ISO 8754:2003

Overview

ISO 8754:2003 - Petroleum products: Determination of sulfur content by energy-dispersive X‑ray fluorescence (EDXRF) specifies a standardized analytical method for measuring sulfur in a wide range of petroleum products (naphthas, unleaded gasolines, middle distillates, residual fuel oils, base lubricating oils and components). The method applies to samples with sulfur contents from 0.03 % (m/m) to 5.00 % (m/m) and describes instrument requirements, calibration, sample preparation, measurement and reporting.

Key topics and technical requirements

• Analytical principle: Energy‑dispersive X‑ray fluorescence spectrometry (EDXRF). A test portion is excited by X‑rays and sulfur Kα radiation is measured and compared to a calibration curve.
• Scope and limits: Applicable sulfur range 0.03–5.00 % (m/m); lower‑level procedures for automotive fuels (<0.20 % m/m) are noted as under development.
• Instrument requirements: X‑ray source with significant flux above 2.5 keV, detector sensitive at ~2.3 keV, removable sample cup (≥3 mm depth) with X‑ray transparent film, filters for sulfur discrimination, pulse counting and pulse‑height analysis electronics.
• Calibration: Use certified reference materials or primary standards prepared by dissolving known sulfur compounds (e.g., dibenzothiophene, dibutylsulfide, benzothiophene) in low‑sulfur white oil. Calibration ranges and standard concentrations are specified; routine short‑ and long‑term checks are required.
• Sample handling: Follow ISO 3170/3171 sampling standards; homogenize viscous samples and avoid window bowing for volatile samples. Use fresh sample cups/films; avoid re‑using disposable cups.
• Interferences: Heavy metal additives (e.g., lead alkyls) and elements such as Si, P, Ca, O, K, Zn, Mo, Ba and halogens can interfere when present above a few hundred mg/kg. Matrix effects (C/H ratio) may also affect results.
• Reporting and precision: Results reported to 0.001 % for 0.030–0.099 % and to 0.01 % for 0.10–5.00 %. Precision data (repeatability and reproducibility) are given in the standard (derived per ISO 4259).

Applications and users

• Quality control in refineries, fuel distribution and lubricant production
• Environmental and regulatory testing for sulfur limits in fuels
• Independent analytical and commercial testing laboratories
• Instrument manufacturers and method validation teams implementing EDXRF workflows

Safety and compliance

• The standard warns about hazardous materials and radiation safety. Users must comply with local regulations when instruments contain radioactive sources and ensure trained personnel perform source handling.

Related standards

• Normative references: ISO 3170 and ISO 3171 (sampling of petroleum liquids)
• Precision and data application referenced to ISO 4259
• Prepared by ISO/TC 28 (Petroleum products and lubricants)

Keywords: ISO 8754:2003, sulfur content, petroleum products, energy‑dispersive X‑ray fluorescence, EDXRF, sulfur determination, calibration, fuel quality.