IEC 62321-7-2-2017 PDF

Full title and description

Determination of certain substances in electrotechnical products — Part 7-2: Hexavalent chromium — Determination of hexavalent chromium (Cr(VI)) in polymers and electronics by the colorimetric method. This part of the IEC 62321 series specifies extraction procedures (organic solvent swelling/dissolution followed by alkaline digestion or toluene/alkaline digestion for insoluble samples) and a colorimetric determination using 1,5-diphenylcarbazide with spectrophotometric measurement (540 nm) to quantify Cr(VI) in polymeric and electronic materials.

Abstract

IEC 62321-7-2:2017 provides a validated laboratory method for quantitative measurement of hexavalent chromium in polymers and electronic components. The method covers sample dissolution or swelling in suitable organic solvents, alkaline extraction or digestion to release Cr(VI), reaction with 1,5-diphenylcarbazide under acidic conditions to form a coloured complex, and spectrophotometric measurement at 540 nm. The procedure includes calibration, precision/LOD/LOQ guidance, quality assurance (including matrix spike recovery), and reporting requirements for test laboratories performing compliance or investigative testing.

General information

• Status: Current / Active (published part of the IEC 62321 series; horizontal environment standard).
• Publication date: 28 March 2017 (IEC publication date; national adoptions commonly dated mid‑2017).
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 31.020; 71.040.50 (physicochemical methods of analysis / electronic components).
• Edition / version: Edition 1.0 (2017).
• Number of pages: 35 pages (IEC publication metadata).

Scope

Specifies a laboratory method for the quantitative determination of hexavalent chromium in soluble polymers (e.g., ABS, PC, PVC) and in insoluble/unknown polymers and electronic materials that do not contain interfering antimony compounds. It covers sample preparation (dissolution/swelling or high‑temperature toluene/alkaline digestion for insoluble samples), extraction, colour‑forming reaction with 1,5‑diphenylcarbazide, spectrophotometric measurement at 540 nm, calibration approaches, limits of detection and quantification, precision, and quality control measures required for reliable reporting. The method is intended for use by testing laboratories supporting regulatory compliance and materials assessment.

Key topics and requirements

• Sample types addressed: soluble polymers (ABS, PC, PVC) and insoluble/unknown polymers and electronic materials (without antimony interference).
• Extraction approaches: organic solvent to dissolve or swell matrix; alkaline extraction for Cr(VI); for insoluble matrices a toluene/alkaline digestion at elevated temperature (~150–160 °C) is specified.
• Analytical chemistry: colorimetric reaction of Cr(VI) with 1,5-diphenylcarbazide under acidic conditions producing a red‑violet complex measured at 540 nm.
• Calibration and instrumentation: procedures for instrument calibration (permanent and traditional calibration approaches) and calculation of results.
• Quality assurance: precision testing, matrix spike recovery correction, procedures to determine LOD and LOQ, and test report requirements.
• Limitations and interferences: attention to matrices containing antimony or other interfering species; method notes on minimizing redox changes (Cr(VI) ↔ Cr(III)) during extraction.

Typical use and users

Used by accredited analytical laboratories, product compliance and quality teams, environmental and materials engineers, and regulatory bodies for RoHS/REACH‑related assessments and internal material control. Typical applications include pre‑compliance screening, failure investigation, supplier verification, and formal regulatory testing where hexavalent chromium content in polymeric parts and electronic assemblies must be quantified.

Related standards

Part of the IEC 62321 series; related parts include IEC 62321-1 (general aspects), IEC 62321-2, IEC 62321-3-x, IEC 62321-4, IEC 62321-5, IEC 62321-6, IEC 62321-7-1 (Cr(VI) in coatings), IEC 62321-8 (phthalates), IEC 62321-9, and other method parts addressing specific restricted substances and analytical techniques. It is also harmonized/implemented in regional standards (EN adoptions) used for regulatory and conformity purposes.

Keywords

hexavalent chromium; Cr(VI); colorimetric method; 1,5-diphenylcarbazide; polymers; electronics; alkaline extraction; toluene digestion; spectrophotometry (540 nm); IEC 62321; RoHS testing; LOD/LOQ; matrix spike recovery.

FAQ

Q: What is this standard?

A: IEC 62321-7-2:2017 is the IEC method for quantitative determination of hexavalent chromium (Cr(VI)) in polymers and electronic materials using a colourimetric (1,5‑diphenylcarbazide) assay following solvent/alkaline extraction or digestion.

Q: What does it cover?

A: It covers sample preparation (dissolve/swelling or high‑temperature toluene/alkaline digestion), extraction of Cr(VI), formation of a coloured complex with 1,5‑diphenylcarbazide, spectrophotometric measurement at 540 nm, calibration, determination of LOD/LOQ, precision and QA/QC, and reporting. Limitations for samples containing interfering species (e.g., antimony) are addressed.

Q: Who typically uses it?

A: Accredited test laboratories, product compliance teams, electronics and polymer manufacturers, environmental testing labs, and regulators checking materials for restricted Cr(VI) content.

Q: Is it current or superseded?

A: IEC 62321-7-2:2017 is the published edition (Edition 1.0, 2017) and is in current use as part of the IEC 62321 suite; national/adopted versions (EN/BS/etc.) were issued in 2017. Check with the IEC or national standards body for any amendments or later revisions beyond the 2017 edition.

Q: Is it part of a series?

A: Yes — it is one part of the IEC 62321 series (methods for determination of certain substances in electrotechnical products). Other parts address different substances and techniques (e.g., halogens, phthalates, HBCDD, metal coatings). Laboratories normally use multiple parts of the series to cover a full materials‑compliance program.

Q: What are the key keywords?

A: hexavalent chromium, Cr(VI), colorimetric, 1,5‑diphenylcarbazide, polymers, electronics, alkaline extraction, toluene digestion, spectrophotometry, IEC 62321.