The TL-2800 Ammonia Analyzer is a continuous flow system for the detection and analysis of inorganic nitrogen in aqueous solutions. The patented gas diffusion / conductivity principle provides results unaffected by sample turbidity or color. Ultra-sensitive ammonia detection down to the ppb level is easily achievable with a cycle time of 1.5-2.5 minute per sample. The robust system introduces sample via peristaltic pump, which reduces the need for filtration and prevents costly repairs and maintenance issues associated with sample injection valves.  The optional activated zinc reduction cartridge allows for the analysis of nitrate in addition to ammonia.

This analytical approach can be used to measure ammonia in almost any aqueous solution and is ideal where interference issues are a concern.Excellent quantitative results can be obtained on diverse media such as:

• Soil and Plant Tissue Extracts
• Wastewater (EPA ATP Case #: N08-0004)
• Kjeldahl Digestates (no distillation step required!)
• Manure Samples
• Drinking Water
• Urea Analysis via conversion with urease

The integrated data acquisition hardware runs with Microsoft Windows 7 operating system for easy connection to networks, printers, or external USB drives. The intuitive software provides compete automation of the instrument and sampling system with a graphical user interface that is easy to learn and implement.

The TL-2800 is typically paired with an autosampler to facilitate automated operation. Four autosampler options are available to accommodate a wide range of sample volumes.

Principle of Operation

The Timberline TL-2800 Ammonia Analyzer is based on the principle of gas diffusion across a membrane coupled with electrical conductivity measurement as first described by Carlson.¹ The peristaltic pump directs the sample, caustic, and absorbing solutions into the diffusion membrane cell where the sample is mixed with the caustic. The resulting solution has a pH sufficiently high (pH 11-13) to convert virtually all the ammonium ion present in the sample to dissolved ammonia gas. The dissolved ammonia gas in the sample / caustic mixture diffuses across the hydrophobic membrane where it is absorbed by a buffered solution flowing on the inside. The buffered solution then flows into the conductivity detector. The change in electrical conductance of the absorbing solution is proportional to the concentration of ammonium in the original sample. Passing the sample/caustic mixture through an optional zinc reduction cartridge reduces nitrate and nitrite ions to ammonium, allowing measurement of the total inorganic nitrogen concentration.²

¹Carlson, R.M.; Anal. Chem., 50(1978) 1528. ²Carlson, R.M.; Anal. Chem., 58(1986) 1590.