ISO 20130-2018 PDF

Full title and description

ISO 20130:2018 — Soil quality — Measurement of enzyme activity patterns in soil samples using colorimetric substrates in micro‑well plates. This standard specifies a microplate colorimetric method for measuring multiple hydrolase enzyme activities (e.g., arylamidase, arylsulfatase, β‑galactosidase, α‑ and β‑glucosidases, N‑acetyl‑glucosaminidase, acid/alkaline/global phosphatases, urease) in soil sample solutions using 96‑well plates, defined incubation conditions, reaction stopping procedures and spectrophotometric readings.

Abstract

This document provides a standardized procedure to obtain comparable enzyme‑activity profiles from soils by incubating soil solution with defined colorimetric substrates in micro‑wells, stopping reactions by enzyme‑specific reagents, clarifying/centrifuging plate supernatants and measuring absorbance at specified wavelengths to calculate enzyme activity per mass of dry soil. The method is suitable for monitoring seasonal and anthropogenic effects on soil biological functioning and for comparative testing of contaminated or treated soils.

General information

• Status: Published (International Standard; confirmed in periodic review — current edition confirmed by ISO).
• Publication date: July 2018 (2018‑07).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 13.080.30 — Biological properties of soils.
• Edition / version: Edition 1 (2018).
• Number of pages: 29 (ISO published English edition).

Scope

ISO 20130:2018 specifies a laboratory method for the measurement of multiple soil hydrolase activities using colorimetric substrates in micro‑well (96‑well) plates. It covers sample solution preparation, substrates and reagent use, incubation times and temperatures, stopping procedures, centrifugation/clarification, spectrophotometric measurement and calculation of activities expressed per gram of dry soil. The method is intended for soil quality assessment, ecotoxicological screening, monitoring changes in biological activity and comparative testing of contaminated or amended soils.

Key topics and requirements

• Simultaneous (or single) measurement of a panel of hydrolase enzymes (ARN, ARS, β‑GAL, α‑GLU, β‑GLU, NAG, PHOS/PAC/PAK, URE) using colorimetric substrates in microplates.
• Preparation of soil suspensions/solutions, substrate concentrations, calibration curves (para‑nitrophenol, β‑naphthylamine, ammonium chloride) and appropriate blanks/controls.
• Specified incubation temperatures (typically 25 °C ±2 °C or 37 °C ±2 °C depending on the enzyme) and enzyme‑specific incubation times; defined reaction stopping reagents (e.g., Tris buffer pH 12, CaCl2, ethanol + DMCA for naphthylamine assays, salicylate reagent for urease).
• Plate centrifugation and transfer of supernatants to reading plates; absorbance readings at enzyme‑specific wavelengths (examples: 405 nm for PNP, 540 nm for naphthylamine) with microplate spectrophotometers.
• Calculation of enzyme activity in mU (nmol/min) per gram of dry soil using calibration curves, dilution factors, reaction time and dry mass; validation/quality controls to ensure linearity and repeatability.
• Guidance for method validation elements (specificity, sensitivity, linearity, operator effect, limits of quantification) and typical laboratory equipment/consumables (96‑well plates, multichannel pipettes, plate centrifuge, microplate reader).

Typical use and users

Applied by soil and environmental testing laboratories, academic and research institutions, ecotoxicology labs, environmental consultants and agencies performing soil quality monitoring, contamination assessments or experiments that require standardized enzyme‑activity profiling. Typical uses include baseline biological monitoring, impact assessment of pollutants or remediation treatments, and comparative studies across soils or management practices.

Related standards

ISO 20130 sits within the ISO/TC 190 soil‑quality family of standards. Related items include other biological‑property standards (various ISO 18xxx and 23xxx series), ISO/TS 20131 (denitrification enzyme assessments) and sampling and monitoring standards in the ISO 18400 and ISO 16133 families; EN adoption as EN ISO 20130:2020 is noted for regional harmonization.

Keywords

soil quality; enzymatic activity; hydrolases; microplate; colorimetric assay; ISO 20130; soil biology; ecological monitoring; arylamidase; arylsulfatase; β‑galactosidase; glucosidase; NAG; phosphatase; urease.

FAQ

Q: What is this standard?

A: ISO 20130:2018 is an ISO international standard that defines a standardized microplate colorimetric method for measuring multiple enzyme activities in soil samples to support soil biological quality assessment and comparative testing.

Q: What does it cover?

A: It covers sample solution preparation, substrates and standards, incubation conditions, reaction stopping and clarification, spectrophotometric readings, calculation of enzyme activities per dry soil mass, and validation/quality control considerations for the method.

Q: Who typically uses it?

A: Environmental and soil testing laboratories, researchers in soil ecology and biogeochemistry, environmental consultants, and regulatory or monitoring bodies concerned with soil biological indicators.

Q: Is it current or superseded?

A: The document was published in July 2018 (first edition) and is listed by ISO as the current published edition; the ISO catalog indicates the publication has been confirmed in periodic review (status shown as published/confirmed). Users should check national adoption or any subsequent amendments before relying on the text for regulatory use.

Q: Is it part of a series?

A: Yes — it is part of the ISO soil quality suite (ISO/TC 190) addressing biological, chemical and sampling methods for soils; several related technical specifications and standards address specific assays, sampling and ecological assessments (for example ISO/TS 20131 and multiple ISO 18xxx and 23xxx soil standards). It has also been adopted as EN ISO 20130:2020 for European standardization.

Q: What are the key keywords?

A: Soil quality, enzyme activity, colorimetric substrates, microplate assays, hydrolase enzymes, soil biology, monitoring.