GOST 28995-91 PDF

Full title and description

GOST 28995-91 — Liquefied anhydrous ammonia for industrial use. Determination of water content. Gas chromatographic method. The standard specifies a gas‑chromatographic procedure for determining the mass fraction of water in liquid anhydrous (technical) ammonia by converting water to acetylene and measuring the acetylene by gas chromatography.

Abstract

This interstate (GOST) standard, prepared by the State Agrochemical Association "Agrohím" and adopted by the appropriate Soviet standards authority in 1991, establishes a laboratory method to measure trace water in liquefied anhydrous ammonia (mass fraction range approximately 0.0005% to 0.3%). The procedure covers sampling, reagents (notably calcium carbide), reactor and chromatographic conditions, safety precautions and reporting of results. The standard is harmonized with ISO 7104‑85.

General information

• Status: Active / in force according to available standards databases (no formal withdrawal recorded in referenced sources).
• Publication date: Introduced 01 July 1992 (designation year 1991; approved 29 April 1991).
• Publisher: Interstate (GOST) standards system; approved by the State Committee for Product Quality Management and Standards (Gosstandart) of the USSR; electronic reissue published through national standards publishers.
• ICS / categories: MКC (ICS) 71.100.20; Group L19 (chemical products / industrial gases).
• Edition / version: Original standard dated 1991 (entered into force 1992‑07‑01); reissued text available (reprinted/verified editions from 2004 in national databases).
• Number of pages: Short technical leaflet — typically 7–8 pages depending on publisher/format.

Scope

GOST 28995-91 applies to liquid anhydrous (technical) ammonia intended for industrial use and defines a laboratory gas‑chromatographic method to determine the mass fraction of water in ammonia samples in the approximate range 0.0005% to 0.3% (by mass). The method is based on chemical conversion of water to acetylene using calcium carbide and subsequent quantification of the acetylene peak by gas chromatography. Sampling provisions reference specialized stainless‑steel sample cylinders.

Key topics and requirements

• Scope and applicability to liquid anhydrous ammonia for industrial use; analytical range ~0.0005%–0.3% (mass fraction).
• Sampling: use of special stainless‑steel sampling cylinders and procedures referenced to GOST 6221.
• Chemical conversion: water → acetylene by reaction with calcium carbide (CaC2); preparation and handling of CaC2 described.
• Chromatographic measurement: GC determination of acetylene with specified column packing/stationary phase (e.g., di‑(2‑ethylhexyl) sebacate on silica gel) and chromatographic conditions to resolve acetylene from other gaseous components.
• Apparatus and reagents: reactor design, GC instrumentation, column packing, calibration, and reagent purity requirements.
• Safety and handling: precautions for calcium carbide and acetylene (flammability, storage dry conditions), and safe handling of liquid ammonia (ventilation, protective equipment).
• Reporting and calculation: procedures for calculation of mass fraction, reporting significant figures and uncertainty considerations appropriate for low‑level water determinations.

Typical use and users

Primary users include analytical and quality laboratories at ammonia production plants, fertilizer manufacturers, industrial gas suppliers, petrochemical and refrigeration plants using anhydrous ammonia, inspection and conformity assessment bodies, and research laboratories conducting trace moisture analysis in ammonia. The method is suited for routine quality control, vendor acceptance testing and regulatory compliance checking.

Related standards

GOST 28995-91 was prepared by direct adoption of ISO 7104‑85 and references multiple national GOST documents for sampling, apparatus and reagents. Selected related standards cited in the text include ISO 7104‑85 (basis), GOST 6221 (sampling cylinder), and other GOSTs addressing reagents, apparatus and test methods referenced in the normative references list of the standard.

Keywords

anhydrous ammonia; liquefied ammonia; water content; moisture determination; gas chromatography; acetylene; calcium carbide; GC method; trace analysis; GOST; ISO 7104.

FAQ

Q: What is this standard?

A: GOST 28995-91 is a GOST (interstate) standard that specifies a gas‑chromatographic method for determining the mass fraction of water in liquefied anhydrous (technical) ammonia used in industry.

Q: What does it cover?

A: It covers sampling, reagent and apparatus requirements, the chemical conversion of water to acetylene using calcium carbide, chromatographic separation and measurement of acetylene, calculation and reporting of results, and safety measures for handling reagents and ammonia. The analytical range is approximately 0.0005%–0.3% by mass.

Q: Who typically uses it?

A: Producers and users of industrial ammonia, QA/QC and analytical laboratories, fertilizer manufacturers, industrial gas suppliers, and regulatory/inspection bodies concerned with ammonia quality.

Q: Is it current or superseded?

A: According to major standards repositories and document suppliers, GOST 28995-91 is listed as active/in force and the text has been reprinted or verified in later editions (reissue noted in 2004). No authoritative withdrawal or replacement was identified in the referenced databases at the time of this summary; users should consult the national standards body or current databases for the most up‑to‑date legal status before compliance actions.

Q: Is it part of a series?

A: The standard is aligned with ISO 7104‑85 (it was prepared by direct application of that ISO document) and belongs to the set of GOST standards addressing industrial gases, sampling and analytical methods for chemical quality control.

Q: What are the key keywords?

A: Anhydrous ammonia, liquefied ammonia, water content, gas chromatography, acetylene, calcium carbide, trace moisture, quality control.