ASTM D6512-07 (2014) PDF

Full title and description

Designation: ASTM D6512 − 07 (Reapproved 2014) — Standard Practice for Interlaboratory Quantitation Estimate. This practice describes procedures to compute an interlaboratory quantitation estimate (IQE), a measure of the lowest concentration for which a single measurement from a qualified laboratory will have an estimated specified relative standard deviation across an interlaboratory study.

Abstract

ASTM D6512 provides a uniform statistical procedure and guidance for designing and analysing collaborative (interlaboratory) studies to determine the interlaboratory quantitation capability of analytical methods. The practice defines the IQE (Z% interlaboratory quantitation estimate), describes model selection (constant, straight-line, hybrid) for interlaboratory standard deviation, recommends study designs and outlier-removal procedures, and references the DQCALC adjunct software for calculations.

General information

• Status: Withdrawn (withdrawal recorded in 2023).
• Publication date: Reapproved January 2014 (original designation D6512‑07; current edition approved Jan 15, 2014).
• Publisher: ASTM International (Committee D19 jurisdiction; Subcommittee D19.02 responsible for quality systems, specification, and statistics).
• ICS / categories: Conformity assessment / product and company certification (ICS code referenced in catalog listings).
• Edition / version: D6512 − 07 (Reapproved 2014).
• Number of pages: 15 pages.

Scope

This practice establishes a uniform method for computing the interlaboratory quantitation estimate (IQE) associated with collaborative studies of analytical methods. It is intended for use when the IQE (expressed as a Z% relative standard deviation) provides a suitable measure of quantitation capability across a population of qualified laboratories. The practice excludes avoidable sources of bias and routine errors that can reasonably be detected and corrected, and it applies to methods and matrices studied in a properly planned interlaboratory investigation.

Key topics and requirements

• Definition and computation of IQE (Z% interlaboratory quantitation estimate) as an interlaboratory limit of quantitation.
• Selection and fitting of interlaboratory standard deviation models: constant, straight-line (mean recovery), and hybrid (Rocke & Lorenzato type) models.
• Recommended study designs (e.g., semi-geometric and equi-spaced concentration sets) and minimum numbers of participating laboratories/concentrations for reliable modeling.
• Guidance on outlier detection and removal using accepted, scientifically based procedures (data retention rules and minimum retained datasets).
• Use of adjunct software (DQCALC) and spreadsheet tools for calculation, weighting, and prediction of interlaboratory standard deviations and IQE values.
• Application limits and interpretation: IQE is intended to reflect interlaboratory capability and not to set reporting limits for individual laboratories.

Typical use and users

Practitioners include analytical chemists, standard-method developers, proficiency-test designers, laboratory quality managers, and regulatory or accreditation bodies who need to quantify interlaboratory quantitation capability. Typical uses are designing collaborative studies, comparing quantitation capability of competing methods, and establishing method performance expectations across multiple laboratories.

Related standards

ASTM D6512 references and is used alongside other ASTM practices and guides for interlaboratory study design and interpretation, including Practice D2777 (precision and bias determination), Practice D6091 (interlaboratory detection estimate procedures), and Guide E1763 (interpretation and use of interlaboratory testing results). These related documents support the statistical and procedural elements of D6512.

Keywords

Interlaboratory quantitation estimate, IQE, limit of quantitation, interlaboratory standard deviation, collaborative study, DQCALC, outlier removal, precision and bias, method validation, ASTM D6512.

FAQ

Q: What is this standard?

A: ASTM D6512 − 07 (Reapproved 2014) is a practice that defines and explains how to compute an interlaboratory quantitation estimate (IQE) from collaborative study data to assess the quantitation capability of analytical methods across multiple laboratories.

Q: What does it cover?

A: It covers study design recommendations, statistical model selection for interlaboratory standard deviation (constant, straight-line, hybrid), procedures for outlier handling, computation methods (including use of the DQCALC adjunct), and interpretation of the IQE for interlaboratory method capability.

Q: Who typically uses it?

A: Method developers, analytical laboratories participating in collaborative studies, quality managers, accreditation and regulatory organizations, and statisticians involved in method evaluation and interlaboratory comparisons.

Q: Is it current or superseded?

A: The D6512 practice was reapproved in 2014 but has since been listed as withdrawn; a withdrawal date is recorded in 2023. Users should consult ASTM International for any replacement documents or current guidance before applying the practice.

Q: Is it part of a series?

A: D6512 is part of ASTM Committee D19’s body of standards and is used in conjunction with other D19 practices and guides (for example, D2777 and D6091) that address interlaboratory precision, detection, and interpretation of collaborative testing.

Q: What are the key keywords?

A: IQE, interlaboratory quantitation estimate, limit of quantitation, collaborative study, interlaboratory standard deviation, DQCALC, outlier removal, precision, bias.