analysis, standard addition, LOD, LOQ.