HYDROFLUORIC ACID ANALPURE®

Significance of the topic

Hydrofluoric acid is a versatile and powerful reagent with applications ranging from glass etching and metal cleaning to semiconductor manufacturing. Its performance and safety depend critically on chemical purity and controlled concentration, making detailed quality assessment essential for both industrial and research settings.

Study objectives and overview

The primary aim of this analysis was to confirm that a 50 % w/w hydrofluoric acid batch (Batch no. 4023) meets stringent purity specifications. The evaluation covered visual appearance, major anions and cations, elemental assay, and an extensive panel of trace impurities to ensure compliance with internal and pharmacopeial standards.

Methodology and instrumentation

Key analytical approaches included:

• Colour evaluation using APHA/Hazen standards.
• Quantitative acid assay by titrimetric determination of fluoride concentration.
• Anion and cation impurity screening via ion chromatography.
• Trace metal quantification by inductively coupled plasma mass spectrometry (ICP-MS), achieving sub-ppb detection limits.

Main results and discussion

All measured parameters fell within specified limits:

• Colour: less than 10 APHA units, indicating negligible organic coloration.
• Major impurities: fluorosilicic acid <20 ppm, chloride <4 ppm, total sulphur <0.1 ppm, total phosphorus <0.05 ppm.
• Assay: 50 % w/w hydrofluoric acid, confirming target concentration.
• Trace elements: each of over 60 monitored metals (including Al, Ca, Fe, Na, Zn) remained below maximum allowable concentrations, with most values <0.1 ppb.

Potential slight increases in Ca, Na, Fe, Al, or Zn upon long-term storage in polyethylene containers were noted but did not affect current compliance.

Benefits and practical applications

The demonstrated high purity and consistent assay of this hydrofluoric acid make it suitable for sensitive processes such as semiconductor wafer cleaning, precision glass etching, and analytical standards. Reliable impurity control minimizes equipment corrosion, sample contamination, and downstream processing failures.

Future trends and applications

Advancements are expected in real-time monitoring through miniaturized spectroscopic and electrochemical sensors. Coupling inline analytical platforms with process control systems will enable dynamic purity tracking. Additionally, speciation studies of fluorosilicate complexes may offer deeper insight into acid behaviour in industrial applications.

Conclusion

Batch 4023 of 50 % hydrofluoric acid fully complies with specified quality criteria. The comprehensive analysis confirms its readiness for deployment in high-precision and critical industrial processes.