ISO 10337-1997 PDF

Full title and description

ISO 10337:1997 — Crude petroleum — Determination of water — Coulometric Karl Fischer titration method. This International Standard specifies a coulometric Karl Fischer titration procedure for the direct determination of water in crude petroleum, including requirements for sampling, apparatus, reagents, test procedure, calculation and reporting.

Abstract

ISO 10337:1997 describes a laboratory method using coulometrically generated iodine (Karl Fischer coulometric titration) to quantify water in crude oil. The standard covers sample handling, apparatus and reagent requirements, test portion preparation, interference limits (notably mercaptans and ionic sulfides), performance characteristics and quality control/precision statements; it also includes a normative annex on sample handling and an informative annex describing an alternative volumetric test‑portion measurement.

General information

• Status: Published — International Standard (confirmed in periodic reviews; listed as current by ISO).
• Publication date: First edition, December 1997 (15 December 1997 is given in the edition metadata).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 75.040 — Crude petroleum.
• Edition / version: Edition 1 (1997).
• Number of pages: 12 (ISO listing; some national-adoption documents show small pagination differences).

Scope

Specifies a coulometric Karl Fischer titration method for the direct determination of water content in crude petroleum. The method is intended for routine laboratory use and gives guidance on sampling and sample preparation, apparatus and reagents, test procedure, checks and blank corrections, calculation of results and expression of water content (m/m). The standard notes the effect of interfering sulfur species (mercaptans and ionic sulfides) on low-level determinations and provides measurement-range guidance and precision data. Annex A (normative) covers sample handling and Annex B (informative) describes an alternative volumetric test‑portion measurement.

Key topics and requirements

• Principle: coulometric generation of iodine; water amount calculated from integrated charge according to Faraday’s law.
• Measurement ranges and interference limits: method covers water contents from roughly 0.02 % to 5.00 % (m/m) with specified more restrictive ranges when mercaptan/sulfide sulfur is present — precision and applicability statements are given in the standard.
• Apparatus and reagents: automatic coulometric Karl Fischer titrator, appropriate solvent/carrier and KF reagents, mixers/dispensers, syringes, balance and temperature control as specified.
• Sampling and sample handling: follows good crude-oil sampling practice (references to accepted sampling standards and guidance are included); homogenization, temperature recording and handling to avoid water loss or ingress are required.
• Quality control: routine check injections, reagent response checks, blank/background monitoring, and criteria for replacing electrolytes or troubleshooting unstable backgrounds.
• Calculation and reporting: conversion of titrator microgram display and test‑portion mass to percent mass fraction (m/m); reporting format and required test report items are specified.
• Precision: repeatability and reproducibility data are provided for representative concentration levels.

Typical use and users

Used by petroleum and refinery laboratories, quality control and product testing facilities, crude-oil purchasers/sellers and custody-transfer laboratories, and research laboratories needing reliable water-content determination in crude oils. The method supports refining decisions, trade/specification compliance and process control.

Related standards

Commonly used alongside sampling standards and other water-determination methods. Relevant standards and methods frequently referenced with ISO 10337 include ISO 3170/3171 (sampling of crude oil), and widely used Karl Fischer methods and industry test methods such as ASTM D4928, ASTM D6304 and related IP methods for water in crude petroleum and petroleum products. Laboratories often select between ISO 10337 and applicable ASTM/IP methods based on regional practice, scope and instrument configuration.

Keywords

ISO 10337, crude petroleum, water determination, Karl Fischer, coulometric titration, sample handling, mercaptans, sulfur interference, precision, laboratory method.

FAQ

Q: What is this standard?

A: ISO 10337:1997 is an ISO International Standard that specifies a coulometric Karl Fischer titration method for determining water content in crude petroleum.

Q: What does it cover?

A: It covers the principle, apparatus and reagent requirements, sampling and sample preparation guidance, the titration procedure, checks and quality control, calculation of results, precision data and reporting requirements, plus normative and informative annexes on sample handling and an alternative volumetric test‑portion measurement.

Q: Who typically uses it?

A: Petroleum and refinery QC laboratories, custody-transfer and trading laboratories, instrument manufacturers and test houses that perform water determinations in crude oil.

Q: Is it current or superseded?

A: ISO’s publication record shows ISO 10337:1997 as a first-edition (1997) International Standard that has been subject to periodic review and listed as confirmed/current in ISO’s lifecycle updates; it is not listed as withdrawn or superseded. Users should always confirm the current status with their national standards body or ISO before application.

Q: Is it part of a series?

A: It is maintained under ISO/TC 28/SC 2 (measurement of petroleum and related products) and is used alongside other petroleum testing standards (including regional/industry methods such as ASTM and IP Karl Fischer methods).

Q: What are the key keywords?

A: Crude petroleum; water determination; Karl Fischer; coulometric titration; sample handling; mercaptans; sulfur interference; precision; ISO 10337:1997.