ASTM E2310-04 (2015) PDF

Full title and description

Standard Guide for Use of Spectral Searching by Curve Matching Algorithms with Data Recorded Using Mid‑Infrared Spectroscopy. The guide presents the use of spectral searching (comparison of an unknown spectrum against a library of reference spectra) using curve‑matching search algorithms, describes the Euclidean distance and first‑derivative Euclidean distance algorithms, and provides guidance on interpretation, limitations and factors that affect search results.

Abstract

This guide defines spectral searching for mid‑infrared (mid‑IR) data and explains how curve‑matching algorithms (notably the Euclidean distance and first‑derivative Euclidean distance algorithms) are used to rank library spectra against an unknown. It emphasises that spectral searching is a screening/classification tool—not an absolute identification method—and discusses variables that affect search outcomes (baseline, sample purity, Beer’s Law linearity, sample thickness, spectral resolution, data point alignment, library quality and choice of algorithm). Guidance for the use and interpretation of hit quality indices and data‑point matching is provided.

General information

• Status: Withdrawn (ASTM record updated to show withdrawal, June 18, 2024).
• Publication date: Originally approved 2004 (designation E2310 − 04); reapproved and issued as E2310‑04 (Reapproved 2015) — current edition approved May 1, 2015 and published June 2015.
• Publisher: ASTM International.
• ICS / categories: 71.040.50 — Physicochemical methods of analysis (Molecular spectroscopy / infrared).
• Edition / version: Designation E2310‑04; reapproved 2015 (often cited as E2310‑04(2015) or E2310‑04R15).
• Number of pages: 9 pages (document listings commonly show 9 pages; some distributor records list 9–10 pages).

Scope

The guide covers spectral searching procedures for mid‑infrared spectra recorded digitally and intended for screening/classification by comparison with spectral libraries. It addresses algorithm selection and behaviour (Euclidean and first‑derivative Euclidean distance), hit quality indexing, data‑point alignment/interpolation, and practical factors (sample prep, baselines, absorbance linearity, resolution and contaminants) that influence search results. It notes that methods may be applicable to other spectroscopic data types but each must be assessed separately. The guide is intended to assist analysts and is not a substitute for expert spectral interpretation.

Key topics and requirements

• Definition and purpose of spectral searching and spectral libraries (screening/classification rather than absolute ID).
• Descriptions of curve‑matching algorithms: Euclidean distance and first‑derivative Euclidean distance.
• Hit Quality Index (HQI) and hit quality values: ranking and interpretation of library matches.
• Data‑point matching and interpolation methods to align sample and library spectra prior to comparison.
• Factors affecting searches: baseline drifts, sample purity/contaminants, Beer’s Law linearity, sample thickness, instrument resolution, spectral range and library completeness.
• Guidance on limitations and recommended user training—spectral searching should not replace expert judgement.

Typical use and users

Primary users are analytical laboratories, quality control and R&D staff, forensic and materials scientists, and spectroscopists who perform mid‑IR screening against spectral libraries. The guide is used to inform best practices for automated spectral searching and interpretation and to highlight pitfalls for routine users and those integrating library searches into workflows. It is intended for trained personnel who combine automated search results with expert review.

Related standards

The guide references and relates to other ASTM practices and standards for infrared techniques and spectra quality, including Terminology E131, Practice E334, Practice E1252, Practice E1642, Practice E2105 and Practice E2106, among others addressing sample techniques and instrumental performance. These related documents provide complementary procedural and sample‑handling guidance.

Keywords

mid‑infrared, FT‑IR, spectral searching, curve matching, Euclidean distance algorithm, first‑derivative Euclidean, hit quality index, spectral library, interpolation, spectral identification, screening.

FAQ

Q: What is this standard?

A: It is an ASTM standard guide (designation E2310‑04, reapproved 2015) that explains how to use curve‑matching spectral‑search algorithms with mid‑infrared spectral data to compare unknown spectra against reference libraries.

Q: What does it cover?

A: It covers the theory and practical use of spectral search algorithms (Euclidean and first‑derivative Euclidean), hit quality interpretation, data‑point matching/interpolation, and a range of experimental and instrumental factors that affect search outcomes. It emphasises that spectral searching is a screening tool and not a definitive identification method.

Q: Who typically uses it?

A: Analytical laboratories, spectroscopists, forensic analysts, materials scientists, and QC/R&D personnel who perform mid‑IR library searches and need guidance on algorithm behaviour, pitfalls and interpretation.

Q: Is it current or superseded?

A: The document was reapproved in 2015 (E2310‑04R15) but the ASTM record indicates the standard was withdrawn (last updated June 18, 2024) and shows no direct replacement. Users should consult ASTM or their national standards body for the most recent status and any successor guidance.

Q: Is it part of a series?

A: It is part of the ASTM molecular spectroscopy / infrared practice family under Committee E13 (Subcommittee E13.03 on Infrared and Near‑Infrared Spectroscopy) and is cross‑referenced with other IR practice standards (E131, E334, E1252, E1642, E2105, E2106).

Q: What are the key keywords?

A: mid‑infrared, spectral searching, spectral library, Euclidean distance, first‑derivative algorithm, hit quality index, curve matching, FT‑IR, interpolation, screening.