RFQ: Procurement of Ammonia and Amines in Biomethane Analyser

The National Physical Laboratory [NPL] requirement is for a gas chromatography system for the quantitative analysis of ammonia in biomethane.

The purpose of the system is to analyse reference gas standards and low-volume samples at close to atmospheric pressure.

The system must be able to provide matrix independent quantification of the following measurands within a single analytical method: Measurand Limit of quantification required (μmol/mol) Repeatability of measurement at 10 μmol/mol (%) Ammonia ≤10 ≤5 Notes: 1.

It is important to note that the specification is for the qualification limit, and not a detection limit.

2.

The repeatability of the measurement of ammonia at 10 μmol/mol is required to be ≤5%.

3.

The expected matrix gases are as follows: Methane, ethane, propane, carbon dioxide, nitrogen, hydrogen, oxygen, water, terpenes, siloxanes, amines.

These should not interfere with the measurement of ammonia within the measurement method.

It is beneficial (optional requirement) if the system is also capable of measurement of any of the following to ≤1% repeatability within the same method as the ammonia measurement: Measurand Range of quantification required (cmol/mol) Methane 1 - 100 Carbon dioxide 1 - 100 Carbon monoxide 0.1 - 1.0 Nitrogen 1 - 100 Hydrogen 1 - 25 Oxygen 0.001 - 20 Ethane 0.002 - 100 Propane 0.002 - 100 Terpenes < 0.01 Siloxanes < 0.01 Amines < 0.001 Requirement is for quantity of one.