Overview
ISO 3137:1974 - "Anhydrous hydrogen fluoride for industrial use - Sampling" specifies standardized methods for taking laboratory samples of anhydrous hydrogen fluoride (HF) and for preparing test samples for subsequent analysis (notably water content). The standard covers safe handling, the sampling principle, required apparatus and step-by-step procedures for: (1) collecting a laboratory sample from road/rail tanks, drums or cylinders, and (2) preparing a test sample in a polyolefin vessel with ice. This document has also been approved by IUPAC.
Key topics and technical requirements
- Scope & applicability
- Sampling from bulk containers: road and rail tanks, drums and cylinders.
- Preparation of test samples for water-content and other determinations.
- Safety warnings
- HF is highly corrosive, boils at 19.5 °C, attacks glass, and produces toxic/irritant vapour.
- Mandatory use of a well‑ventilated fume cupboard, full head/face protection, rubber gloves, boots and gown. In case of contact: flood with water and seek immediate medical attention.
- Sampling principle
- Allow liquid HF to flow into one or more cooled, evacuated stainless‑steel cylinders with a total capacity of at least 1 kg.
- Apparatus & key components
- Stainless steel sample cylinder(s), coupling tubes, stainless steel valves and unions.
- Vacuum pump capable of rapidly producing about 0.6 kPa for evacuation.
- Cooling to below 15 °C during evacuation/filling.
- Cleaning/drying: parts washed, dried in an oven at ~110 °C for 8–12 hours and stored in oven until use.
- Test-sample preparation
- Transfer HF into a polyolefin dilution vessel containing two layers of crushed ice (approx. 40 g each) using a polyolefin delivery tube and copper connecting tube.
- Calculate concentration by mass: concentration (%) = m1 / (m1 + m2) × 100, where m1 = mass of HF introduced, m2 = mass of ice.
- Procedural controls
- Purging, controlled valve sequencing, and careful weighing to the nearest 0.1 g are specified.
Applications and users
- Organizations that handle, transport or analyze industrial HF:
- Chemical manufacturers and processors
- Transport and logistics companies (road/rail tank operators)
- Analytical and quality‑control laboratories determining water or impurity contents
- Safety, compliance and regulatory teams implementing sampling protocols
- Practical uses:
- Producing representative laboratory samples for Karl Fischer or other water analyses
- Ensuring safe, repeatable sampling for QA/QC and regulatory compliance
Related standards
- ISO 3138 - Determination of non‑volatile acid content (titrimetric)
- ISO 3699 - Determination of water content (Karl Fischer)
- ISO 3700 - Determination of water content (conductimetric)
- ISO 3701 - Determination of fluorosilicic acid content
- ISO 3702 - Determination of sulfur dioxide content
- ISO 3139 - Sampling and methods of test for aqueous hydrofluoric acid
Keywords: ISO 3137:1974, anhydrous hydrogen fluoride, HF sampling, laboratory sampling, sample preparation, polyolefin vessel, stainless steel cylinder, HF safety, water content analysis.
