ASTM D4629-24 PDF

Full title and description

Standard Test Method for Trace Nitrogen in Liquid Hydrocarbons by Syringe/Inlet Oxidative Combustion and Chemiluminescence Detection — a short analytical standard that defines a syringe or inlet oxidative-combustion procedure with chemiluminescence detection to measure trace total nitrogen in liquid hydrocarbon samples.

Abstract

This standard specifies a method for determination of organically bound (total) nitrogen present at trace levels (typically 0.3 to 100 mg/kg) in liquid hydrocarbons such as naphthas, distillates and oils. Samples are introduced by syringe or inlet, oxidatively combusted to NOx, converted to NO, and quantified by NO–O3 chemiluminescence; the method is intended for process control and quality assurance where low nitrogen concentrations can affect catalytic performance.

General information

• Status: Current.
• Publication date: October 1, 2024.
• Publisher: ASTM International (American Society for Testing and Materials).
• ICS / categories: 75.080 — Petroleum products in general.
• Edition / version: ASTM D4629-24.
• Number of pages: 5 (concise test method document).

(Bibliographic details and DOI: D4629-24; see publisher record for ordering and official text).

Scope

The test method covers determination of trace total nitrogen in liquid hydrocarbons boiling approximately between 50 °C and 400 °C with viscosities roughly 0.2 to 10 cSt, and is applicable to sample matrices such as naphthas, distillates and oils with total nitrogen in the approximate range 0.3 mg/kg to 100 mg/kg. For samples containing more than about 100 mg/kg total nitrogen, alternative methods such as ASTM D5762 or appropriate dilution are recommended. Units are stated in SI.

Key topics and requirements

• Applicable concentration range: nominally 0.3 to 100 mg/kg total nitrogen.
• Sample introduction: syringe injection or inlet/boat introduction into a high-temperature oxidation furnace.
• Combustion and chemistry: oxidative combustion in an inert carrier (argon) with oxygen, conversion of combustion NOx to NO, and detection by NO–O3 chemiluminescence.
• Calibration: use of suitable nitrogen standards and calibration curve covering the working range; attention to solvent and blank control.
• Interferences and sample preparation: solvent compatibility, dilution for high-N samples, and measures to avoid pyrolysis or contamination from syringes or inlets.
• Performance expectations: limits of detection and quantitation appropriate for trace analysis, precision and accuracy established by laboratory validation and proficiency testing.
• Safety and environmental considerations: high-temperature combustion, handling of oxidants and ozone generation, and appropriate ventilation and gas handling practices.

Technical implementation notes and instrument-specific parameters (carrier flows, furnace temperatures, converters, and detector settings) are provided in the official text and should be followed during method setup and validation.

Typical use and users

Commonly used by refinery laboratories, petrochemical process control labs, contract analytical laboratories, catalyst manufacturers and research groups monitoring nitrogen levels in feedstocks and products. The method supports quality control, process monitoring and catalyst protection where trace-bound nitrogen can poison catalysts or impact product specifications.

Related standards

Closely related to other petroleum nitrogen test methods (for example ASTM D5762 for higher total nitrogen concentrations) and to broader elemental analysis standards. The method was developed under ASTM Committee D02 (Petroleum Products, Liquid Fuels, and Lubricants) and may reference laboratory practice and calibration guidance in other ASTM procedures.

Keywords

trace nitrogen, total nitrogen, liquid hydrocarbons, chemiluminescence detection, oxidative combustion, syringe injection, inlet introduction, petroleum, naphtha, distillate, ASTM D4629-24.

FAQ

Q: What is this standard?

A: ASTM D4629-24 is a standardized test method that defines a syringe/inlet oxidative-combustion technique with chemiluminescence detection to determine trace total nitrogen in liquid hydrocarbon samples.

Q: What does it cover?

A: It covers determination of trace total nitrogen in liquid hydrocarbons (approximate boiling range 50–400 °C, viscosity ~0.2–10 cSt) typically in the range 0.3–100 mg/kg, with provisions for sample introduction, combustion, NOx conversion and chemiluminescence detection.

Q: Who typically uses it?

A: Refinery and petrochemical quality/control laboratories, contract testing labs, catalyst manufacturers and analytical instrument vendors and service labs performing trace nitrogen analyses for process control and product specification purposes.

Q: Is it current or superseded?

A: As published October 1, 2024, ASTM D4629-24 is the current active edition; it supersedes the earlier edition (for example the 2017 version). Users should confirm they are using the latest edition from ASTM International for regulatory or contractual work.

Q: Is it part of a series?

A: The method is part of ASTM Committee D02's family of petroleum test methods and is commonly used alongside complementary nitrogen/sulfur test methods (e.g., ASTM D5762) and other elemental analysis procedures.

Q: What are the key keywords?

A: Trace nitrogen, total nitrogen, hydrocarbon, chemiluminescence, oxidative combustion, syringe inlet, ASTM D4629.