ISO 22863-9:2021

Overview

ISO 22863-9:2021 defines a laboratory test method for determining mercury content in pyrotechnic compositions (fireworks) using hydride generation atomic fluorescence spectrometry (HG-AFS). The standard specifies sample pre-treatment, digestion (aqua regia), reagent and apparatus requirements, instrumental conditions, calculation procedures and reporting. It is Part 9 of the ISO 22863 series on test methods for specific chemical substances in fireworks.

Key topics and technical requirements

• Scope: Quantitative determination of mercury in fireworks/pyrotechnic samples by HG‑AFS.
• Sample preparation: Crush and sieve (80 mesh), typical sample mass 0.2 g (Annex A uses 0.5 g for standard addition), digestion in boiling water bath with a hydrochloric/nitric acid mixed reagent (aqua regia), dilution to defined volume (commonly 100 ml).
• Reagents (examples): hydrochloric acid, nitric acid, potassium dichromate, sodium hydroxide, potassium borohydride (reducing agent), and traceable mercury standard solutions for calibration.
• Instrumentation: Atomic fluorescence photometer equipped with a mercury hollow cathode lamp, carrier gas (argon) for transporting generated mercury vapor, and optimized settings (lamp current, carrier gas flow, reading mode).
• Analytical principle: In acidic medium mercury is reduced (by potassium borohydride) to elemental mercury vapor which, under excitation from a mercury hollow cathode lamp, emits fluorescence proportional to mercury concentration; measurement against a standard calibration curve.
• Quality and performance:
  • Repeatability: absolute difference between two independent determinations under repeatability conditions ≤ 20% of the mean.
  • Detection limit (for 0.2 g sample / 100 ml): 0.03 mg/kg; limit of quantification: 0.09 mg/kg.
  • Instrument blank stability: repeated blank readings should vary by ≤ 5 (instrument-specific unit).
• Accuracy improvement: Annex A describes the standard addition method to reduce matrix effects and improve accuracy (repeatability requirement ≤ 10% when using this method).
• Reporting: Test report must identify the laboratory, sample, reference to ISO 22863-9:2021, results, and any anomalies.

Applications and users

• Routine quality control and safety testing by fireworks and pyrotechnic manufacturers.
• Accredited testing laboratories performing chemical compliance testing for regulatory limits on mercury in consumer pyrotechnics.
• Regulatory bodies, customs and import authorities verifying conformity and environmental safety.
• Research organizations studying toxic metal content in pyrotechnic emissions and residues.

Related standards

• ISO 22863-1 (General): terms, sampling and general requirements for the ISO 22863 series.
• Other parts of ISO 22863 addressing additional specific hazardous substances and test methods in fireworks.

Keywords: ISO 22863-9:2021, mercury content, hydride generation atomic fluorescence spectrometry, HG‑AFS, fireworks testing, pyrotechnic compositions, mercury detection limit, standard addition method.