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.
